Propane Technician Training Manual

LPG-2 Propane Technician Training Manual

State of Oklahoma College of the Desert West Virginia University

LPG-2 Propane Technician Training Manual

his training manual was created through the hard work and dedication of many organizations and Tindividuals. In 1979 the National Propane Gas Association (NPGA) published an installation and service guidebook: LPG Gas Carburet i o n , commonly known Guidebook 6 . This document was rev i s e d and republished in 1984. The author was Larry Carley. In early 1992, Robert Mahle, a member of the NPGA’s Engine Power Committee, created an ad hoc committee (the Propane Engine Fuel Standards Committee) to revise Guidebook 6 addressing changes in propane motor fuel technology. Combining personal funds with funds from the Office of Transportation Technologies (U.S. Department of Energy ) and Algas Carburetion, Mr. Mahle assembled a cross section of industry and education professionals to pr oduce the first draft of LPG-1. Those individuals are as follows: Dwayne French, Robert Mahle, Colin Me s s e r , Robin Parsons, Bill Pinkerton, Jim Smart, Jim Stout, Roger Wheeler, and Ken Williams. The final pr oduct, LP G - 1 , contains seven chapters and is currently sold and distributed by the NPGA. In 1994, the State of Oklahoma Committee of Alternative Fuels Technician Examiners, College of the Desert, American Society of Advanced Fuel Technologies (ASAFT), and the Wes t e r n Gas Association developed a partnership to produce a curriculum based on LPG-1. The State of Oklahoma prov i d e d Pe t r oleum Violation Escrow Account funds to the Energy Technology Training Center at College of the Desert to write the curriculum. Additional funds were provided by ASAFT, Wes t e r n Gas Association, and Advanced Transportation Technologies Initiative of the California Community Colleges with financial support from the Department of Defense. During the project period, West Vir ginia University received a grant from the U.S. Environmental Protection Agency to produce a similar work. Rather than duplicating ef forts, it was agreed that the project could be done collaboratively; WVU would develop materials specifically for trainers — the instructor notes, pre-and post-tests, student work sheets, overhe a d tr a n s p a r encies, and lab activities. Thanks should also be given to Executive Committee members Robert Mahle, Colin Messer, Robert Myers, William Platz, and Jason Smitherman. Special thanks to Technical Review Committee members Don Bass, Greg Huffman, Fred Moreno, Robin Parsons, Alan Smith, and Roger Wheeler. The LPG 2 Propane Vehicle Training of Trainers program is offe r ed by the National Alternative Fuels Training Program, a project of the National Center for Coal and Energy Research at West Virg i n i a University, administered by Dr. Richard Bajura. The WVU Department of Technology Education is responsible for curriculum development for the Program, as directed by Dr. David McCrory and Dr. George Maughan. Thanks to graduate assistants Steve Macho, Daniel Van Epps, Kimberly Kavanagh, and Douglas Eckert. Also, thanks to graphic artists Karen Norwood, Brian Caudill, Brandon Vallorani, Ter r a h Kelso, and John Hilgerdt. Many thanks to the staff at the NAFTP, including William “Bill” McGlinchey and Albert “Butch” Schrier. Special thanks to Richard “Dick” Riley of Suburban Propane, Bridgeport, OH, and Brian Memmott for their generous contributions to the Prog r a m . This document is ref e r r ed to as LP G - 2 . Its completion is made possible by the dedication of many volunteers and supporters from academia, government, and industry. Additional copies are available fr om the following source s :

Colin Messer, Direc t o r Jeanie Robards National Alternative Fuels Training Prog r a m En e r gy Technology Training Center State of Oklahoma Committee of West Vir ginia University College of the Desert Al t e r native Fuels Technician Examiners 1460 Earl Core Rd. 43-500 Monterey Ave n u e 3301 N. Santa Fe Mo r gantown, WV 26505 Palm Desert, CA 92260 Oklahoma City, OK 73118 (304) 293-7882 (619) 773-2596 (405) 521-4687 Thanks to artist Peter Aschwanden of Santa Fe, NM, for the Professors and Dingbats that adorn this manual. Layout, production and editing by John Hilgerdt, Access Publications, 86 1/2 N. Lexington Avenue, Asheville, NC 28801, 704-252-6588. Many special thanks to Judy Wolgamott, Office Manager, ETTC.

Liquefied Petroleum Gas Training Program

Liquefied Petroleum LPG-2 PROPANE TECHNICIAN TRAINING MANUAL Gas

CONTENTS - MODULES

MODULE 1: PROGRAM PURPOSE & OBJECTIVES MODULE 2: OVERVIEW OF ALTERNATIVE FUELS MODULE 3: PRESSURE AND MEASUREMENT MODULE 4: PRINCIPLES AND PROPERTIES - FUEL THEORY MODULE 5: LEGISLATIVE AND REULATORY POLICIES MODULE 6: BASIC COMBUSTION THEORY MODULE 7: BASIC EMISSIONS AND CONTROLS MODULE 8: LPG FUEL SYSTEMS OVERVIEW THEORY MODULE 9: SAFETY AND REGULATIONS MODULE 10: VEHICLE COMPATIBILITY ANALYSIS MODULE 11: EQUIPMENT LAYOUT & DESIGN MODULE 12: FUEL TANK INSTALLATION MODULE 13: FUEL SUPPLY LINE & INSTALLATION MODULE 14: CONVERTER INSTALLATION MODULE 15: AIR VALVE MIXER & FUEL INJECTION INSTALLATION MODULE 16: ELECTRICAL WIRING, CONNECTIONS, PROTECTION, & ROUTING MODULE 17: FUEL SWITCHING & LEVEL MONITORING MODULE 18: ELECTRONICS INTERFACE MODULE 19: AIR INDUCTION MODULE 20: TANK PURGING & LEAK CHECKING MODULE 21: POST CONVERSION - VEHICLE PERFORMANCE MODULE 22: DRIVER ORIENTATION MODULE 23: FACILITY SAFETY MODULE 24: FUELING STATIONS MODULE 25: TRAINING THE TRAINER GLOSSARY

Liquefied Petroleum Gas Training Program

MODULE 1: Program Purpose and Objectives

State of Oklahoma College of the Desert West Virginia University

Liquefied Petroleum MODULE 1: PROGRAM PURPOSE AND OBJECTIVES Gas

CONTENTS

OBJECTIVES...... 1-i INSTRUCTOR NOTES ...... 1-ii THE FOCUS OF THE PROGRAM...... 1-1 STRATEGY FOR TECHNICIANS ...... 1-1 OVERHEAD TRANSPARENCY MASTERS HANDOUT: SUBURBAN PROPANE: SOME STRAIGHT TALK ABOUT GASEOUS FUELS

PAGE 1-i Liquefied Petroleum MODULE 1: PROGRAM PURPOSE AND OBJECTIVES Gas

OBJECTIVES

At the completion of this module, the technician will be able to: • Describe the purpose of the program and how they can benefit from its training. • Identify strategies for learning the program’s content and training.

Liquefied Petroleum Gas Training Program PAGE 1-ii Liquefied Petroleum MODULE 1: PROGRAM PURPOSE AND OBJECTIVES Gas

INSTRUCTOR NOTES

INSTRUCTOR MATERIALS/MEDIA NEEDED Overhead projector or LCD panel/projection equipment Overhead transparency masters or Microsoft PowerPoint 4.0 presentation file Mod2.ppt

Note: Slides correspond to text as indicated by icon

VCR with TV or projection unit Videotape Segment:NATEF Career Encounters - Alternative Fuels Vehicle Technician, 15:00 or 28:30 minute versions

Note: Videotape segments correspond to text as indicated by icon

Handouts: Suburban Propane: Some Straight Talk About Gaseous Fuels

Note: Handouts correspond to text as indicated by icon

STUDENT MATERIALS/MEDIA NEEDED Module 1: Program Purpose and Objectives

OVERHEAD TRANSPARENCY MASTERS The printouts enclosed with this module are taken from the Microsoft PowerPoint 4.0 presentation file Mod1.ppt . Instructors planning to use overhead projectors should make transparencies from these printouts on a copier (or laser printer designed to safely print to acetate.

Note: Please review Module 25: Training of Trainers for more hints on instructional needs and strategies.

Liquefied Petroleum Gas Training Program PAGE 1-1 Liquefied Petroleum MODULE 1: PROGRAM PURPOSE AND OBJECTIVES Gas

THE FOCUS OF THE PROGRAM Key Points & Notes Public concern for the environment, our nation’s fuel dependency, and the enactment of federal and state clean air initiatives are 1-2 spawning a national alternative fuel industry -– an industry that is becoming vital to our energy security and environmental well-being. Suburban Propane: Some Straight Talk For this industry to grow, skilled technicians must be available to About Gaseous Fuels service the new vehicles. The training program you are attending includes training methods and materials for the conversion and servicing of vehicles fueled by propane. Through training, the NATEF Career program will enlarge the pool of skilled technicians and thereby Encounters: Alternative support broad-scale adoption of alternative fuel technologies. Fuels Vehicle Technician This model approach to delivering training in vehicle conversion, maintenance, safety, and emissions testing has been developed by a multidisciplinary team. The program is instructionally sound and is comprised of easily applied modules that are useful for field use.

STRATEGY FOR TECHNICIANS

READ THE OBJECTIVES Each module begins with a list of objectives intended to give the technician an idea of the scope of the module and to focus on the 1-3 main concepts that should be learned. This is very important because they are what will be tested for later. The objectives are stated in roughly the same order in which they a re covered in the module. Some are concerned with understanding important concepts. These objectives usually require the technician to state the concept and describe or explain it. Other objectives call for applying what has been learned. They usually state the conditions under which the technician should be able to apply the principle or skill. Both types of objectives are important. When beginning each module, it is recommended that the technician read each objective slowly and think about each one. If the technician pauses and thinks about each objective and what each means for 20 or 30 seconds, they will be remembered much longer than if they were merely skimmed over. Some technicians find it helpful to read the objectives two or three times so they have them firmly in mind before they start reading the body of the module.

READ THE BODY OF THE MODULE As the technician reads the module, try to locate the main ideas related to each objective. It is recommend that the main or important concepts be underlined, highlighted, or short notes be written in the Key Points and Notes column. Avoid underlining too much. Most of the content explains the main ideas or gives examples that are designed to help place these ideas into a meaningful context.

Liquefied Petroleum Gas Training Program PAGE 1-2 Liquefied Petroleum MODULE 1: PROGRAM PURPOSE AND OBJECTIVES Gas

Some terms in the text may not be familiar. Please refer to the Key Points & Notes Glossary section or ask the instructor for a definition or example.

CHECK THE MASTERY OF THE MODULE After the technician has finished reading the entire module, return to the objectives and see if the concepts can be stated or carried out as described in each objective. If any of the objectives cannot be mastered, please re-read the sections related to the objective. Use class time and other free time to review the text and discuss it with colleagues, classmates, and the instructor, and then check them again.

COMPLETE THE ACTIVITIES Most of the modules have application objectives as well as concept mastery objectives. A good way to increase skill and check achievement of the application objective is to complete the Activities at the end of most modules.

REVIEW PREVIOUS MODULES As the technician progresses through the modules, occasionally review the objectives and the material read in previous modules. This will help keep the information learned fresh in memory and help if there is a test given later.

PREPARE FOR TESTS If the strategy described above is followed, the technician will find it easy to prepare for the tests. Again, reread the objectives and underlined material once or twice, discuss questionable material with classmates or the instructor, or practice teaching the material to others. Play the role of the instructor and use the objectives to teach “the students” what they should know. Critique each other and refer back to the text for answers.

TAKING THE TESTS The technician should come well prepared to take the test. Make sure to bring all materials called for, such as pencils, rulers, calculators, tools, tissue paper, etc. Try to relax and not become tense. Remember the objectives and skills that have been stated, for questions concerning their mastery will most likely be on the test. Re-read each question before answering it. There may be an obvious wrong answer, and a process of elimination may be used to arrive at the right answer. Think the question through, or go on to the next and return later using a different approach to recalling the answer to it. Finally, if time go back and answer each question again and review the reasoning behind why it was answered that way.

Liquefied Petroleum Gas Training Program PAGE 1-3 Liquefied Petroleum MODULE 1: PROGRAM PURPOSE AND OBJECTIVES Gas

TEST EVALUATION Key Points & Notes When the tests are returned, see which questions were answered incorrectly. Go back to the text or activity to find the correct answer, or discuss the problems with the instructor. It is important that these problems be corrected now (in class), for outside of the class there may not be the opportunity for errors. Get it right now.

Liquefied Petroleum Gas Training Program PAGE 1-4 Liquefied Petroleum MODULE 1: PROGRAM PURPOSE AND OBJECTIVES Gas

Key Points & Notes

Liquefied Petroleum Gas Training Program 1 MODULE 1: Program Purpose and Objectives 2 THE FOCUS OF THE PROGRAM • National alternative fuel industry • Need for skilled technicians • LPG II program 3 STRATEGY FOR TECHNICIANS • Read the objectives • Read the body of the module • Check the mastery of the module • Complete the activities • Review previous modules • Prepare for tests • Take the tests • Evaluate answers

MODULE 1: Program Purpose and Objectives

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 1-1

THE FOCUS OF THE PROGRAM

• National alternative fuel industry • Need for skilled technicians • LPG II program

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 1-2

STRATEGY FOR TECHNICIANS

• Read the objectives • Read the body of the module • Check the mastery of the module • Complete the activities • Review previous modules • Prepare for tests • Take the tests • Evaluate answers

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 1-3

MODULE 2: Overview of Alternative Fuels

State of Oklahoma College of the Desert West Virginia University

Liquefied Petroleum MODULE 2: OVERVIEW OF ALTERNATIVE FUELS Gas

CONTENTS

OBJECTIVES...... 2-i INSTRUCTOR NOTES ...... 2-ii PROMOTING UNITED STATES ENERGY RESOURCES AND REDUCING OUR DEPENDENCE ON FOREIGN OIL ...... 2-1 THE ALTERNATIVE FUELS...... 2-1 CHARACTERISTICS OF METHANOL VEHICLES...... 2-1 CHARACTERISTICS OF ETHANOL VEHICLES...... 2-2 CHARACTERISTICS OF ELECTRIC VEHICLES...... 2-2 CHARACTERISTICS OF NATURAL GAS VEHICLES (NGV)...... 2-3 CHARACTERISTICS OF LIQUEFIED PETROLEUM GAS VEHICLES...... 2-3 HYBRID VEHICLES & HYBRID (DUAL FUEL) ENGINES ...... 2-5 MODULE REVIEW ITEMS ...... 2-9 MRI SCORING KEY ...... 2-11 OVERHEAD TRANSPARENCY MASTERS HANDOUTS: PROPANE: THE FUEL OF CHOICE FOR THE 21ST CENTURY FUEL FACTS: FUEL WEIGHT PER GALLON FUEL FACTS: PROPANE MOTOR FUEL BREAK-EVEN CHART FUEL FACTS: NUMBER OF ALTERNATIVE FUELED VEHICLES WORLDWIDE FUEL FACTS: NUMBER OF ALTERNATIVE FUELED VEHICLES IN THE UNITED STATES

Liquefied Petroleum Gas Training Program

PAGE 2-i Liquefied Petroleum MODULE 2: OVERVIEW OF ALTERNATIVE FUELS Gas

OBJECTIVES

At the completion of this module, the technician will be able to: • Identify and briefly describe the importance of promoting United States energy resources. • Identify the similar and conflicting characteristics of alternative fuel technologies versus characteristics of gasoline. • Identify the characteristics of methanol vehicles. • Identify the characteristics of ethanol vehicles. • Identify the characteristics of electric vehicles. • Identify the characteristics of a Natural Gas Vehicles (NGV). • Identify the characteristics and advantages of Liquefied Petroleum Gas vehicles (LPG).

Liquefied Petroleum Gas Training Program PAGE 2-ii Liquefied Petroleum MODULE 2: OVERVIEW OF ALTERNATIVE FUELS Gas

INSTRUCTOR NOTES

INSTRUCTOR MATERIALS/MEDIA NEEDED Overhead projector or LCD panel/projection equipment Overhead transparency masters or Microsoft PowerPoint 4.0 presentation file Mod2.ppt

Note: Slides correspond to text as indicated by icon

Videotape Segment #1: ABC News segment on Alternative Fuel Vehicles, 4 minutes VCR with TV or projection unit

Note: Videotape segments correspond to text as indicated by icon

Handouts: Propane: The Fuel of Choice for the 21st Century Fuel Facts: Fuel Weight Per Gallon Fuel Facts: Propane Motor Fuel Break-Even Chart Fuel Facts: Number of Alternative Fueled Vehicles Worldwide Fuel Facts: Number of Alternative Fueled Vehicles in the United States

Note: Handouts correspond to text as indicated by icon

STUDENT MATERIALS/MEDIA NEEDED Module 2: Overview of Alternative Fuels

MODULE REVIEW ITEMS The Module Review Items (MRI) are designed to allow for flexibility in their use. The exam may be utilized as a post-module review, pre/post test, part of a term examination, or it may be used by the student if the module is used as a self study text.

OVERHEAD TRANSPARENCY MASTERS The printouts enclosed with this module are taken from the Microsoft PowerPoint 4.0 presentation file Mod2.ppt . Instructors planning to use overhead projectors should make transparencies from these printouts on a copier (or laser printer designed to safely print to acetate.

Note: Please review Module 25: Training of Trainers for more hints on instructional needs and strategies.

Liquefied Petroleum Gas Training Program PAGE 2-1 Liquefied Petroleum MODULE 2: OVERVIEW OF ALTERNATIVE FUELS Gas

PROMOTING UNITED STATES ENERGY RESOURCES AND Key Points & Notes REDUCING OUR DEPENDENCE ON FOREIGN OIL Demands on the transportation sector to help alleviate the problems of rising fuel costs and pollution are increasing every year. 2-2 Transportation fuel accounts for 24 percent of the energy demand ABC News segment in the United States. This accounts for 18 percent of the Gross on Alternative Fuel National Product (GNP). The United States spends $55 billion a Vehicles, 4 minutes year on oil imports, 60 percent of which is consumed by the transportation sector. Imported fuel is subject to limitations and price controls by foreign countries. Inexpensive domestic fuel alternatives could help reduce costs considerably. See Table 2-1. Th e r e also are indirect costs associated with use of petrol e u m - b a s e d fuels. According to the American Lung Association, two-thirds of the population in the U.S. breates air above established safe emission levels. The U.S. spends an estimated $45 billion on health care as a result of air pollution. A large portion of that amount results from pollutants released by the transportation sector. Over 100 cities fail gr ound level ozone standards and over 40 fail carbon monoxide rates. Adopting clean fuel technologies and sound transportation policies ar e necessary to achieve a cleaner environment. In order to make i n f o rmed decisions about appropriate alternative fuels, fleet operators must know the diffe r ences among the various clean fuel te c h n o l o g i e s .

THE ALTERNATIVE FUELS The six alternative fuels currently considered are methanol, ethanol, liquefied petroleum gas, electricity, natural gas, and 2-3 hydrogen. In this module we will compare methanol, ethanol, propane, and natural gas to gasoline. See Table 2-2. 2-4

CHARACTERISTICS OF METHANOL VEHICLES Methanol has been used as a transportation fuel worldwide for several decades. The United States has a large domestic supply. 2-5 - 2-8 Methanol is a non-carcinogenic, corrosive, toxic, and water-soluble fuel; it is produced from natural gas, coal, residual oil, or biomass. It is less flammable than gasoline and burns cleanly in an engine, resulting in lower emission levels. Vehicles can be purchased from some automotive manufacturers, or methanol conversions are

Fuel Feed and Return Hose 2-9

Throttle Body Modified Fuel Cap Engine Control Module

Fuel Sender and Pump

Stainless Steel Special Engine Oil Fuel Tank Flame Arresters Catalytic Converter West Virginia University 2-1 Methanol car.

Liquefied Petroleum Gas Training Program PAGE 2-2 Liquefied Petroleum MODULE 2: OVERVIEW OF ALTERNATIVE FUELS Gas possible, but very expensive. Methanol engines accumulate more Key Points & Notes iron and lead in the oil, which decreases its lubrication ability. T h e re f o re, special engine oil is used. Engine wear, re p a i r, maintenance, and overall life cycle costs are comparable to gasoline powered vehicles. Engines tend to run cooler on methanol. Operators can expect a 10 percent increase in horsepower. More fuel storage capacity is needed for the vehicle to obtain the same range as gasoline. The methanol to gasoline storage ratio is generally 1.7 to 1. Figure 2-1 shows the basic components of a methanol-fueled vehicle.

CHARACTERISTICS OF ETHANOL VEHICLES Ethanol has been used throughout the world as a transportation fuel for several decades, primarily in South America. Currently, an 2-10 - 2-14 estimated 2.5 million ethanol vehicles are operated worldwide. The United States has a large domestic supply of ethanol harvested from energy crops (primarily corn and sugar cane) and municipal solid waste. Ethanol is less corrosive than methanol. It burns cleanly in an engine, resulting in lower emission levels than gasoline. Ethanol conversions are possible, but they are very expensive. Ethanol vehicles must use a special engine oil. Engine wear, repair, maintenance, and overall life cycle costs are comparable to gasoline-powered vehicles. More fuel storage capacity is needed for the vehicle to obtain the same range as gasoline. The ethanol to gasoline storage ratio is generally 1.4 to 1. The basic components of an ethanol-fueled vehicle are shown in Figure 2-2.

Stainless Steel and Teflon Coated Fuel Lines 2-15 Special Piston Rings, Modified Fuel Gaskets and Fuel Injectors Inlet Hose Advanced Electronic Control System Variable Fuel Sensor

Noncorrosive Stainless Special Catalytic Steel Exhaust Converter Fuel Tank West Virginia University 2-2 Ethanol car.

CHARACTERISTICS OF ELECTRIC VEHICLES Thousands of electric vehicles (EVs) are operating in the United States. EVs are powered by electricity stored in batteries. Current 2-16 - 2-19 battery recharging usually takes about 8 to 10 hours. The primary advantages of EVs are drastic reductions in noise and emission levels. However, EVs do not perform as well as gasoline vehicles. The driving range of an EV averages between 50 and 70 miles before its batteries must be recharged. This range is affected by cold temperatures, vehicle load, and terrain. Fuel cost for electricity is estimated to be between 60 cents and 80 cents compared to an

Liquefied Petroleum Gas Training Program PAGE 2-3 Liquefied Petroleum MODULE 2: OVERVIEW OF ALTERNATIVE FUELS Gas

Key Points & Notes Battery Pack Electric Motor Battery Pack 2-20

Electric Wires Transmission West Virginia University 2-3 Electric car. equivalent gallon of gasoline. Battery weight, performance, and capacity are challenging EV development. It is estimated that EVs require 50 percent less maintenance than gasoline powered vehicles because the prime mover has fewer mechanical parts. The basic components of an electric-powered vehicle are shown in Figure 2-3.

CHARACTERISTICS OF NATURAL GAS VEHICLES (NGV) Natural gas has been used as a transportation fuel for more than 50 years. The United States has an abundant domestic supply of 2-21 natural gas and an extensive distribution system to residences. Natural gas costs about $6 per million Btu. Compressing natural gas increases its stored energy and its cost. This is called CNG – compressed natural gas. The ratio of stored energy to volume is greater for CNG than for an equivalent gasoline gallon. It also takes more weight to store a gasoline gallon equivalent of CNG because of the large, heavy pressurized gas storage cylinders, which might be six times bigger and heavier than the stored energy equivalent of gasoline. Chilling natural gas to -260o F creates liquefied natural gas (LNG).

Pressure Relief Vent 2-24

Check Lockoff Air/Fuel Natural Gas Valve Solenoid Mixer Fill Valve Throttle Body

High Pressure CNG Cylinders Manual Shutoff Valve West Virginia University 2-4 Natural gas car.

This increases the energy content of natural gas and extends vehicle range. LNG has great motor fuel potential. Some distinct advantages of Natural Gas Vehicles (NGVs) include low fuel costs and low emissions. Natural gas burns much cleaner 2-22

Liquefied Petroleum Gas Training Program PAGE 2-4 Liquefied Petroleum MODULE 2: OVERVIEW OF ALTERNATIVE FUELS Gas

Key Points & Notes Baseline is a gasoline-fueled vehicle with enough fuel to travel 100 miles. Distance shown based on relative BTUs of each fuel 2-25 gallon. If all vehicles were fitted with equal volume tanks, gasoline would require the least fillups on a trip, followed by propane.

GASOLINE 100 Mi

PROPANE 80-90 Mi

ETHANOL 70 Mi

METHANOL 54 Mi

CNG 21 Mi West Virginia University

2- 5 Driving range comparison of identical vehicles optimized for their specific fuel. than gasoline, resulting in reduced emission levels, less contamination of engine oil and spark plugs, and longer engine life. CNG and LNG are considered very safe; conversion, however, can be expensive. Vehicles that operate on either gasoline or natural gas 2-23 are called bi-fuel vehicles. Natural gas appears to be one of the most promising alternative fuels because of its vast domestic supply. The basic components of a NGV are shown in Figure 2-4.

CHARACTERISTICS OF LIQUEFIED PETROLEUM GAS VEHICLES Liquefied petroleum gas (LPG) has been used as a transportation fuel for more than 60 years. The United States has more than 2-26 - 2-27 350,000 LPG vehicles of the estimated 3.5 million vehicles used worldwide. Liquefied petroleum gas is a by-product of natural gas processing and crude oil refining. It is an odorless and colorless gas composed primarily of propane and butane with minor fractions of other hydrocarbons. In the United States, LPG is primarily composed of propane; thus, it is usually referred to as propane gas.

2-31 Filter Convertor Shutoff Lockoff Vaporizer- Air/Fuel Valve Regulator Mixer LPGFill and/or Solenoid Valve Throttle Body

LPG Tank Hydrostatic Relief Valve West Virginia University 2-6 LPG Car.

Liquefied Petroleum Gas Training Program PAGE 2-5 Liquefied Petroleum MODULE 2: OVERVIEW OF ALTERNATIVE FUELS Gas

The distribution infrastructure necessary for supporting a major Key Points & Notes LPG vehicle market is well developed. LPG burns cleanly, resulting in lower emission levels than gasoline, lower maintenance costs, and prolonged engine life. LPG has a 2-28 higher octane rating than gasoline and can operate under a higher compression ratio, but there is a power loss of about 5 to 15 percent because of lower volumetric efficiency. LPG demonstrates good cold weather-starting capabilities and is generally safer than vehicles operating on gasoline. Figure 2-6 shows the basic components of an LPG-fueled vehicle. Use of LPG as a vehicle fuel began in 1913, primarily in farm equipment and grew in the 1950s as an indoor vehicular fuel (fork 2-29 lifts and cleaning equipment). LPG vehicles on the road today are primarily retrofitted gasoline vehicles similar to the NGV market. Pick-up trucks and medium duty trucks are the most common vehicle types converted to LPG. Fuel in these vehicles is stored under pressure as a liquid. Gasoline vehicle conversions to LPG cost from $1,500 to $2,500 and involve the installation of a fuel storage tank in the trunk, truck bed, or mounted on the frame. Several engine compartment modifications are required. In contrast to NGV, most LPG converted vehicles are dedicated fuel vehicles, although many bi-fuel vehicles are in operation. Not all vehicles are appropriate for LPG conversions. Consider the following suggestions when you plan LPG conversions: 2-30 • Heavy duty trucks are excellent candidates for LPG because of the Propane: The Fuel of favorable energy density of LPG. Choice for the 21st • Automobiles are least desirable for LPG conversions when storage Century space and fuel availability are considered. Fuel Facts: Fuel • Carbureted vehicles, which are generally pre-1985 models or older, are not as efficient as fuel-injected engines when converted Weight Per Gallon to LPG. Fuel Facts: Propane • Newer vehicles with computer diagnostic systems make better Motor Fuel Break- choices for LPG conversion because they have built-in emission control capability. Even Chart • Dedicated LPG vehicles are more efficient and generally perform Fuel Facts: Number of better than bi-fuel vehicles because their components are custom- Alternative Fueled tuned for a single fuel. Vehicles Worldwide HYBRID VEHICLES & HYBRID (DUAL FUEL) ENGINES Fuel Facts: Number of Propane has good potential as motor fuel used in dual fuel and Alternative Fueled hybrid vehicle applications. In a hybrid vehicle, an internal Vehicles in the United combustion engine, fueled by natural gas, propane, gasoline or States diesel, powers an electric generator. The engine is set to run at most efficient load and RPM. Electricity powers motors at the wheels. Batteries or other storage devices are wired into the system to provide smooth power generation and performance. Electronic sensors, controllers, and actuators monitor and control the operation. More sophisticated systems store energy from flywheel and vehicle mass inertia, electrically or hydraulically. Re-generative

Liquefied Petroleum Gas Training Program PAGE 2-6 Liquefied Petroleum MODULE 2: OVERVIEW OF ALTERNATIVE FUELS Gas braking captures and generates kinetic energy. Key Points & Notes In a hybrid engine diesel is used to ignite natural gas or propane. Because the diesel engine is so thermally efficient, it is a good candidate as a dual fuel/hybrid power source for on and off the road engines. A dual fuel diesel, natural gas or propane engine can be very clean and equal the power of a mono-fuel diesel engine. These systems are currently available. Do not confuse a hybrid/dual fuel engine with a hybrid vehicle.

Liquefied Petroleum Gas Training Program PAGE 2-7 Liquefied Petroleum MODULE 2: OVERVIEW OF ALTERNATIVE FUELS Gas

Coal Exported Energy 2.32 4.58

Coal Other 21.91 2.26

Residential & Coal Commercial Use Natural Gas 19.62 19.23 32.07 Fossil Fuels 57.40 Natural Crude Oil Domestic Gas Fossil 13.82 Production 22.20 Fuels 71.16 Total 76.47 Total Industrial Supply Consumption 95.19 90.62 Use NG PL 2.44 34.47 Nuclear 7.15 Petroleum 34.62 Renewables 6.60

Imported Transportation Crude Oil & Energy Nuclear 7.15 Use Products 18.94 22.44 24.06 Renewables 6.88

Adjustments 1.59 Other 3.50 Environmental Information Agency

Table 2-1 U.S. Energy Flow, 1995 (Quadrillion Btu).

300K

250K

200K

LPG

NG 150K ALCOHOL

ELECTRIC 100K

50K

0 1992 1993 1994 1995 1996 1997 Energy Information Administration Table 2-2 Estimated number of alternative-fueled vehicles in use in the U.S., by fuel.

Liquefied Petroleum Gas Training Program PAGE 2-8 Liquefied Petroleum MODULE 2: OVERVIEW OF ALTERNATIVE FUELS Gas

Key Points & Notes

Liquefied Petroleum Gas Training Program PAGE 2-9 Liquefied Petroleum MODULE 2: OVERVIEW OF ALTERNATIVE FUELS Gas

MODULE REVIEW ITEMS

Note to Technician: Consider all choices carefully and select the best answer to each. 1. Which five appear to be the most promising transportation fuels with respect to efficiency, safety, cost, and supply? A. Methane, ethanol, hydrogen, LPG, and electricity. B. Methanol, electricity, NG, hydrogen, and solar. C. Ethanol, LPG, NG, nuclear, and electricity. D. Methanol, ethanol, LPG, electricity, and NG.

2. Transportation fuels account for what percentage of the energy demand in the United States? A. 80%. B. 50%. C. 30%. D. 45%.

3. The United States spends an estimated _____ a year on oil imports? A. $52 million. B. $52 billion. C. $45 million. D. $45 billion.

4. Which of the following is the most convincing reason to convert a vehicle to LPG? A. LPG burns cleanly. B. Large domestic supplies are available. C. The distribution infrastructure is well established. D. All of the above.

5. LPG is a by-product of _____. A. Propane. B. Butane. C. Natural gas processing and crude oil refining. D. None of the above.

6. The distribution infrastructure necessary for supporting a major LPG vehicle market is well developed. A. True. B. False.

7. What is the advantage(s) of LPG over gasoline? A. LPG burns cleanly. B. LPG has a higher octane rating. C. LPG is safer than gasoline. D. All of the above.

8. When converting a vehicle to LPG all of the following are considerations except: A. Mileage. B. Driving range. C. Year of the vehicle. D. Carrying capacity of the vehicle.

Liquefied Petroleum Gas Training Program PAGE 2-10 Liquefied Petroleum MODULE 2: OVERVIEW OF ALTERNATIVE FUELS Gas

9. When choosing an alternative fuel for vehicle conversion, which of the following is an important consideration? A. Costs. B. Refueling infrastructure. C. Associated maintenance. D. All of the above.

10. All of the alternative fuels discussed have the following in common except _____. A. All are domestically produced. B. All are recommended for every type of vehicle conversion. C. All could reduce air pollution. D. All are in large supply.

11. Generally, vehicle models 1985 and newer are more efficient for conversion because _____. A. They are larger. B. They have fuel injection systems. C. They have onboard computer diagnostic systems. D. B & C.

12. A vehicle fueled by methanol could be identified by which of the following components? A. Stainless steel fuel tank. B. Manual shutoff valve. C. Flame arresters. D. None of the above.

13. A vehicle fueled by ethanol could be identified by which of the following components? A. Stainless steel fuel tank. B. Stainless steel and Teflon-coated fuel lines. C. Flame arresters. D. Battery pack.

14. A vehicle fueled by compressed natural gas could be identified by which of the following components? A. Pressure relief valve. B. Manual shutoff valve. C. High pressure cylinders. D. All of the above.

15. A vehicle fueled by LPG could be identified by which of the following components? A. Tank. B. Hydrostatic relief valve. C. Air/fuel mixer. D. All of the above.

Liquefied Petroleum Gas Training Program PAGE 2-11 Liquefied Petroleum MODULE 2: OVERVIEW OF ALTERNATIVE FUELS Gas

MRI SCORING KEY

1. D 2. C 3. B 4. D 5. C 6. A 7. D 8. A 9. D 10. B 11. D 12. A 13. B 14. D 15. D

Liquefied Petroleum Gas Training Program

1 MODULE 2: Overview of Alternative Fuels 2 PROMOTING US ENERGY RESOURCES AND REDUCING OUR DEPENDENCE ON FOREIGN OIL • Transportation fuel accounts for 24% US energy demands • Accounts for 18% GNP • $55B spent for oil imports • 60% for transportation uses • 2/3 US population breathe unsafe emission levels • $45B spent on health care due to air pollution • 100+ cities fail ozone; 40+ fail CO • Need for domestic fuel use 3 THE ALTERNATIVE FUELS • Methanol • Ethanol • Electricity • Natural Gas (NG) • Hydrogen • Liquefied Petroleum Gas (LPG) 4 ALTERNATIVE FUEL VEHICLES • Methanol vehicles • Ethanol vehicles • Electric vehicles (EVs) • Natural Gas vehicles (NGV) • Liquefied Petroleum Gas (LPG) vehicles 5 METHANOL VEHICLE CHARACTERISTICS • Noncarcinogenic • Corrisive • Toxic • Water-soluable

6 METHANOL VEHICLE CHARACTERISTICS Advantages: • Large fuel supply • Less flammable than gasoline • Burns cleanly • Some methanol OEM vehicles available 7 METHANOL VEHICLE CHARACTERISTICS Drawbacks: • Expensive conversions • Needs special oil • Accumulates more iron and lead in the oil 8 METHANOL VEHICLE CHARACTERISTICS Technical: • Engine wear, repair, maintenance, overall life cycle comparable to gasoline vehicles • Cooler running engines • Up to 10% HP increase • Methanol to Gasoline storage ratio: 1.7:1 9 2-1 METHANOL CAR 10 ETHANOL VEHICLE CHARACTERISTICS • Less corrisive than methanol • 2.5M ethanol vehicles worldwide 11 ETHANOL VEHICLE CHARACTERISTICS Produced from: • Energy crops (corn, sugar cane, etc.) • Municipal solid wastes 12 ETHANOL VEHICLE CHARACTERISTICS Advantages: • Burns cleanly 13 ETHANOL VEHICLE CHARACTERISTICS Drawbacks: • Expensive conversions • Need special engine oil 14 ETHANOL VEHICLE CHARACTERISTICS Technical: • Engine wear, repair, maintenance, overall life cycle comparable to gasoline vehicles • Ethanol to gasoline storage ratio: 1.4:1 15 2-2 ETHANOL CAR 16 ELECTRIC VEHICLE CHARACTERISTICS Electricity: • Powered from batteries, generators, or hybrids • Hundreds of US electric vehicles 17 ELECTRIC VEHICLE CHARACTERISTICS Advantages: • Reduced noise and emissions • Fuel cost $.60-.80 per equivalent gallon of gasoline • $24.65 per million Btu 18 ELECTRIC VEHICLE CHARACTERISTICS Drawbacks: • Limited driving range before recharge • Affected by cold temps, load, and terrain • Slower acceleration 19 ELECTRIC VEHICLE CHARACTERISTICS Technical: • 50% less maintenance than gasoline vehicles 20 2-3 ELECTRIC CAR 21 NATURAL GAS VEHICLE CHARACTERISTICS Natural Gas: • Large domestic supply • Extensive distribution infrastructure 22 NATURAL GAS VEHICLE CHARACTERISTICS Advantages: • Burns cleanly • Low fuel costs • Affordable conversion costs • $6 per million Btu 23 NATURAL GAS VEHICLE CHARACTERISTICS Technical: • Vehicle can operate on NG or gasoline • Excellent safety record 24 2-4 NATURAL GAS CAR 25 2-5 DRIVING RANGE COMPARISONS Baseline is a gasoline-fueled vehicle with enough fuel to travel 100 miles. Distance shown based on relative BTUs of each fuel gallon. If all vehicles were fitted with equal volume tanks, gasoline would require the least fillups on a trip, followed by propane.

GASOLINE 100 Mi PROPANE 80-90 Mi ETHANOL 70 Mi METHANOL 54 Mi CNG 21 Mi West Virginia University

2-5 Driving range comparison of identical vehicles optimized for their specific fuel. 26 LIQUEFIED PETROLEUM GAS VEHICLE CHARACTERISTICS LPG: • 350,000 US LPG vehicles • Infrastructure can support vehicle fuel supply • Odorless • Colorless • Started as farm and heavy duty equipment fuel 27 LIQUEFIED PETROLEUM GAS VEHICLE CHARACTERISTICS Produced from: • By-product of natural gas processing and crude oil refining • Composed of propane, butane, or a mix 28 LIQUEFIED PETROLEUM GAS VEHICLE CHARACTERISTICS Advantages: • Burns cleanly • Higher octane rating • Good cold weather starting • Good safety record • Conversions work well with onboard computer systems • Vans and trucks- good conversion candidates 29 LIQUEFIED PETROLEUM GAS VEHICLE CHARACTERISTICS Drawbacks: • Loss of 5% HP • Not for cars when mileage range is a factor • Customized dedicated vehicles better than bi-fuel • Carbureted conversions not as efficient as fuel injected 30 LIQUEFIED PETROLEUM GAS VEHICLE CHARACTERISTICS Technical: • Engine wear, repair, maintenance, overall life cycle better than gasoline vehicles • Conversion costs: $1500-$2500 31 2-6 LIQUEFIED PETROLEUM GAS CAR

MODULE 2: Overview of Alternative Fuels

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 2-1

PROMOTING US ENERGY RESOURCES AND REDUCING OUR DEPENDENCE ON FOREIGN OIL

• Transportation fuel accounts for 24% US energy demands • Accounts for 18% GNP • $55B spent for oil imports • 60% for transportation uses • 2/3 US population breathe unsafe emission levels • $45B spent on health care due to air pollution • 100+ cities fail ozone; 40+ fail CO • Need for domestic fuel use

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 2-2

THE ALTERNATIVE FUELS

• Methanol • Ethanol • Electricity • Natural Gas (NG) • Hydrogen • Liquefied Petroleum Gas (LPG)

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 2-3

ALTERNATIVE FUEL VEHICLES

• Methanol vehicles • Ethanol vehicles • Electric vehicles (EVs) • Natural Gas vehicles (NGV) • Liquefied Petroleum Gas (LPG) vehicles

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 2-4

METHANOL VEHICLE CHARACTERISTICS

• Noncarcinogenic • Corrisive • Toxic • Water-soluable

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 2-5

METHANOL VEHICLE CHARACTERISTICS

Advantages: • Large fuel supply • Less flammable than gasoline • Burns cleanly • Some methanol OEM vehicles available

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 2-6

METHANOL VEHICLE CHARACTERISTICS

Drawbacks: • Expensive conversions • Needs special oil • Accumulates more iron and lead in the oil

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 2-7

METHANOL VEHICLE CHARACTERISTICS

Technical: • Engine wear, repair, maintenance, overall life cycle comparable to gasoline vehicles • Cooler running engines • Up to 10% HP increase • Methanol to Gasoline storage ratio: 1.7:1

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 2-8

2-1 METHANOL CAR

Fuel Feed and Return Hose

Throttle Body Engine Control Modified Fuel Cap Module

Fuel Sender and Pump

Stainless Steel Special Engine Fuel Tank Flame Arresters Catalytic Converter Oil

West Virginia University

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 2-9

ETHANOL VEHICLE CHARACTERISTICS

• Less corrisive than methanol • 2.5M ethanol vehicles worldwide

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 2-10

ETHANOL VEHICLE CHARACTERISTICS

Produced from: • Energy crops (corn, sugar cane, etc.) • Municipal solid wastes

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 2-11

ETHANOL VEHICLE CHARACTERISTICS

Advantages: • Burns cleanly

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 2-12

ETHANOL VEHICLE CHARACTERISTICS

Drawbacks: • Expensive conversions • Need special engine oil

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 2-13

ETHANOL VEHICLE CHARACTERISTICS

Technical: • Engine wear, repair, maintenance, overall life cycle comparable to gasoline vehicles • Ethanol to gasoline storage ratio: 1.4:1

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 2-14

2-2 ETHANOL CAR

Stainless Steel and Teflon Coated Fuel Lines Special Piston Rings, Modified Fuel Gaskets and Fuel Injectors Inlet Hose Advanced Electronic Control System

Variable Fuel Sensor

Noncorrosive Stainless Steel Special Catalytic Fuel Tank Exhaust Converter West Virginia University

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 2-15

ELECTRIC VEHICLE CHARACTERISTICS

Electricity: • Powered from batteries, generators, or hybrids • Hundreds of US electric vehicles

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 2-16

ELECTRIC VEHICLE CHARACTERISTICS

Advantages: • Reduced noise and emissions • Fuel cost $.60-.80 per equivalent gallon of gasoline • $24.65 per million Btu

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 2-17

ELECTRIC VEHICLE CHARACTERISTICS

Drawbacks: • Limited driving range before recharge • Affected by cold temps, load, and terrain • Slower acceleration

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 2-18

ELECTRIC VEHICLE CHARACTERISTICS

Technical: • 50% less maintenance than gasoline vehicles

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 2-19

2-3 ELECTRIC CAR

Battery Pack Electric Motor Battery Pack

Electric Wires Transmission West Virginia University

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 2-20

NATURAL GAS VEHICLE CHARACTERISTICS

Natural Gas: • Large domestic supply • Extensive distribution infrastructure

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 2-21

NATURAL GAS VEHICLE CHARACTERISTICS

Advantages: • Burns cleanly • Low fuel costs • Affordable conversion costs • $6 per million Btu

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 2-22

NATURAL GAS VEHICLE CHARACTERISTICS

Technical: • Vehicle can operate on NG or gasoline • Excellent safety record

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 2-23

2-4 NATURAL GAS CAR

Pressure Relief Vent Check Lockoff Air/Fuel Natural Gas Valve Solenoid Mixer Fill Valve

Throttle Body

High Pressure CNG Cylinders Manual Shutoff Valve West Virginia University

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 2-24

2-5 DRIVING RANGE COMPARISONS

Baseline is a gasoline-fueled vehicle with enough fuel to travel 100 miles. Distance shown based on relative BTUs of each fuel gallon. If all vehicles were fitted with equal volume tanks, gasoline would require the least fillups on a trip, followed by propane.

GASOLINE 100 Mi

PROPANE 80-90 Mi ETHANOL 70 Mi

METHANOL 54 Mi CNG 21 Mi West Virginia University

2-5 Driving range comparison of identical vehicles optimized for their specific fuel.

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 2-25

LIQUEFIED PETROLEUM GAS VEHICLE CHARACTERISTICS

LPG: • 350,000 US LPG vehicles • Infrastructure can support vehicle fuel supply • Odorless • Colorless • Started as farm and heavy duty equipment fuel

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 2-26

LIQUEFIED PETROLEUM GAS VEHICLE CHARACTERISTICS

Produced from: • By-product of natural gas processing and crude oil refining • Composed of propane, butane, or a mix

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 2-27

LIQUEFIED PETROLEUM GAS VEHICLE CHARACTERISTICS

Advantages: • Burns cleanly • Higher octane rating • Good cold weather starting • Good safety record • Conversions work well with onboard computer systems • Vans and trucks- good conversion candidates

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 2-28

LIQUEFIED PETROLEUM GAS VEHICLE CHARACTERISTICS

Drawbacks: • Loss of 5% HP • Not for cars when mileage range is a factor • Customized dedicated vehicles better than bi-fuel • Carbureted conversions not as efficient as fuel injected

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 2-29

LIQUEFIED PETROLEUM GAS VEHICLE CHARACTERISTICS

Technical: • Engine wear, repair, maintenance, overall life cycle better than gasoline vehicles • Conversion costs: $1500-$2500

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 2-30

2-6 LIQUEFIED PETROLEUM GAS CAR

Filter Lockoff Convertor Shutoff and/or Vaporizer- Air/Fuel Valve Solenoid Regulator Mixer LPG Fill Valve Throttle Body

LPG Tank Hydrostatic Relief Valve West Virginia University

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 2-31

MODULE 3: Pressure and Measurement

State of Oklahoma College of the Desert West Virginia University

Liquefied Petroleum MODULE 3: PRESSURE AND MEASUREMENT Gas

CONTENTS

OBJECTIVES...... 3-i INSTRUCTOR NOTES ...... 3-ii PRESSURE ...... 3-1 BOILING POINT...... 3-1 ATMOSPHERIC OR BAROMETRIC PRESSURE...... 3-1 POSITIVE AND NEGATIVE PRESSURE...... 3-1 MEASUREMENT...... 3-2 POUNDS PER SQUARE INCH (PSI)...... 3-2 INCHES OF MERCURY (IN. HG.)...... 3-3 INCHES OF WATER COLUMN (IN. WC)...... 3-4 PRESSURE DIFFERENTIAL ...... 3-5 THE THROTTLE...... 3-5 MODULE REVIEW ITEMS...... 3-7 MRI SCORING KEY...... 3-9 OVERHEAD TRANSPARENCIES MASTERS

Liquefied Petroleum Gas Training Program

PAGE 3-i Liquefied Petroleum MODULE 3: PRESSURE AND MEASUREMENT Gas

OBJECTIVES

At the completion of this module, the technician will be able to: • Identify and contrast weight (mass) versus volume (displacement). • Discuss fuel density. • Discuss the measurement of a cubic foot as applied to air, fuel and combustibles. • Discuss pressure, volume and temperature. • Discuss atmosphere and altitude. • Discuss the throttle.

Liquefied Petroleum Gas Training Program PAGE 3-ii Liquefied Petroleum MODULE 3: PRESSURE AND MEASUREMENT Gas

INSTRUCTOR NOTES

INSTRUCTOR MATERIALS/MEDIA NEEDED Overhead projector or LCD panel/projection equipment Overhead transparency masters or Microsoft PowerPoint 4.0 presentation file Mod3.ppt

Note: Slides correspond to text as indicated by icon

STUDENT MATERIALS/MEDIA NEEDED Module 3: Pressure and Measurement

OVERHEAD TRANSPARENCY MASTERS The printouts enclosed with this module are taken from the Microsoft PowerPoint 4.0 presentation file Mod3.ppt . Instructors planning to use overhead projectors should make transparencies from these printouts on a copier (or laser printer designed to safely print to acetate.

Note: Please review Module 25: Training of Trainers for more hints on instructional needs and strategies.

Liquefied Petroleum Gas Training Program PAGE 3-1 Liquefied Petroleum MODULE 3: PRESSURE AND MEASUREMENT Gas

PRESSURE Key Points & Notes BOILING POINT The temperature at which any liquid boils depends on the pressure surrounding it. The boiling point also depends on the composition 3-2 or make-up of the fuel, which is described later in this course. For example, at sea level water boils at 212o F (100o C). At high elevations where the atmospheric pressure is lower, water boils at a lower temperature. 0 feet at sea level water boils at 212o F (100o C) 7000 feet above sea level water boils at 205o F (96o C). Gasoline is converted from a liquid to a gas by vaporization, either in the atmosphere or in the combustion chamber of an engine. Gasoline reaches a vapor state when it boils or vaporizes as it flows past the intake valve. Gasoline boils at 80o to 300o F (27o–150o C) at atmospheric pressure. Propane boils at -44o F (-42o C). We know that liquids tend to evaporate faster when the temperature is high (and the air is dry). NOTE: Propane is stored in a liquid state under pressure. At atmospheric pressure propane is a vapor, so in most carburetion systems, it is a vapor before it reaches the engine - unless it is injected into the intake as a liquid. One propane system, not described in this manual, injects liquid propane into the intake manifold ports where it vaporizes.

ATMOSPHERIC OR BAROMETRIC PRESSURE Consider atmospheric pressure – also called barometric pressure. At sea level, the pressure of the atmosphere is typically 14.69 pounds per square inch absolute (psia). At 7000 feet above sea level, the atmospheric pressure is 12.3 psia. To simplify things round out 14.69 psia to 15.0 psia and 12.3 psia to 12.0. 15.0 psia (atmospheric pressure at sea level) and 12.0 psia (at 7000 ft above sea level).

POSITIVE AND NEGATIVE PRESSURE Pressures above (greater than >) atmospheric pressure are positive pressures. Engine vacuum – the pressure in the intake manifold of a running engine – is below (< less than) atmospheric pressure and is considered negative pressure. This is important in understanding how an engine works and how to fix an engine that doesn’t. Remember, an engine is basically an air pump. Technicians need to understand pressures and their measurement to diagnose fuel and electrical problems. This is especially important in regard to gaseous fuels like propane because most of the propane carburetors on the road (and off-road) operate on these principles.

Liquefied Petroleum Gas Training Program PAGE 3-2 Liquefied Petroleum MODULE 3: PRESSURE AND MEASUREMENT Gas

Positive pressure: Key Points & Notes Any absolute pressure higher than the existing atmospheric pressure – 3-3 Boost pressure (absolute)

Over atmospheric pressure – Boost Existing pressure (gauge) atmospheric pressure 4 A T M O S P H E R I C PRESSURE BASE Negative pressure: Pressure Also Differential suction, vacuum – 5 Vacuum Gauge (VAC) Negative Pressure: Any absolute pressure that is lower than the existing atmospheric pressure – Manifold absolute pressure gauge (MAP)

1 2 3

ABSOLUTE ZERO PRESSURE BASE Co u r tesy of Don Bass

3-1 Bar graph demonstrating the two bases for pressure measurement. Note that suction bar (bar 5) is the pressure differential between the existing atmospheric pressure bar (bar 2) and an absolute pressure that is lower than the existing atmospheric pressure (bar 3).

MEASUREMENT POUNDS PER SQUARE INCH (PSI) Tire gauges, air compressor gauges, fuel pump gauges, and vacuum gauges are read in what is called gauge pressur e. Imagine a car 3-4 tire inflated to 30 psi (psig). Tire pressure is measured with a gauge that reads 0 psi when it’s not connected to the valve stem. Even though 15.0 psi of atmospheric pressure surrounds the gauge, it reads zero. A tire gauge reads in pounds per square inch gauge (psig). When disconnected, it’s not reading any pressure so it reads 0 psig. When the tire gauge is connected to the valve stem it might read 30 psig. If that gauge were an absolute pressur e gauge, it would read 45.0 psia at sea level – tire pressure plus atmospheric pressure . 30.0 psi (tire gauge pressure) + 15.0 psi (atmospheric pressure) = 45.0 psia. Refer to Figure 3-1.

Liquefied Petroleum Gas Training Program PAGE 3-3 Liquefied Petroleum MODULE 3: PRESSURE AND MEASUREMENT Gas

INCHES OF MERCURY (in. Hg.) Key Points & Notes If a gauge reads atmospheric pressure in addition to tire, air, fuel or intake manifold pressure, it reads in absolute pressure. Airplane pilots have absolute gauges on their instrument panels that tell THE VACUUM GAUGE them the exact manifold pressure at whatever altitude they fly. IS ACTUALLY A That way the pilot doesn’t have to do difficult calculations while D I F F E R E N T I A L flying the plane. However, the absolute pressure gauges that pilots PRESSURE GAUGE. IT use read in inches of mercury (in. Hg.) as do the vacuum gauges we MEASURES THE DIF- use to measure intake manifold vacuum. Inches of mercury is a FERENCE BETWEEN finer, more precise unit of measurement than psi. For example: ATMOSPHERIC AND LESS THAN AT M O- 1 psi = 2.04 in. Hg. SPHERIC PRESSURE. 1 in. Hg. = 0.491 psi For simplification, we round out 2.04 to 2.0 in. Hg . and 0.491 to 0.5 psi. Question: Technician A says that moist air is heavier than dry air. Technician B says that dry air is heavier than moist air. Who is correct? Technician B. NOTE: Dry air is heavier than moist air; moist air is lighter than dry air. Humid air contains less oxygen than dry air. After a rain storm when the sun comes out, look at the top of a wooden fence. You will see the lighter, moist vapor rising out of the top of the wood slats. The specific gravity of completely dry air (0 percent humidity) is 1.00; the specific gravity of air that is completely wet (100 percent humity) is 0.625. Technicians are familiar with engine vacuum gauges, which read inches of Mercury (in. Hg.). A vacuum gauge connected to an intake manifold of an idling engine that is in good condition at sea level might read about 20.0 in. Hg. That same engine at 7000 ft. above sea level at idle might read 14.0 in. Hg. Why did the value drop?

3-5

Peter Aschwanden 3-2 Reading scan tool at sea level while idling in neutral.

Liquefied Petroleum Gas Training Program PAGE 3-4 Liquefied Petroleum MODULE 3: PRESSURE AND MEASUREMENT Gas

Key Points & Notes

3-6

Peter Aschwanden 3-3 Reading scan tool at 7000 ft. above sea level while idling in neutral.

Rule of thumb – Atmospheric pressure drops 1 in. Hg. for every 1000 ft. rise in altitude. This translates to roughly a 3 percent loss of power for every 1000 ft. rise. Remember, atmospheric pressure (or barometric pressure) drops as altitude increases. In other words, air weighs less at higher altitudes. Atmospheric pressure at sea level might be 30.0 in. Hg. (15.0 psia) and 24.0 in. Hg. (12.0 psia) at 7000 ft. Likewise, the pressure (or vacuum) under the throttle drops. So, if the engine intake manifold vacuum is 20.0 in. Hg. (10.0 psig) at sea level, it might be around 14.0 in. Hg. (7.0 psig) at 7000 ft. above sea level. This knowledge is essential because the propane carburetion business talks a lot about psi and in. Hg. Technicians work with manifold absolute pressure and barometric absolute pressure as well as intake manifold vacuum. Manifold absolute pressure (or MAP) is the difference between barometric pressure (or BAP) and engine vacuum (VAC). For example, the intake manifold vacuum of an idling engine at sea level might be 20 in. Hg.; the MAP of that same engine would be 10 in. Hg. 30 in. Hg. atmospheric (barometric) pressure – BAP -20 in. Hg. manifold vacuum – VAC 10 in. Hg. manifold absolute pressure – MAP BAP (-) minus VAC (=) equals MAP. The parasitic load on the engine stays almost the same at sea level and at 7000 feet so the manifold absolute pressure remains the same at both altitudes. Manifold vacuum drops at high altitude because the difference between atmospheric and manifold absolute pressure changes.

Liquefied Petroleum Gas Training Program PAGE 3-5 Liquefied Petroleum MODULE 3: PRESSURE AND MEASUREMENT Gas

INCHES OF WATER COLUMN (in. WC) Key Points & Notes Propane carburetion work uses a more precise (finer) unit of measurement than in. Hg. - inches of water column (in. WC or in. H20). 1 psi = 2.04 in Hg. = 27.72 in.WC; so 1 psi = 27.72 inches or water column Simplified and rounded off it would be: 1 psia = 2.0 in. Hg. = 27.72 in WC

PRESSURE DIFFERENTIAL When air passes through an air filter element, the restriction created by the element creates a drop in pressure. This drop can be measured. If one end of the water manometer were connected to the inlet of the air filter housing and the other end to the outlet of the housing, a pressure differential could be measured with the engine running, perhaps 0.5 – 3.0” WC. As the filter gets dirty, the pressure differential across the filter element increases. The float bowl in a gasoline carburetor is pressurized by the atmosphere. A venturi in a gasoline carburetor creates a pressure drop that is used to draw fuel from a float bowl. In propane carburetion, this is called a signal; it operates the regulator allowing gas to pass into the mixer (carburetor) and engine. A pressure drop is generated in an air valve carburetor by the air valve assembly to meter fuel in response to engine RPM and load.

WATER MANOMETER MERCURY MANOMETER 3-7

15 15.7* 13.86 PSIA in. Hg.

oz / in .WC PSIG 1.02 sq. in. 1.02 0

1.02” Hg. + 1.02” Hg. = Positive 2.04” Hg. pressure * PSIA is pounds per square inch absolute. This is: 14.7 (sea 13.86 13.86” WC + 13.86” WC = level) + 1.0 psi = 15.7 15 27.72” WC Don Bass 3-4 Measurements in psig, oz./sq. in., in. WC and in. Hg.

Liquefied Petroleum Gas Training Program PAGE 3-6 Liquefied Petroleum MODULE 3: PRESSURE AND MEASUREMENT Gas

When the throttle of an engine is closed, at idle, the differential Key Points & Notes between atmospheric pressure (above the throttle) and intake manifold pressure (below the throttle) is a pressure differential. This is usually measured in inches of mercury. THE THROTTLE Question: What does the throttle actually do? Technician A says that it controls the volume of air and fuel that enters the engine. 3-8 Technician B claims the throttle controls the weight or mass of the air and fuel entering the engine. Who is right? Technician B.

Carburetors are rated by volumetric capacity (cubic feet per minute). This specifies the volume of air in one minute a carburetor can flow at a given pressure drop through the carburetor. An engine will consume more cubic feet at WOT (higher RPM) than at idle. At WOT, the air-fuel mixture is heavier (greater mass) so the engine runs faster. As rev- olutions per minute increase, the consumption of air in cubic feet (volume) increases. The volume per intake stroke never changes; the number of intake strokes per minute change, as the throttle position and weight of air-fuel changes.

Technician A doesn’t understand the difference between volume and mass. An engine breathes a fixed volume on any given intake stroke whether the throttle is closed or wide open. The engine responds to the density or mass of the air-fuel mixture; the engine runs slower at idle when the mixture is less dense and faster at WOT when the mixture is more dense. Imagine a closed throttle – at idle – on a carburetted or throttle body (central point) fuel injected engine. If the pressure above the closed throttle at sea level is 15 psia (30 in. Hg.), and the MAP (manifold absolute pressure) below the throttle is 7.5 psia (15 in. Hg.), then the pressure under the throttle is half of barometric or atmospheric

3-9

15 psia 15 psia (30 in. Hg.) (30 in. Hg.)

15 psia 7.5 psia (30 in. Hg.) (15 in. Hg.) 2000 RPM 2000 RPM WOT DECELERATION

Michele Ortega 3-5: Throttle positions – WOT and Idle.

Liquefied Petroleum Gas Training Program PAGE 3-7 Liquefied Petroleum MODULE 3: PRESSURE AND MEASUREMENT Gas pressure. The weight or mass of the air under the throttle is half the weight of the air above the throttle. P1V1 = P2V2 When the throttle is opened wide (WOT), 1 cu.ft. x 15 psia = 15 psia the pres s u r e under the throttle equalizes 2 cu.ft. x 7.5 psia = 15 psia with the pres s u r e above it. At WOT, the THE CUBIC FOOT ABOVE THE pre s s u r e under the throttle is 15 psia (30 THROTTLE DOUBLES UNDER THE in. Hg.). Remember, at higher altitudes, THROTTLE TO 2 CUBIC FEET, EACH WEIGHING EXACTLY 1/2 THE ORIG- liquids boil at lower temperatures where INAL CUBIC FOOT th e r e is less pres s u r e. At idle, gasoline below the throttle vaporizes more easily than at WOT. At WOT, the pres s u r e under the throttle is equal to atmospheric pres s u r e. This is a problem on carburetted gasoline engines when temperature and the intake manifold are cold. To en s u r e smooth operation, an extra rich fuel-air ratio is used to pr ovide enough vaporized fuel so the engine doesn’t stumble when accelerated. An accelerator pump does the same thing so when the th r ottle opens suddenly MAP increases and vaporization decrea s e s . See Heat of Vaporization and Latent Heat in glossary. Pr opane, on the other hand, enters the engine already vaporized. Th e re f o r e, it isn’t necessary to heat the intake manifold as it is on a gasoline engine. The colder the propane air-fuel charge, the better – because the charge is denser and contains more mass of combustible en e rg y . It is important to understand that the throttle controls the weight (mass) of the air-fuel charge entering the engine at any given RPM. Use a scan tool or vacuum gauge to watch changes in MAP (manifold absolute pres s u r e) and VAC (intake manifold vacuum) on a running engine. Compare these readings with throttle position and engine RPM under diffe r ent engine loads. Question: Why does an empty compressed air tank float on water when pressurized by only atmospheric pres s u r e and sink when pr essurized with 1000 psi compressed air?

Liquefied Petroleum Gas Training Program PAGE 3-8 Liquefied Petroleum MODULE 3: PRESSURE AND MEASUREMENT Gas

Key Points & Notes

Liquefied Petroleum Gas Training Program PAGE 3-9 Liquefied Petroleum MODULE 3: PRESSURE AND MEASUREMENT Gas

MODULE REVIEW ITEMS

Note to Technician: Consider all choices carefully and select the best answer to each.

1. Pressures above atmospheric pressure are _____ pressures. A. Positive. B. Negative. C. High. D. Low.

2. Engine vacuum (the pressure in the intake manifold of a running engine is _____ atmospheric pressure and is consider _____ pressure. A. Below, positive. B. Above, positive. C. Below, negative. D. None of the above.

3. Atmospheric pressure _____ as altitude increases. A. Weigh less. B. Raises. C. Drops. D. Remains constant.

4. Air weighs more at higher altitudes. A. True. B. False.

5. Determine the manifold absolute pressure (MAP) in. Hg. if the atmospheric pressure (BAP) is 45 in. Hg. and the manifold vacuum (VAC) is 25 in. Hg. A. 65 in. Hg. B. 20 in. Hg. C. 12 in. Hg. D. None of the above.

6. At atmospheric pressure propane is a _____. A. Liquid. B. Vapor.

7. Atmospheric pressure is also referred to a _____ pressure. A. Negative. B. Positive. C. Barometric. D. None of the above.

8. If the pressure of the atmosphere is typically 15.0 psia at sea level, the atmosphere should be about _____ psia at 7000 ft above sea level. A. 13.0 psia. B. 0 psia. C. 25 psia. D. None of the above.

Liquefied Petroleum Gas Training Program PAGE 3-10 Liquefied Petroleum MODULE 3: PRESSURE AND MEASUREMENT Gas

9. The vacuum gauges used to measure intake manifold pressure read inches of _____. A. Mercury (Hg). B. Water column (WC). C. Pounds per square inch absolute (psia). D. None of the above.

10. In propane carburation work, which unit of measurement is used? A. Inches of mercury (Hg). B. Inches of water column (WC). C. Pounds per square inch absolute (psia). D. None of the above.

11. What does the throttle do? A. It controls the volume of air and fuel that enters the engine B. It controls the weight or mass of the air and fuel entering the engine C. A & B D. None of the above

12. At closed throttle, the pressure above the throttle is _____ the air below the throttle. A. Greater than. B. Less than. C. The same as. D. None of the above.

13. When the throttle is opened wide, the pressure under the throttle _____ with the pressure above it. A. Raises. B. Lowers. C. Equalizes. D. None of the above.

14. At wide open throttle, the pressure under the throttle is equal to atmospheric pressure. A. True. B. False.

15. Which of the following reasons could explain why the colder the propane air/fuel charge, the better? A. The charge is less dense and contains less mass of combustible energy. B. The charge contains more volume of combustible energy. C. The charge is denser and contains more mass of combustible energy. D. None of the above.

Liquefied Petroleum Gas Training Program PAGE 3-11 Liquefied Petroleum MODULE 3: PRESSURE AND MEASUREMENT Gas

MRI SCORING KEY

1. A 2. C 3. C 4. B 5. B 6. B 7. C 8. A 9. A 10. B 11. B 12. A 13. C 14. A 15. C

Liquefied Petroleum Gas Training Program

1 MODULE 3: Pressure and Measurement 2 PRESSURE • Boiling point temperature varies with pressure – Propane stored as a liquid under pressure • Atmospheric or barometric pressure • Positive pressure • Negative pressure 3 3-1 PRESSURE MEASUREMENT 4 MEASUREMENT • Pounds Per Square Inch (PSI) – Gauge pressure (psig) – Absolute pressure (psia) • Inches of Mercury (In. Hg.) – 1 psi = 2.04 in. Hg. – Manifold absolute pressure (MAP) – Barometric absolute pressure (BAP) • Inches of Water Column (In. WC) • Pressure Differential 5 3-2 SCAN TOOL AT SEA LEVEL 6 3-3 SCAN TOOL AT 7000 FT 7 3-4 MEASUREMENTS 8 THE THROTTLE • The throttle controls the weight or mass of the air and fuel entering the engine

•P1V1 = P2V2 • 1 cu.ft. x 15 psia = 15 psia • 2 cu.ft. x 7.5 psia = 15 psia • The cubic foot above the throttle doubles under the throttle to 2 cubic feet, each weighing exactly 1/2 the original cubic foot 9 3-5 THROTTLE POSITIONS

MODULE 3: Pressure and Measurement

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 3-1

PRESSURE

• Boiling point temperature varies with pressure – Propane stored as a liquid under pressure • Atmospheric or barometric pressure • Positive pressure • Negative pressure

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 3-2

3-1 PRESSURE MEASUREMENT

Courtesy of Don Bass College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 3-3

MEASUREMENT

• Pounds Per Square Inch (PSI) – Gauge pressure (psig) – Absolute pressure (psia) • Inches of Mercury (In. Hg.) – 1 psi = 2.04 in. Hg. – Manifold absolute pressure (MAP) – Barometric absolute pressure (BAP) • Inches of Water Column (In. WC) • Pressure Differential

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 3-4

3-2 SCAN TOOL AT SEA LEVEL

Peter Aschwanden

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 3-5

3-3 SCAN TOOL AT 7000 FT

Peter Aschwanden

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 3-6

3-4 MEASUREMENTS

Courtesy of Don Bass College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 3-7

THE THROTTLE

• The throttle controls the weight or mass of the air and fuel entering the engine

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 3-8

3-5 THROTTLE POSITIONS

15 psia 15 psia (30 in. Hg.) (30 in. Hg.)

15 psia (30 in. Hg.) 7.5 psia 2000 RPM (15 in. Hg.) 2000 RPM WOT DECELERATION

Michele Ortega

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 3-9

MODULE 4: Principles And Properties – Fuel Theory

State of Oklahoma College of the Desert West Virginia University

Liquefied Petroleum MODULE 4: PRINCIPLES AND PROPERTIES – FUEL THEORY Gas

CONTENTS

OB J E C T I V E S...... 4 - i INSTRUCTOR NOTES...... 4 - i i PHYSICAL CHARACTERISTICS & PROPERTIES OF ENGINE FUELS...... 4-1 HIGH AND LOW HEAT VALUES...... 4-1 HEAT CONTENT...... 4-2 ODORANT...... 4-2 SPECIFIC GRAVITY AND DENSITY...... 4-2 BOILING POINT, TEMPERATURE AND PRESSURE...... 4-3 EXPANSION RATIO...... 4-4 FLAMMABILITY LIMITS...... 4-5 COMBUSTION AIR-FUEL RATIO...... 4-6 HISTORY OF LP-GAS AS AN ENGINE FUEL ...... 4-6 CHANGES IN THE FUEL BLEND...... 4-7 OCTANE RATINGS...... 4-7 COMBUSTION CHARACTERISTICS...... 4-8 EMISSIONS...... 4-10 ENGINE PERFORMANCE...... 4-10 ENGINE MAINTENANCE AND LIFE...... 4-11 SAFETY CONSIDERATIONS FOR LPG...... 4-12 ORIGINS OF LPG...... 4-12 AVAILABILITY OF LPG & THE CHARACTERISTICS OF ITS INFRASTRUCTURE ...... 4-13 WORLD VIEW ON LPG AND WHO IS USING LPG VEHICLES...... 4-13 LPG AS A MOTOR FUEL ...... 4-14 ADVANTAGES OF LPG...... 4-14 DISADVANTAGES OF LPG VEHICLES...... 4-14 WHY FLEET OPERATORS SHOULD BE INTERESTED IN LPG VEHICLES...... 4-14 MODULE REVIEW ITEMS...... 4-21

Liquefied Petroleum Gas Training Program Liquefied Petroleum MODULE 4: PRINCIPLES AND PROPERTIES – FUEL THEORY Gas

CONTENTS

MRI SCORING KEY...... 4 - 2 5 HANDOUTS: FUEL FACTS: FUEL COMPARISONS BY VOLUME (GALLONS) AND BY WEIGHT (POUNDS) FUEL FACTS: PROPANE SUPPLY AND DEMAND OVERHEAD TRANSPARENCY MASTERS

Liquefied Petroleum Gas Training Program PAGE 4-i Liquefied Petroleum MODULE 4: PRINCIPLES AND PROPERTIES – FUEL THEORY Gas

OBJECTIVES

At the completion of this module, the technician will be able to: • Discuss the history of LP-Gas as an engine fuel. • Identify the changes that have taken place in LP-gas fuel blend. • Identify the growth of LP-gas as a motor fuel in recent years. • Discuss the physical characteristics and properties of LP-gas. • Identify safety considerations when using LP-gas as a motor fuel. • Discuss the availability of LPG and the characteristics of its infrastructure. • Discuss the world view on LPG and identify who is using LPG vehicles. • Evaluate the advantages and disadvantages of LPG. • Identify why fleet operators should be interested in LPG vehicles.

Liquefied Petroleum Gas Training Program PAGE 4-ii Liquefied Petroleum MODULE 4: PRINCIPLES AND PROPERTIES – FUEL THEORY Gas

INSTRUCTOR NOTES

INSTRUCTOR MATERIALS/MEDIA NEEDED Overhead projector or LCD panel/projection equipment Overhead transparency masters or Microsoft PowerPoint 4.0 presentation file Mod4.ppt

Note: Slides correspond to text as indicated by icon

VCR with TV or projection unit

Handouts: Fuel Facts: Fuel Comparisons By Volume (Gallons) and By Weight (Pounds) Fuel Facts: Propane Supply and Demand

Note: Handouts correspond to text as indicated by icon

STUDENT MATERIALS/MEDIA NEEDED Module 4: Principles and Properties - Fuel Theory

OVERHEAD TRANSPARENCY MASTERS The printouts enclosed with this module are taken from the Microsoft PowerPoint 4.0 presentation file Mod4.ppt . Instructors planning to use overhead projectors should make transparencies from these printouts on a copier or laser printer designed to safely print to acetate.

Note: Please review Module 25: Training of Trainers for more hints on instructional needs and strategies.

Liquefied Petroleum Gas Training Program PAGE 4-1 Liquefied Petroleum MODULE 4: PRINCIPLES AND PROPERTIES – FUEL THEORY Gas

PHYSICAL CHARACTERISTICS & PROPERTIES OF ENGINE FUELS Key Points & Notes An explanation of the basic chemistry involved in the properties of hydrocarbons leads to a better understanding of how and why one 4-2 fuel differs from another. Like gasoline and diesel fuel, propane is a member of the hydrocarbon (HC) family. HCs are substances whose molecular structure is composed primarily of hydrogen and carbon. There are literally thousands of different HCs, ranging from those found in asphalts, heavy oils and waxes to gasoline, kerosene, and naphtha and gases such as propane, butane, ethane, and methane. Gasoline consists of 40 to 400 or more different HCs.

H H H H H H 4-3

H c H H c c H H c c c H

H H H H H H

CH4 – Methane C2H6 – Ethane C3H8 – Propane

H H H H H H H H H H H

H c c c c H H c c c c c c c H

H H H H H H H H H H H

C4H10 – Butane C7H16 – Heptane (Gasoline) John Hilgerdt 4-1 Hydrocarbon Molecules

The number and arrangement of hydrogen and carbon atoms in a fuel’s molecular structure is what gives each fuel its set of physical properties. Refer to Figure 4-1. At atmospheric pressure, propane (C3H8), butane (C4H10) and methane (CH4) are gases because of their relatively low molecular weight. At atmospheric pressure, gasoline, kerosene, and diesel fuel are liquids because their molecules are much larger and heavier.

While gasoline can have many diffe r ent hydrocarbons in its

makeup, LPG is composed of mostly propane (C3H8). Th e te r ms propane and LPG are used interchangeably. EPA has established standards for commercial Propane/LPG. Motor quality LPG, for automotive use, should be 95% propane with the remaining 5% other hydrocarbons, and inert gases. The LPG technician should know that the variation in perce n t a g e of propane content can affect engine perfo r mance and emissions. The percentage of propane (C4H8) in LPG can vary in diffe r ent parts of the country and seasonally.

HIGH AND LOW HEAT VALUES Every hydrocarbon fuel has a low and high heat value. The high heat value is the total Btus contained in the fuel, including the Btus 4-4

Liquefied Petroleum Gas Training Program PAGE 4-2 Liquefied Petroleum MODULE 4: PRINCIPLES AND PROPERTIES – FUEL THEORY Gas that are lost to heat of vaporization. Heat of vaporization is the Key Points & Notes amount of heat needed to vaporize liquid fuel into a gaseous fuel. Heat of vaporization also vaporizes water to steam. With propane, this happens in the combustion chamber. The high heat value of a pound of propane is 21,650 Btus; the low heat value is 19,920 Btus. The energy lost to converting the water in propane is 1730 Btus. (21,650–19,920 = 1730 Btus). Low heat value is what counts; it is the energy that the engine responds to on the Btus remaining in the fuel after the heat of vaporization.

HEAT CONTENT Generally speaking, the greater the number of carbon atoms in a molecule of a given fuel, the greater the heat content (Btus – British 4-5 Ter mal Units) or energy value of the fuel. One Btu is equal to the heat req u i r ed to raise the temperature of one pound of water one de g r ee Fahrenheit. Table 4-A includes a comparison of the prop e r t i e s of various fuels. Note the diffe r ence in Btu values among these fuels by volume and weight. The numbers in Tables 4-B show how much heat is produced in Btus when a given quantity of propane is burne d by weight and by volume. A gallon of propane/butane blend might pr oduce 91,500 Btus of heat energy when burned, compared to 114,000 Btus per gallon for gasoline. On the other hand, a pound of blended LPG might produce 21,000 Btus, which is more than a pound of gasoline (19,000 Btus). Propane produces more heat energy than gasoline on a per pound basis; yet, it weighs over two pounds less per gallon than gasoline. An engine’s horsepower output depends on the quantity of fuel burned, and even though propane requires a leaner air-fuel mixture than gasoline, the net outcome is that it takes more propane to achieve the same power output. Engines converted to propane will generally consume a little more fuel in terms of miles per gallon when operated under the same conditions. However, many of today’s modern electronic fuel injected engines converted to propane are capable of fuel economies similar to gasoline.

ODORANT Propane, like butane or methane, is odorless. An odorant (usually ethyl mercaptan) is added to give propane its very distinctive, 4-6 pungent smell. The odorant acts as a warning agent so that leaks can be detected quickly. It is not harmful to breathe nor does it affect the composition of the fuel in any way except to make its vapors noticeable. Once the fuel is burned, the odor disappears. Ten thousand gallons of propane require one pint of odorant.

SPECIFIC GRAVITY AND DENSITY Another important characteristic of propane is how the specific gravity compares to other liquids and gases such as water and air. 4-7

The specific gravity of a liquid is defined as a comparison of the Fuel Facts: Fuel weight of a given volume of one liquid to the weight of an identical Comparisons By Volume volume of water, measured at the same temperature and pressure. (Gallons) and By Weight For the purposes of comparison, water has a specific gravity of 1.0. (Pounds) A liquid that is twice as heavy would have a specific gravity of 2.0.

Liquefied Petroleum Gas Training Program PAGE 4-3 Liquefied Petroleum MODULE 4: PRINCIPLES AND PROPERTIES – FUEL THEORY Gas

Key Points & Notes

4-8

PROPANE AIR

PROPANE WATER

LIQUID VAPOR 4-2 The specific gravity of liquid propane is less than water, and the specific gravity of propane vapor is greater than air.

A liquid that is half as heavy as water would have a specific gravity of 0.5. In Table 4-B, the specific gravity for propane is 0.504, which means propane in liquid form weighs about half as much as water. The specific gravity of a vapor is the comparison of the weight of a given volume of vapor with the same volume of air, m e a s u red at the same temperature and pre s s u re. In Table 4-B, the specific gravity of pr opane vapor is 1.50, which means propane in vapor form is about one and a half times heavier than air. Because propane vapors are he a v i e r , they initially may sink rather than rise when a leak develops and tend to settle to low areas or travel along floors. Theref o r e, open flames, or other potential sources of ignition should be eliminated f rom garages or shops where gasoline or propane powere d vehicles are parked or serviced. 4-10 Ho w e v e r , if there is any circu l a t i o n of air in the area of the rel e a s e , VAPOR pr opane vapor will disperse evenly. PRESSURE BOILING POINT, TEMPERATURE AND PRESSURE LIQUID One of propane’s most important physical properties, and one which 4-9 distinguishes it from gasoline and diesel fuel, is its low boiling point. Courtesy of N.P.G.A. At standard atmospheric pres s u r e 4-3 Pr opane inside a sealed tank (sea level) pure propane boils will remain a liquid as long as the (vaporizes) at -44 o F (-42o C). Pure pre s s u r e is maintained. pr opane is a liquid below -44 o F (- 4 2 o C). At temperatures above -44 o F (-42o C), propane will be a vapor unless it is held under pres s u r e, as in a container. High grade motor quality (HD-5) LPG, a blend of propane, butane, ethane and pr opene, has a typical boiling point of about -50o F (-46o C) . If propane is compressed so that its vapor pres s u r e or tendency to tu r n from a liquid into a vapor is equalized, it will remain a liquid. Table 4-B shows the vapor pre s s u re of propane at diff e re n t

Liquefied Petroleum Gas Training Program PAGE 4-4 Liquefied Petroleum MODULE 4: PRINCIPLES AND PROPERTIES – FUEL THEORY Gas te m p e r a t u r es. As you can see, the amount of pres s u r e req u i r ed to Key Points & Notes keep propane liquid increases with temperature. At -20 o F, for example, very little pres s u r e (only 10.7 psig) is req u i r ed because the te m p e r a t u r e is fairly close to propane’s natural boiling point of -44 o F. At 100o F, however, the pres s u r e req u i r ed increases (196 psig) because the fuel is far above its normal boiling point. If liquid or vapor propane is removed from a container, the pressure in the container is reduced temporarily, causing the liquid propane to vaporize to fill the empty (non-liquid) space with vapor. The vaporization continues until a state of equilibrium between the liquid and vapor in the container is reached at ambient temperature. When liquid is added to the container, the rising liquid compresses the gas in the vapor space, thus increasing the pressure in the container; and the propane vapor begins condensing to propane liquid in order to restore equilibrium at that temperature.

LOW HIGH 4-11

4-4 Propane tanks are filled to 80 perc e n t capacity to allow for thermal expansion. The 80 percent 90 percent left tank illustrates cool t e m p e r a t u res; by late afternoon, high temper- a t u res have caused 80 DEGREES F. 90 DEGREES F. expansion to 90 percent capacity. Co u r tesy of N.P.G . A .

Decreasing temperature will lower the vapor pressure inside a closed fuel tank, just as increasing temperature will raise the pressure. Therefore, a constant balance of temperature and pressure must be maintained. Weather can have a great impact on tank pressure. Hot days, cool nights, direct sunlight, rain, or snow all affect the temperature of the fuel inside the tank and thus the vapor pressure. It is not unusual to see tank pressures change as much as 50 psi in the course of a day.

EXPANSION RATIO Propane, like any other liquid, expands when heated, and it expands very rapidly. Compared to water, propane will expand 17 4-12 times more in volume with an identical increase in temperature. The reason for storing propane under pressure as a liquid inside a fuel tank is to save space. A given volume of propane vapor can be co m p re s s e d into 1/2 7 0 t h of its volume when liquefied. Conversely, a given volume of propane liquid can expand roughly 270 times if allowed to change back into a vapor. Refer to Figure 4.5.

Liquefied Petroleum Gas Training Program PAGE 4-5 Liquefied Petroleum MODULE 4: PRINCIPLES AND PROPERTIES – FUEL THEORY Gas

Key Points & Notes

1 UNIT 4-13 AS LIQUID

VAPORIZATION

1 UNIT AS VAPOR Courtesy of NPGA 270 TIMES LARGER 4- 5 Pr opane has a 1:270 expansion ratio from the liquid to gaseous state.

Because of this expansion, propane fuel tanks are never completely filled with liquid. They are filled to approximately 80 percent of capacity to allow room for thermal expansion. Fuel tanks are also equipped with pressure relief valves that vent propane vapor if internal tank pressure exceeds the preset rating of the valve. The valve closes automatically when internal pressure is reduced below this start-to-discharge pressure.

FLAMMABILITY LIMITS A flammability limit is the minimum or maximum percentage of fuel needed in an air-fuel mixture to support combustion. Combustion 4-14 occurs when the correct ratio of air-fuel is ignited by the introduction of heat, including spark ignition and compression. This value is given in both an upper and lower (minimum) limit of flammability. The upper limit is the maximum concentration or percentage of fuel (richest air-fuel mixture) that will support

TOO JUST 4-15 LEAN RIGHT TOO RICH

I D E A L

0% 2.4% 4% 9.6% 25% 100% AIR-FUEL RATIO John Hilgerdt

4-6 Flammability limits of propane are between 2.5% and 9.6%. combustion. Air-fuel mixtures above the upper limit will not burn because there is too much fuel and not enough air. The lower limit is the minimum concentration or percentage of fuel (leanest air-fuel mixture) that will support combustion. Air-fuel mixtures below the lower limit will not burn because there is too much air and not enough fuel. See Figure 4-6 and Table 4-A for fuel flammability limits of propane.

Liquefied Petroleum Gas Training Program PAGE 4-6 Liquefied Petroleum MODULE 4: PRINCIPLES AND PROPERTIES – FUEL THEORY Gas

COMBUSTION AIR-FUEL RATIO Key Points & Notes Although propane vapor will burn in any mixture within its flammability limits, the burning is most complete when there is just 4-16 the right amount of fuel vapor for the available oxygen in the air. The ideal combustion ratio, also referred to as the stoichiometric air-fuel ratio, for propane is 4 percent by volume. This could be a 24:1 mixture – 24 parts of air to every one part of propane vapor. On a weight basis, the ideal combustion ratio is 15.5:1 (15.5 pounds of air for one pound of propane vapor). See Table 4-A for comparisons. If an air-fuel mixture is richer than the ideal ratio, there is insufficient oxygen to completely burn all the fuel, resulting in partial combustion and the formation of carbon monoxide (CO) and excess hydrocarbons (HC) in the exhaust emissions. Fuel economy suffers because excess fuel is being used. Richer mixtures tend to produce more power up to a certain point, but the trade-off is reduced performance and economy, increased exhaust emissions and higher exhaust temperatures. If an air-fuel mixture is too lean, a condition known as lean misfire can sometimes occur inside the engine. Although the mixture may be above the lower flammability limit, it may be too lean for the spark to ignite. This allows unburned fuel vapors to pass through into the exhaust, increasing HC emissions. Perfo r mance is reduced because of the misfire and economy suffers because of the wasted fuel. HISTORY OF LP-GAS AS AN ENGINE FUEL As a engine fuel, LP-gas (liquefied petroleum gas) is about as old as the automobile itself. In the early 1900s, the primary fuels available 4-17 to power automobiles were gasoline and grain alcohol (ethanol). Gasoline rapidly became the overwhelming choice because of its price advantage and widespread availability, even though the refining techniques of the day made it a highly volatile fuel that would evaporate quickly when stored. Dr. Walter Snelling of the U. S. Bureau of Mines began experiments to improve the refining process in hopes of producing a blend of gasoline that would be more stable and less prone to evaporation. Snelling discovered a method of removing the lighter elements from gasoline, which he later identified as being butane and propane. The result was a much improved gasoline motor fuel for automobiles and the birth of the LP-gas industry. Dr. Snelling, working with Frank P. Peterson and Chester and Arthur Keer, also devised methods for liquefying LP-gas. When a practical means of separating butane and propane from crude oil and natural gas was developed, the first LP-powered automobile appeared in the early 1900s. The use of LP-gas as a motor fuel, however, grew slowly. Its uses began with small fleets of taxicabs, delivery trucks, and similar vehicles. Although LP-gas proved to be an economical and practical fuel for some, there was little general interest in it for automotive applications because gasoline was so plentiful and inexpensive. The bulk of propane production went to domestic uses. Liquefied Petroleum Gas Training Program PAGE 4-7 Liquefied Petroleum MODULE 4: PRINCIPLES AND PROPERTIES – FUEL THEORY Gas

CHANGES IN THE FUEL BLEND Key Points & Notes LP-gas fuel has undergone some significant changes. Until World War II, LP-gas engine fuel was primarily butane. The discovery of 4-18 new uses for butane in gasoline blending and the chemical industry, however, resulted in shifting most of the available butane away from automotive fuel use. Thus, propane became the primary component of LP-gas engine fuel. In 1963, Gas Processors Association adopted a specification for propane engine fuel called “ HD-5.” The purpose of standardizing the fuel was to provide a uniform, quality propane, so engines could 4-19 be designed and tuned to deliver the best performance and fuel economy. The specification is in GPA 2140 “Liquefied Petroleum GOOD QUALITY Gas Specifications and Test Methods” published by the Gas PROPANE CONSISTS OF Processors Association, Tulsa, Oklahoma, and as “special duty 0.04% Methane propane” in ASTM D-1835 “Standard Specification for Liquefied 1.17% Ethane Petroleum (LP) Gases,” published by the American Society for 0% Ethylene Testing & Materials, Philadelphia, Pennsylvania. 97.5% Propane 0.66% Propylene The letters “HD” in the specification stand for “Heavy-Duty,” and the 0.68% Iso-Butane number 5 re p resents the maximum allowable percentage of propylene allowed in the fuel. The HD-5 blend also may contain a maximum of 2.5 percent butane and heavier hydrocarbons by liquid volume, with a minimum 90 percent propane. HD-5 must be essentially free from oily residues and other contaminants such as sulfur (less than ten grains per hundred cubic feet). A maximum vapor pressure of 208 psig at 100o F (3 8 o C) effectively limits ethane content. In other words, HD-5 is a special high-quality grade propane designed for vehicular use. As propane continues to evolve as an engine fuel, some areas are developing alternative standards, such as “autogas,” which is used in Europe and Australia. Autogas is approximately 60 percent propane and 40 percent butane. The subsequent changes in properties should not affect engine performance.

OCTANE RATINGS Propane is an ideal engine fuel because it has a higher octane rating than any premium gasoline. This rating indicates a fuel’s 4-20 resistance to autoignition (detonation). Autoignition, also called detonation, occurs when the pressures inside the combustion chamber become too great for the fuel to burn evenly. Instead of a smooth expanding flame front, multiple flame fronts are formed and collide with one another, producing a sharp pinging or spark knock. Severe knock can quickly damage an engine. See Table 4-A for octane ratings of fuels. There are three different ways to rate a fuel’s resistance to detonation: research octane, motor octane, and pump octane. Research octane rating is determined in a laboratory by comparing the fuel’s detonation resistance to that of two known test fuels using a standard test engine: iso-octane (100 octane) highest grade and normal heptane (0 octane) lowest grade. The fuel is assigned a value relative to the ratio of a mixture of iso-octane to heptane that

Liquefied Petroleum Gas Training Program PAGE 4-8 Liquefied Petroleum MODULE 4: PRINCIPLES AND PROPERTIES – FUEL THEORY Gas

Key Points & Notes

THE NORMAL FLAME FRONT SPREADS (A) AND 4-21 CYLINDER PRESSURE B RISES. UNBURNED END A GASES (B) AUTOIGNITE. A SECOND FLAME FRONT SPREADS. WHEN THE TWO FLAME FRONTS COLLIDE, AN AUDIBLE VI B R A TION IS CREATE D . A U T O I G N I T I O N / K N O C K OCCURS AFTER NORMAL SP ARK IGNITION.

4-7 Autoignition (detonation, kn o c k i n g ) results in the equivalent knock resistance. Until recently, the research octane rating was the one primarily used because it LESS SEVERE RESEARCH appears to be the highest of the three rating methods. OC T ANE TESTS LIGHTLY LOAD THE ENGINE AND Motor octane ratings came into use to more accurately describe a PROVIDE COOL AIR AND fuel’s resistance to detonation in the real world. In the motor octane FUEL TO THE INTA K E . test, the test fuel is evaluated in an engine that simulates actual MOTOR OCTANE TESTS driving conditions, resulting in lower octane numbers. ARE MORE DEMANDING, LOADING THE ENGINE AT Pump octane is the actual rating one can expect at the pump. This HIGH SPEED (RPM) is calculated as R + M/2 = P, or the sum of research and motor WHILE INDUCTING A divided by 2 equals pump octane. This gives us average results of: MUCH HOTTER AIR-FUEL MI X T U R E . Regular Unleaded Gasoline = 87 octane Mid-grade Unleaded Gasoline = 89 octane Premium Unleaded Gasoline = 91-93 octane Propane (HD-5) = 100-105 octane The diffe r ence between res e a r ch and motor octane is fuel sensitivity. This affects the limits of compression ratio and load on an engine. Pr opane is a highly sensitive fuel, which must be considered when designing an engine to run on LPG. See Table 4-C. As you can see, propane is an excellent performance fuel, one that can realistically be compared to the highest quality gasolines.

COMBUSTION CHARACTERISTICS As previously described, one of the physical properties that distinguishes propane from gasoline and diesel fuel is the fact that 4-22 propane is a vapor at standard temperature (60o F/16 o C) and atmospheric pressure (one atmosphere or 14.7 psia). Gasoline and diesel fuel are liquids and do not burn well unless vaporized and mixed with oxygen. With gasoline, either a carburetor or fuel-injection system is necessary to create a fine mist of liquid fuel. To complete the

Liquefied Petroleum Gas Training Program PAGE 4-9 Liquefied Petroleum MODULE 4: PRINCIPLES AND PROPERTIES – FUEL THEORY Gas

A METERING: Key Points & Notes I CORRECT PROPORTIONS R OF FUEL AND AIR 4-23

ATOMIZATION: SPRAY OF FINE PARTICLES, GREAT AIR CONTACT

DISTRIBUTION: UNIFORM MIXTURE DELIVERED TO MANIFOLD

Courtesy of OTC 4-8 Fuel must be completely vaporized for efficient combustion: gasoline enters as tiny droplets of liquid (venturi principle – gasoline carb shown). vaporization process, however, the fuel must pick up additional heat from the engine as it passes through the intake manifold and enters the combustion chamber. Compressing the fuel helps to mix and vaporize the remaining droplets of gasoline. If gasoline isn’t completely vaporized, inefficient combustion causes higher exhaust emissions and reduced fuel economy and performance. Therefore, gasoline engines require a variety of strategies to aid cold-starting. Refer to Figure 4-8. With diesel engines, the situation is somewhat diffe r ent. Diesel fuel is mixed with air by injecting it directly into the combustion chamber or prechamber as a highly pressurized mist. The fuel isn’t injected until the air inside the combustion chamber has been compres s e d and is extremely hot (around 1000o F/ 53 8 o C) . This happens a few de g r ees before top dead center on the compression stroke. The instant the diesel fuel hits the hot air, it ignites. But because there is little time for the air and fuel to mix, diesel combustion is incomplete; as a result, diesels can sometimes emit a lot of soot and other pollutants in their exhaust. For cold starting, a diesel engine must be cranked fast enough to heat the air inside the cylinders to a point where it will ignite the fuel. A glow plug system is req u i re d on many engines to provide the initial starting heat. Lighter grade diesel fuel must also be used during cold weather to prevent waxing and clogging of the fuel lines and injectors. In contrast, propane has excellent cold-start properties because it enters the engine as a vapor at temperatures as cold as -40o F. This eliminates the need for cold-starting aids and allows the fuel to mix readily with air for efficient and clean combustion. Because prop a n e is already in a gaseous state, the fuel mixer’s job is simple compared to that of a gasoline carburet o r , fuel-injection system, or diesel injection system. The mixer delivers the correctly metered amount of propane necessary to maintain the optimum air-fuel ratio. EMISSIONS Another area where propane can reduce pollution is in evaporative emissions. All internal combustion engines produce emissions, but 4-24

Liquefied Petroleum Gas Training Program PAGE 4-10 Liquefied Petroleum MODULE 4: PRINCIPLES AND PROPERTIES – FUEL THEORY Gas some fuels produce less than others. There are four main offenders Key Points & Notes in engine exhaust: hydrocarbons (HCs), carbon monoxide (CO), carbon dioxide (CO2) and various nitrogen oxides (NOx). See Module 7 for a more complete discussion of exhaust emissions All late model passenger cars, and most light- and medium-duty trucks, have charcoal canisters (vapor canisters) to trap evaporative emissions from the gasoline fuel tank. These vapors are drawn into the engine and burned when the engine is started. Although this system does absorb much of the fuel vapors, a saturated canister will still release raw HCs into the atmosphere. Studies indicate that HCs may account for as much as 20 percent of total vehicle emissions. Propane fuel systems produce fewer evaporative emissions because the system is sealed to maintain pressure. A charcoal canister isn’t needed!

ENGINE PERFORMANCE Depending on the engine type and the fuel system, engines converted to run on propane are capable of perfo r ming better than those that 4-25 run on gasoline because a gaseous fuel mixes more readily with air. Depending on the type of air-fuel mixer used, cylinder fuel distribution can be improved for better perfo r mance. In a carburet e d or central-point fuel injected V8, for example, the four cylinders that ar e farthest from the carburetor sometimes run leaner than the four cylinders closest to the carburet o r . Twists and turns in the intake manifold cause the tiny droplets of gasoline to separate from the air- fuel mixture as it flows through the manifold. This creates rich and lean regions that can upset the power balance of the engine. Prop a n e

AIR IN 4-26

GAS (VAPOR) FUEL IN

Courtesy of IMPCO 4-9 Fuel must be completely vaporized for efficient combustion. Prop a n e enters the engine as a vapor (air valve mixer schematic shown).

Liquefied Petroleum Gas Training Program PAGE 4-11 Liquefied Petroleum MODULE 4: PRINCIPLES AND PROPERTIES – FUEL THEORY Gas can improve fuel distribution because it is a gas. There are no heavy Key Points & Notes dr oplets of fuel to be carried through intake runners, which makes fuel separation less of a problem. Refer to Figure 4-9. Also, as mentioned before, propane has a higher octane rating than gasoline, which allows the engine to use a more advanced ignition timing curve at lower rpm and still resist detonation. Advancing the timing can improve low-speed torque so propane-fueled engines with modified ignition timing curves usually run smoother and have more low-end pulling power. However, it is important to note that modifications to ignition systems are illegal in some areas. Another factor that contributes to increased perfo r mance is a denser ai r -fuel mixture entering the cylinders. Preheating the intake manifold is necessary on some gasoline engines to help vaporize the fuel. But because propane is already vaporized when it enters the intake manifold, heating is not necessary or desirable. Lower intake te m p e r a t u r es promote a denser mixture for more power. Engines can be designed and optimized to run on propane by raising co m p r ession, modifying valves and seals, and improving air-f u e l mi x t u r e. It is important to note, however, that high perfo rm a n c e pr opane engines are diffe r ent than their gasoline counterparts. Note: High perfo r mance gasoline engine components may not work well on prop a n e .

ENGINE MAINTENANCE AND LIFE Clean combustion also promotes longer spark plug life, decrea s e d valve train wear, and reduced internal engine component wear, thus 4-27 extending engine life and reducing maintenance costs. For a fleet operating vehicles with long chassis and body lives, propane can considerably reduce maintenance costs by extending component life. Propane’s clean-burning characteristics practically eliminate the buildup of carbon, varnish, and sludge inside the engine. Fewer contaminants in the crankcase means that oil change intervals may be safely extended. Oil is an engine’s lifeblood. When sludge and acid build up as a result of combustion blow-by, the additives in the oil are rapidly used up. The bearings, rings, valve guides, cam lobes, and other friction su r faces begin to suffer as the lubricant breaks down. Because pr opane burns cleaner than gasoline, especially during engine wa r m-up, there are practically no contaminants that find their way into the crankcase. Engine life, as a result, is much extended. Specially formulated motor oils for propane-powered engines are available with additive packages tailored to the unique needs of the engine. The additives that are used in regular motor oils to disperse acids and varnish are not necessary in a propane-powered engine; in fact, they can form harmful deposits on the valves. Propane engine oils also contain additives that prevent the oil viscosity from changing or thickening when extended change intervals are used. However, in dual-fuel application, oils designed for propane service are not recommended.

Liquefied Petroleum Gas Training Program PAGE 4-12 Liquefied Petroleum MODULE 4: PRINCIPLES AND PROPERTIES – FUEL THEORY Gas

SAFETY CONSIDERATIONS FOR LPG Key Points & Notes Over the past six decades, LPG has been proven to be a safe fuel for consumer use. However, as with all fuels, special safety 4-28 precautions must be taken. LPG is stored as a liquid under pressure and when it is exposed to air it vaporizes. During the vaporization process, LPG extracts heat from the surrounding air and anything in that air. Therefore, gloves should be worn when refueling because skin contact with LPG an cause frostbite. LPG is a nontoxic gas. High concentrations of LPG reduce oxygen levels that can cause asphyxiation, with early symptoms of dizziness. No harmful long-term effects have been reported from exposure to propane vapors. An odorant added to LPG generally enables its detection by humans at concentrations below the lower flammability limit and much below the concentrations causing asphyxiation. Storage and maintenance facilities must be designed to include ventilation. Fuel tanks certified by the American Society of Mechanical Engineers (ASME) are used to store LPG under pressure in LPG-fueled vehicles. As with all fuel tanks, the possibility of LPG tank explosions does exist under extreme conditions. These conditions are present when high vaporization rates build pressure faster than the pressure relief system can lower it (e.g., fire engulfs the tank), or pressure relief equipment is not functional (e.g., the tank is physically rolled over such that liquid rather than vapors is vented through the relief system). LPG tanks are safe because of the many safety features designed into them including the following: • LPG tanks are designed and built to withstand 1000 psi even though normal LPG operating pressures are only 130 to 170 psi. As a result, LPG tanks are less likely to rupture than conventional gasoline tanks. • LPG tanks are designed to be filled to only 80 percent capacity to allow for gas expansion because of temperature increase. • LPG tank ruptures from external damage are not likely to result in an explosion because tank pressure will be vented at the rupture point. • Ignition inside a tank is highly unlikely because no oxygen is present. ORIGINS OF LPG LPG is a natural derivative of both natural gas and crude oil. In the U.S., approximately 45 percent of LPG is from oil refining and 55 4-29 percent is from natural gas processing and reserves. Domestic production accounts for over 85 percent of the LPG supply. Motor fuel grade LPG is currently available at over 10,000 fueling stations, LPG dealers, and from some truck stops.

Liquefied Petroleum Gas Training Program PAGE 4-13 Liquefied Petroleum MODULE 4: PRINCIPLES AND PROPERTIES – FUEL THEORY Gas

AVAILABILITY OF LPG AND THE CHARACTERISTICS OF ITS Key Points & Notes INFRASTRUCTURE The U.S. is the world’s largest producer of LPG and currently supplies 85 percent of its LPG demand from domestic resources; the 4-30 remaining 15 percent is imported. Canada produces an excess of Fuel Facts: Propane LPG, which is exported to the U.S. via pipelines. It is estimated that Supply and Demand an additional 1 billion gallons of LPG could be available annually from new Canadian natural gas development, and worldwide as much as 10 billion gallons more of LPG could be available on an annual basis from new natural gas developments. Th e r e are over 10,000 motor fuel refueling stations for LPG curren t l y in use. Theref o r e, the switch from gasoline to LPG as a motor fuel can be accomplished in public and private fleets with relative ease. A common perception is that LPG is not available in suffi c i e n t quantities to play a major long term role in transportation. The LPG industry believes that the domestic LPG supply is sufficient to economically supply 21 million vehicles in 2005, or 12.5 percent of U.S. automobiles. Projections by the California Energy Commission indicate that LPG can be expected to remain affo r dably priced in the near future. Supplies are not anticipated to be a problem, and pr opane proponents suggest that stable LPG supplies can be assured fr om switching propane from its use as a feedstock to use as a motor fuel and by expanding the production of LPG from natural gas. WORLD VIEW ON LPG AND WHO IS USING LPG VEHICLES Public indifference to alternative fuels changed with the Arab Oil Embargo in 1973. Suddenly, gasoline was in uncertain supply and 4-31 expensive. In response to rapidly increasing fuel prices, interest in propane as an alternative to gasoline rose sharply, and a rapid growth spurt in LP-gas fuel conversions occurred in the late 1970s and early 1980s. By 1978 the number of vehicles being converted to propane was about 35,000 per year. As the price of gasoline climbed to a dollar-a-gallon mark in 1981, the number of vehicles being converted to propane jumped to nearly 250,000. Those who switched found the cost of conversion often paid for itself within a year or less, depending on the number of miles driven. In 1989, there were close to 4 million propane-powered vehicles worldwide. Countries in which LPG is the most commonly used fuel are Italy (over 800,000 vehicles) and the Netherlands (over 500,000 vehicles). Other countries that have promoted the use of LPG vehicles include Spain, Canada, and Australia. LPG AS A MOTOR FUEL As with any fuel, LPG has both advantages and disadvantages which can best be evaluated in comparison to gasoline.

ADVANTAGES OF LPG: 1. Propane leaves no lead, varnish, or carbon deposits. It doesn’t scour the cylinders or wash oil off the walls as liquid fuels do. 4-32

Liquefied Petroleum Gas Training Program PAGE 4-14 Liquefied Petroleum MODULE 4: PRINCIPLES AND PROPERTIES – FUEL THEORY Gas

This means less friction and wear on cylinders, pistons, and Key Points & Notes rings. If the fuel system is properly adjusted, valve and spark plug life can be extended. Propane also contaminates the crankcase or combustion chamber of the engine much less than gasoline. A clean engine lowers maintenance costs, reduces downtime, and extends engine life. 2. The United States has large resources of LPG that can help reduce dependence on foreign oil. 3. Propane is self-pressurized so a fuel pump is not necessary. This decreases repair and replacement costs. 4. The mixer on a propane fueled engine is a simple mechanism with few moving parts and no atmosphere vents to allow troublesome dirt to be drawn in. 5. P ropane fueled engines that are designed for pro p a n e combustion can produce more horsepower per cubic inch piston displacement than a diesel engine of the same weight and displacement. Propane engines can be run very lean. Fuel savings can be a major factor in the propane engine fuel. They result from consistent quality, improved efficiency, and no evaporation or spillage. 6. LPG as a motor fuel has an excellent safety record.

DISADVANTAGES OF LPG VEHICLES:

1. Added weight from the fuel tank(s), ranging between 25 pounds to 275 pounds per tank, may reduce efficiency and load carrying 4-33 capacity. 2. Size and location of the fuel tank(s) may reduce cargo space. 3. Some locations have few fueling stations. 4. Conversion costs are generally between $1,500 and $2,500; the major cost is the high-pressure fuel tank. 5. On a bi-fuel vehicle, the engine cannot be optimized for both fuels, so performance is reduced. 6. Power loss resulting from the displacement of engine air is typically 9.4 percent. However, some engines lose 20 percent power. (The average driver may not be aware of this power loss under normal driving conditions.) 7. Converted engines were designed for their primary fuel – gasoline. Because LPG is gaseous and because it runs through a different fuel system, problems may arise in the gasoline engine such as valve recession, computer malfunctions and excessive emissions. 8. Because energy density of propane is less than that of gasoline, more space for fuel is required to equal range of the same vehicle operating on gasoline.

Liquefied Petroleum Gas Training Program PAGE 4-15 Liquefied Petroleum MODULE 4: PRINCIPLES AND PROPERTIES – FUEL THEORY Gas

WHY FLEET OPERATORS SHOULD BE INTERESTED IN LPG Key Points & Notes VEHICLES Urban fleet vehicles are the best candidates for LPG conversions for several reasons: 4-34 • Most fleets have centrally located fueling facilities. • Fleet vehicles normally travel short driving ranges. • Driving patterns usually are predictable, so a fueling schedule can be maintained. • Fleets usually contain trucks and vans that have adequate space and suspension weight capacity for additional fuel storage. • Fleet vehicles generally travel more miles than private vehicles, allowing the investment to be recovered sooner. Some estimates indicate a fleet should have between 25 and 50 vehicles to recover investment over an acceptable period. The most optimistic estimates claim a fleet of 2 vehicles can recover its investment in under 1 year. Depending on the number of miles a vehicle travels, 1 to 4 years are needed to recover the costs of converting a vehicle to LPG. Conversions will become less common as OEMs build more dedicated and bi-fuel propane vehicles. There are many reasons for fleets to convert their vehicles to LPG vehicles. Substantial savings can be realized from inexpensive fuel and reduced maintenance. Reducing pollutants in the environment is an important long-term benefit. Energy security is important to the United States’ economic competitiveness. Conversion also can improve a fleet’s public image. Considering the many existing and proposed federal mandates for fleets to convert to clean fuel technologies, converting now will give fleet managers time to evaluate LPG technology before being re q u i red to implement alternative fuels.

Liquefied Petroleum Gas Training Program PAGE 4-16 Liquefied Petroleum MODULE 4: PRINCIPLES AND PROPERTIES – FUEL THEORY Gas

Liquefied Petroleum Gas Training Program PAGE 4-17 Liquefied Petroleum MODULE 4: PRINCIPLES AND PROPERTIES – FUEL THEORY Gas

PHYSICAL PROPERTIES OF PROPANE (English)

Chemical Formula C3H8 -44O F 0 psig -20O F 10.7 psig 70O F 127 psig 100O F 196 psig 105O F 210 psig 130O F 287 psig Specific gravity of liquid at 60O F 0.504 Initial boiling point at 14.7 psia O F -44 Weight per liquid gallon at 60O F 4.20 Specific heat of liquid, Btu/lb at 60O F 0.63 Cu ft of vapor per gallon at 60O F 36.38 Cu ft of vapor per pound at 60O F 8.66 Specific gravity/vapor (air=1) 60O F 1.50 Ignition Temperature in air, O F 920-1120 Maximum flame temp in air, O F 3595 Limits of flammability in air, % of vapor in air-gas mixture (a) Lower 2.15 (b) Upper 9.60 Latent heat of vaporization at boiling point (a) Btu per pound 184 (b) Btu per gallon 773 Total heating values after vaporization (a) Btu per cubic foot 2,488 (b) Btu per pound 21,548 (c) Btu per gallon 91,502 Octane ratings Research 110 Motor 95 Pump 103

Table 4-B (English)

Liquefied Petroleum Gas Training Program PAGE 4-18 Liquefied Petroleum MODULE 4: PRINCIPLES AND PROPERTIES – FUEL THEORY Gas

PHYSICAL PROPERTIES OF PROPANE (Metric)

Chemical Formula C3H8 20O C 895 Kpa 40O C 1482 Kpa 45O C 1672 Kpa 55O C 1980 Kpa Specific gravity of liquid at 15.56O C 0.504 Initial boiling point at 1.00 Atm.O C -42 Weight per cubic metre of liquid at 15.56O C, kg 504 Specific heat of liquid, Kilojoule per kilogram, at 15.56O C 1464 Cubic metre of vapor per litre of liquid at 15.56O C 0.271 Cubic metre of vapor per kilogram of liquid at 15.56O C 0.539 Specific gravity of vapor (air=1) at 15.56O C 1.50 Ignition Temperature in air, O C 493-549 Maximum flame temp in air, OC 1980 Limits of flammability in air, % of vapor in air-gas mixture (a) Lower 2.15 (b) Upper 9.60 Latent heat of vaporization at boiling point (a) Kilojoule per kilogram 428 (b) Kilojoule per litre 216 Total heating values after vaporization (a) Kilojoule per cubic metre 92,430 (b) Kilojoule per litre 25,140 (c) Kilojoule per kilogram 49,920

Table 4-B (Metric)

Liquefied Petroleum Gas Training Program PAGE 4-19 Liquefied Petroleum MODULE 4: PRINCIPLES AND PROPERTIES – FUEL THEORY Gas

OCTANE NUMBERS OF POSSIBLE NG AND LPG COMPONENTS Research Motor Sensitivity* Methane 132 128 4.0 (Low sensitivity) Propane 111.4 97.1 14.3 n-Butane 94.0 89.1 4.9 Propylene 101.8 84.9 16.9 (High sensitivity) Ethane 111.5 100.7 10.8 Iso-Butane 102.1 97.6 4.5 Iso-Pentane 93.0 89.7 3.3 LP-GAS TEST BLENDS A B Research** Motor** Sensitivity 90% Propane + 10% n-Butane*** 109.7 96.3 13.4 75% Propane + 25% n-Butane 107.1 95.1 12 60% Propane + 40% n-Butane 104.4 93.9 10.5 50% Propane + 50% n-Butane 102.7 93.1 9.6 40% Propane + 60% n-Butane 101.0 92.3 8.7 92% Propane + 8% Propylene 110.6 96.1 14.5 80% Propane + 20% Propylene 109.5 94.7 14.8 53% Propane + 47% Propylene 106.9 91.4 15.5

*Sensitivity – Difference between research and motor octane **Octane numbers calculated from components as follows: (Liq. Vol. % of A) (O.N. of A) + (Liq. Vol. % of B) (O.N. of B) = O.N. of Blend 100 ***All percentages referred to in this table are liquid volume percent Table 4-C Octane numbers of possible NG and LPG components.

Liquefied Petroleum Gas Training Program PAGE 4-20 Liquefied Petroleum MODULE 4: PRINCIPLES AND PROPERTIES – FUEL THEORY Gas

Key Points & Notes

Liquefied Petroleum Gas Training Program PAGE 4-21 Liquefied Petroleum MODULE 4: PRINCIPLES AND PROPERTIES – FUEL THEORY Gas

MODULE REVIEW ITEMS

Note to Technician: Consider all choices carefully and select the best answer to each. 1. Propane, gasoline, and diesel fuel are all members of what family? A. Hydrogen. B. Hydrocarbon. C. Heptane. D. Gasoline.

2. What gives each fuel its set of physical properties? A. The weight of its hydrogen and carbon atoms. B. The size of its hydrogen and carbon atoms. C. The number and arrangement of its hydrogen and carbon atoms. D. None of the above.

3. At atmospheric pressure, why are some fuels found in a gaseous state? A. Their molecules have a low molecular weight. B. Their molecules are large. C. Their molecules have a high molecular weight. D. B & C.

4. Which fuels are not a liquid at standard atmospheric pressure? A. Gasoline and ethanol. B. Kerosene and methane. C. Propane and butane. D. Diesel fuel and ethane.

5. What percentage of propane does LPG, used as commercial fuel, need to consist of? A. 75%. B. 85%. C. 95%. D. 100%.

6. The heat value of LPG is the total BTUs contained in the fuel. A. True. B. False.

7. What is heat of vaporization? A. The amount of heat needed to convert propane into steam. B. The amount of heat lost in vaporization. C. The amount of heat needed to convert the water in a fuel into steam. D. None of the above.

8. The greater the number of carbon atoms in a molecule the _____ the heat content or energy value of the fuel. A. Lower. B. Greater. C. Equal. D. None of the above.

Liquefied Petroleum Gas Training Program PAGE 4-22 Liquefied Petroleum MODULE 4: PRINCIPLES AND PROPERTIES – FUEL THEORY Gas

9. It takes less propane to achieve the same power output as gasoline. A. True. B. False.

10. Propane in liquid state weighs about _____ an equal amount of water. A. The same as. B. 2 times more than. C. 1/2 less than. D. None of the above.

11. Propane in a vapor state weighs about _____ an equal amount of air? A. 1/2 less than. B. The same as. C. 1 times more than. D. 1 and 1/2 times more than.

12. Based upon your answer above, why is this a safety concern? A. Propane vapors may ignite. B. Propane vapors may sink rather than rise. C. Propane vapors may rise rather than sink. D. None of the above.

13. What state will propane be in at temperatures below -440oF (at standard atmospheric pressure)? A. Vapor. B. Liquid. C. Solid. D. None of the above.

14. At temperatures above -440oF (at standard atmospheric pressure), what state will propane exist as? A. Vapor. B. Liquid. C. Solid. D. None of the above.

15. The amount of pressure required to keep propane in its liquid form _____ with temperature. A. Increases. B. Decreases. C. Remains equal. D. None of the above.

16. Why are propane fuel tanks only filled to 80% capacity? A. To allow for thermal expansion. B. So ambient temperature can be reached. C. To allow for the heat of vaporization. D. All of the above.

17. What is the stoichiometric air/fuel ratio for propane? A. 24 parts of air to every one part of propane vapor. B. 4% by volume. C. The ideal combustion ratio. D. All of the above.

Liquefied Petroleum Gas Training Program PAGE 4-23 Liquefied Petroleum MODULE 4: PRINCIPLES AND PROPERTIES – FUEL THEORY Gas

18. If an air/fuel mixture is richer than the ideal ratio, there is _____ oxygen. A. Insufficient. B. Excess. C. An equal amount of. D. None of the above.

19. Why was there little interest in LPG as an automotive fuel in the early 1900s? A. Gasoline was cheaper and more abundant. B. The bulk of propane went to industrial use. C. It was not practical to separate propane from crude oil. D. Propane was too volatile.

20. HD-5 is known for what? A. Designing engines for best performance. B. Autogas development in Europe. C. Being a high quality 60% propane and 40% butane mixture. D. Being free of oil residue.

21. Octane rating refers to a fuel's resistance to detonation. A. True. B. False.

22. How can engines be optimized to run on propane? A. Increasing compression. B. Modifying valves and seals. C. Improving air/fuel mixture. D. All of the above.

23. What does clean combustion promote? A. Longer spark plug life. B. Decreased valve train wear. C. Reduced internal combustion wear. D. All of the above.

24. Approximately how many propane vehicles are there worldwide? A. 500,000. B. 800,000. C. 2 million. D. 4 million.

25. Which is not a disadvantage of LPG vehicles? A. A tank weight of 25 to 275 pounds. B. Bi-fuel vehicles can not be optimized for both fuels. C. The energy density of LPG is less than that of gasoline, therefore more fuel storage space is required. D. The average driver is immediately aware of the 20% power loss from LPG.

26. Why are fleet vehicles the best candidates for conversion? A. They can improve their public image by reducing pollutants. B. Fleets lack central fueling points. C. Fleet vehicles drive long distances. D. Their maintenance requirements are more expensive.

Liquefied Petroleum Gas Training Program

PAGE 4-25 Liquefied Petroleum MODULE 4: PRINCIPLES AND PROPERTIES – FUEL THEORY Gas

MRI SCORING KEY

1. B 2. C 3. A 4. C 5. C 6. A 7. C 8. B 9. B 10. C 11. D 12. B 13. B 14. A 15. A 16. A 17. D 18. A 19. A 20. D 21. A 22. D 23. D 24. D 25. D 26. A

Liquefied Petroleum Gas Training Program

1 MODULE 4: Principles and Properties - Fuel Theory 2 PHYSICAL CHARACTERISTICS & PROPERTIES OF ENGINE FUELS • Hydrocarbon family

• Propane- C3H8

• Butane- C4H10 • Gas at regular atmosphere 3 4-1 HYDROCARBON MOLECULES 4 HIGH AND LOW HEAT VALUES • High heat value • Low heat value • Heat of vaporization • HHV of propane = 21650 Btus • LHV of propane = 19920 Btus 5 HEAT CONTENT • # Carbon atoms vs. Btus • Weight vs. Btu • Engine horsepower output • Tables 4-A & 4-B 6 ODORANT • Ethyl Mercaptan added • Ratio- 10,000gal. LPG:1 pint odorant 7 SPECIFIC GRAVITY AND DENSITY • Specific gravity • Propane (liquid)- .504 (lighter than water) • Propane (gas)- 1.5 (heavier than air) • Table 4-B 8 4-2 SPECIFIC GRAVITY

9 BOILING POINT, TEMPERATURE AND PRESSURE • LPG has a low boiling point – Below -440 F, propane exist as a liquid – Above -440 F, propane will be a vapor unless it is held under pressure – The amount of pressure required to the keep propane in its liquid form increases with temperature • Climate, environmental effects on LPG in tanks 10 4-3 PROPANE PRESSURE 11 4-4 THERMAL EXPANSION 12 EXPANSION RATIO • 17 times more expansion in volume than water • Compression into 1/270 of its volume • 80% capacity limit in storage 13 4-5 EXPANSION RATIO 14 4-6 FLAMMABILITY LIMITS • Fuel % in air/fuel mixture needed for combustion • Mixtures above or below % range will not ignite 15 4-6 FLAMMABILITY LIMITS

16 COMBUSTION AIR/FUEL RATIO • Stoichiometric air/fuel ratio- ideal combustion ratio • LPG 4%:Air 96% by volume • LPG 1.0 lbs.:Air 15.8 lbs. by weight • Rich mixtures= insufficient oxygen • Lean mixtures= too much oxygen • Table 4-A 17 HISTORY OF LP-GAS AS AN ENGINE FUEL • Gasoline early popular choice because of wide availability • Dr. Walter Snelling isolated butane and propane • Created LPG with Frank Peterson and Arthur Keer • Slow LPG growth in transportation field • Primary domestic uses 18 CHANGES IN THE FUEL BLEND • Shift away from butane as engine fuel • HD-5 specifications • 90% propane, 2.5% butane • Autogas specifications • 60% propane, 40% butane 19 GOOD QUALITY PROPANE • 0.04% Methane • 1.17% Ethane • 0.00% Ethylene • 97.5% Propane • 0.66% Propylene • 0.68% Iso-Butane 20 OCTANE RATINGS • Octane • Detonation • Research octane • Motor octane • Pump octane • LPG: 100-105 octane • Table 4-A & 4-C 21 4-7 AUTOIGNITION 22 COMBUSTION CHARACTERISTICS • Gasoline engines • Diesel engines • LPG engines 23 4-8 COMBUSTION AIR/FUEL RATIO 24 EMISSIONS • 4 main offenders of engine exhaust: – Hydrocarbons (HCs) – Carbon Monoxide (CO)

– Carbon Dioxide (CO2)

– Nitrogen Oxides (NOx) 25 ENGINE PERFORMANCE • Improved fuel distribution • More aggressive ignition timing • Low-speed torque • More low-end pulling power • Denser air/fuel mixture 26 4-9 EFFICIENT COMBUSTION 27 ENGINE MAINTENANCE AND LIFE • Longer spark plug life • Decreased valve train wear • Reduced internal engine component wear • Extends engine life and reduce maintenance costs • Elimination the buildup of carbon, varnish and sludge inside the engine • Few contaminants in the crankcase 28 SAFETY CHARACTERISTICS OF LPG • Cold when under pressure • Non-toxic but avoid inhaling • Fuel tank considerations 29 ORIGINS OF LPG • Derivative of natural gas and crude oil • US produces 85% of LPG supply • Motor grade LPG at 10000 supply stations 30 AVAILABILITY OF LPG AND THE CHARACTERISTICS OF ITS INFRASTRUCTURE • US is the world’s largest producer of LPG • LPG quantities available to supply 21 million vehicles in 2005 (12.5% of U.S. automobiles) • Move to expand motor fuel use of LPG 31 WORLD VIEW ON LPG AND WHO IS USING LPG VEHICLES • 1973 Arab Oil Embargo • 250,000 conversions per year in 1981 • 4 million propane powered vehicles in 1989 • 4 million LPG vehicles worldwide • 800,000 in Italy; 500,000 in the Netherlands 32 ADVANTAGES OF LPG • Lower maintenance costs, reduces downtime, and extends engine life • US has large resources of LPG • Fuel pump is not necessary • The carburetor is simple with few moving parts • Fuel savings • Excellent safety record • Reduces pollutants in the environment 33 DISADVANTAGES OF LPG VEHICLES • Added weight from the fuel tank(s) • Possible reduction in cargo space • Some locations have few fueling stations • On a bi-fuel vehicle, the engine cannot be optimized for both fuels • Power loss • More space for fuel is required to equal range of the same vehicle operating on gasoline 34 WHY FLEET OPERATORS SHOULD BE INTERESTED IN LPG VEHICLES • Urban Fleet Vehicles are the best candidates for LPG conversion: – Centrally located fueling facilities – Short driving ranges – Driving patterns are predictable – Adequate space and suspension weight capacity for additional fuel storage – Investment can be recovered sooner – Reducing pollutants in the atmosphere MODULE 4: Principles and Properties - Fuel Theory

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 4-1

PHYSICAL CHARACTERISTICS & PROPERTIES OF ENGINE FUELS

• Hydrocarbon family

• Propane- C3H8

• Butane- C4H10 • Gas at regular atmosphere

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 4-2

4-1 HYDROCARBON MOLECULES

John Hilgerdt

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 4-3

HIGH AND LOW HEAT VALUES

• High heat value • Low heat value • Heat of vaporization • HHV of propane = 21650 Btus • LHV of propane = 19920 Btus

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 4-4

HEAT CONTENT

• # Carbon atoms vs. Btus • Weight vs. Btu • Engine horsepower output • Tables 4-A & 4-B

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 4-5

ODORANT

• Ethyl Mercaptan added • Ratio- 10,000gal. LPG:1 pint odorant

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 4-6

SPECIFIC GRAVITY AND DENSITY

• Specific gravity • Propane (liquid)- .504 (lighter than water) • Propane (gas)- 1.5 (heavier than air) • Table 4-B

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 4-7

4-2 SPECIFIC GRAVITY

Courtesy of NPGA

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 4-8

BOILING POINT, TEMPERATURE AND PRESSURE

• LPG has a low boiling point – Below -440 F, propane exist as a liquid – Above -440 F, propane will be a vapor unless it is held under pressure – The amount of pressure required to the keep propane in its liquid form increases with temperature • Climate, environmental effects on LPG in tanks

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 4-9

4-3 PROPANE PRESSURE

Courtesy of NPGA

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 4-10

4-4 THERMAL EXPANSION

Courtesy of NPGA

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 4-11

EXPANSION RATIO

• 17 times more expansion in volume than water • Compression into 1/270 of its volume • 80% capacity limit in storage

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 4-12

4-5 EXPANSION RATIO

Courtesy of NPGA

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 4-13

4-6 FLAMMABILITY LIMITS

• Fuel % in air/fuel mixture needed for combustion • Mixtures above or below % range will not ignite

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 4-14

4-6 FLAMMABILITY LIMITS

TOO JUST TOO LEAN RIGHT RICH

I D E A L 0% 2.4% 4% 9.6% 25% 100%

AIR-FUEL RATIO

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 4-15

COMBUSTION AIR/FUEL RATIO

• Stoichiometric air/fuel ratio- ideal combustion ratio • LPG 4%:Air 96% by volume • LPG 1.0 lbs.:Air 15.8 lbs. by weight • Rich mixtures= insufficient oxygen • Lean mixtures= too much oxygen • Table 4-A

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 4-16

HISTORY OF LP-GAS AS AN ENGINE FUEL

• Gasoline early popular choice because of wide availability • Dr. Walter Snelling isolated butane and propane • Created LPG with Frank Peterson and Arthur Keer • Slow LPG growth in transportation field • Primary domestic uses

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 4-17

CHANGES IN THE FUEL BLEND

• Shift away from butane as engine fuel • HD-5 specifications • 90% propane, 2.5% butane • Autogas specifications • 60% propane, 40% butane

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 4-18

GOOD QUALITY PROPANE

• 0.04% Methane • 1.17% Ethane • 0.00% Ethylene • 97.5% Propane • 0.66% Propylene • 0.68% Iso-Butane

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 4-19

OCTANE RATINGS

• Octane • Detonation • Research octane • Motor octane • Pump octane • LPG: 100-105 octane • Table 4-A & 4-C

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 4-20

4-7 AUTOIGNITION

The normal flame front spreads (A) and cylinder pressure rises. Unburned end gases (B) autoignite. A second flame front spreads. When the two flame fronts A B collide, an audible vibration is created. Autoignition/knock occurs after normal spark ignition.

Michele Ortega

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 4-21

COMBUSTION CHARACTERISTICS

• Gasoline engines • Diesel engines • LPG engines

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 4-22

4-8 COMBUSTION AIR/FUEL RATIO

A I R METERING: Correct proportions of fuel and air

ATOMIZATION: Spray of fine particles, great air contact

DISTRIBUTION: Uniform mixture delivered to manifold

Courtesy of OTC

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 4-23

EMISSIONS

• 4 main offenders of engine exhaust: – Hydrocarbons (HCs) – Carbon Monoxide (CO)

– Carbon Dioxide (CO2)

– Nitrogen Oxides (NOx)

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 4-24

ENGINE PERFORMANCE

• Improved fuel distribution • More aggressive ignition timing • Low-speed torque • More low-end pulling power • Denser air/fuel mixture

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 4-25

4-9 EFFICIENT COMBUSTION

AIR IN

GAS (VAPOR) FUEL IN

Courtesy of IMPCO

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ENGINE MAINTENANCE AND LIFE

• Longer spark plug life • Decreased valve train wear • Reduced internal engine component wear • Extends engine life and reduce maintenance costs • Elimination the buildup of carbon, varnish and sludge inside the engine • Few contaminants in the crankcase

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 4-27

SAFETY CHARACTERISTICS OF LPG

• Cold when under pressure • Non-toxic but avoid inhaling • Fuel tank considerations

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 4-28

ORIGINS OF LPG

• Derivative of natural gas and crude oil • US produces 85% of LPG supply • Motor grade LPG at 10000 supply stations

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AVAILABILITY OF LPG AND THE CHARACTERISTICS OF ITS INFRASTRUCTURE

• US is the world’s largest producer of LPG • LPG quantities available to supply 21 million vehicles in 2005 (12.5% of U.S. automobiles) • Move to expand motor fuel use of LPG

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 4-30

WORLD VIEW ON LPG AND WHO IS USING LPG VEHICLES

• 1973 Arab Oil Embargo • 250,000 conversions per year in 1981 • 4 million propane powered vehicles in 1989 • 4 million LPG vehicles worldwide • 800,000 in Italy; 500,000 in the Netherlands

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 4-31

ADVANTAGES OF LPG

• Lower maintenance costs, reduces downtime, and extends engine life • US has large resources of LPG • Fuel pump is not necessary • The carburetor is simple with few moving parts • Fuel savings • Excellent safety record • Reduces pollutants in the environment

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 4-32

DISADVANTAGES OF LPG VEHICLES

• Added weight from the fuel tank(s) • Possible reduction in cargo space • Some locations have few fueling stations • On a bi-fuel vehicle, the engine cannot be optimized for both fuels • Power loss • More space for fuel is required to equal range of the same vehicle operating on gasoline

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 4-33

WHY FLEET OPERATORS SHOULD BE INTERESTED IN LPG VEHICLES

• Urban Fleet Vehicles are the best candidates for LPG conversion: – Centrally located fueling facilities – Short driving ranges – Driving patterns are predictable – Adequate space and suspension weight capacity for additional fuel storage – Investment can be recovered sooner – Reducing pollutants in the atmosphere

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 4-34

MODULE 5: Legislative And Regulatory Policies

State of Oklahoma College of the Desert West Virginia University

Liquefied Petroleum MODULE 5: LEGISLATIVE AND REGULATORY POLICIES Gas

CONTENTS

OBJECTIVES...... 5-i INSTRUCTOR NOTES ...... 5-ii POLLUTION LAWS PERTAINING TO ALTERNATIVE FUEL VEHICLES ...... 5-1 POLICIES IMPLEMENTED THROUGH THE ALTERNATIVE MOTOR FUEL ACT (AMFA)...... 5-1 FEDERAL ENERGY POLICY ACT (FEPA-92)...... 5-2 SUMMARIZED MANDATES OF THE CLEAN AIR ACT AMENDMENTS (CAAA)...... 5-3 THE CALIFORNIA AIR RESOURCE BOARD (CARB)...... 5-3 REGULATIONS ENFORCED BY THE U. S. DEPARTMENT OF TRANSPORTATION (DOT)...... 5-4 NATIONAL FIRE PROTECTION AGENCY (NFPA-58) RULES AND REGULATIONS...... 5-4 PROPANE RELATED AGENCIES...... 5-5 MODULE REVIEW ITEMS...... 5-9 MRI SCORING KEY...... 5-11 ACTIVITY 5-1: INTERNET ACCESS ACTIVITY 5-2: INTERNET SEARCH FOR LEGISLATIVE AND REGULATORY POLICIES OVERHEAD TRANSPARENCY MASTERS

Liquefied Petroleum Gas Training Program

PAGE 5-i Liquefied Petroleum MODULE 5: LEGISLATIVE AND REGULATORY POLICIES Gas

OBJECTIVES

At the completion of this module, the technician will be able to: • Identify pollution laws pertaining to alternative fuel vehicles. • Identify policies implemented through the Alternative Motor Fuel Act (AMFA). • Discuss the Federal Energy Policy Act (FEPA-92). • Summarize mandates by the Clean Air Act Amendments (CAAA). • Discuss Environmental Protection Agency Standards (EPA). • Discuss standards being established through the California Resource Board (CARB). • Discuss regulations enforced by the U. S. Department of Transportation (DOT). • Discuss National Fire Protection Agency (NFPA-58) rules and regulations. • Identify LPG regulatory agencies.

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INSTRUCTOR NOTES

INSTRUCTOR MATERIALS/MEDIA NEEDED Overhead projector or LCD panel/projection equipment Overhead transparency masters or Microsoft PowerPoint 4.0 presentation file Mod5.ppt

Note: Slides correspond to text as indicated by icon:

VCR with TV or projection unit Videotape Segment #2: Clearing the Air, 17 minutes Videotape segment #3: Propane: A Global Market Place, 10.5 minutes

Note: Videotape segments correspond to text as indicated by icon

Laboratory Activities: Activity 5-1: Internet Access Activity 5-2: Internet Search for Legislative and Regulatory Policies

Note: Lab activities correspond to text as indicated by icon

STUDENT MATERIALS/MEDIA NEEDED Module 5: Legislative and Regulatory Policies

OVERHEAD TRANSPARENCY MASTERS The printouts enclosed with this module are taken from the Microsoft PowerPoint 4.0 presentation file Mod5.ppt . Instructors planning to use overhead projectors should make transparencies from these printouts on a copier or laser printer designed to safely print to acetate.

Note: Please review Module 25: Training of Trainers for more hints on instructional needs and strategies.

Liquefied Petroleum Gas Training Program PAGE 5-1 Liquefied Petroleum MODULE 5: LEGISLATIVE AND REGULATORY POLICIES Gas

POLLUTION LAWS REGARDING ALTE R N A TIVE FUEL VEHICLES Key Points & Notes Air Pollution is a problem that won’t go away. Today, 20 years after Propane: A Global Congress first set standards for air quality, over 100 areas in the Market Place, 10.5 United States have harmful levels of ozone, carbon monoxide, or minutes both. About 133 million people, more than 53 percent of all Americans, are breathing unhealthy air, according to the Environmental Protection Agency (EPA). The worst offender, Los Angeles, is out of compliance over 200 days each year. 5-2 L.A., with all its notoriety as the birthplace of “smog,” isn’t the WELCOME TO only problem area. New York, LOS ANGELES G reater Connecticut, Phila- BIRTHPLACE OF SMOG delphia, Denver, Baltimore , Pop. 3.5 Million Chicago, Milwaukee, Houston, and San Diego all have severely polluted air. Vehicles generate 40 percent of all air pollution nationally. Fleet vehicles such as buses, taxis, police vehicles, and delivery vans operating in urban areas are particularly heavy polluters since they run all day and start, stop, and idle more. In recent years legislation has been passed in an effort to help combat air pollution from transportation. These policies mandate phasing in clean-burning fuel vehicles to reduce toxic and polluting emissions. In many cases, these policies provide incentives and financial support to ease the transition to alternative fuels. The most influential federal policies and programs affecting vehicular transportation fleets are summarized below. With the passage of the 1990 Clean Air Act, fleet vehicles are required to use clean fuels. In the Act, Congress specifically named LP-gas as one of clean fuels that can be part of the solution.

POLICIES IMPLEMENTED THROUGH THE ALTERNATIVE MOTOR FUELS ACT (AMFA). The goal of the Alternative Motor Fuels Act (AMFA) is to encourage the development and use of alternative transportation fuels. The 5-3 act directs the Department of Energy (DOE) to work with other agencies to help encourage and develop the use of LPG, methanol, ethanol, and natural gas as transportation fuels. These agencies are the General Services Administration (GSA), the Department of Transportation (DOT), and the Environmental Protection Agency (EPA), state and local governments, and industry Three programs have been established to fulfill this goal: the Alternative Fuel Light Duty Vehicle Program, the Truck Commercial Application Program, and the Alternative Fuels Bus Te s t i n g Program. The objective of the Alternative Fuel Light Duty Vehicle Program is to ensure that the majority of automobiles and light duty vehicles purchased by the federal government are alternative fuel vehicles. The Truck Commercial Application Program is conducting commercial application projects for alternative fuel vehicles in real- world operating environments. The Alternative Fuels Bus Testing

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Program assists state and local government agencies in testing Key Points & Notes alternative fueled vehicles in urban areas. Another directive implemented by the AMFA is the establishment of the Alternative Fuels Data Center (AFDC). The AFDC (1-800-423- 1DOE) is operated and managed by the National Renewable Energy Laboratory in Golden, Colorado. It gathers and analyzes i n f o rmation on the composition, emissions, operation, and durability of alternative vehicular fuels. FEDERAL ENERGY POLICY ACT (FEPA-92) The Federal Energy Policy Act is designed to initiate the development and implementation of alternative fuel technologies. 5-4 Under the law, $25 million per year will be appropriated for transit and school bus fleets to develop a clean-fuels urban bus program. Another $30 million will be allocated for providing low interest loans. Income tax incentives available through this act include deductions from $2,000 to $50,000 for clean-fuel vehicles and $100,000 for clean-fuel refueling stations. The U.S. Department of Defense and other research and development institutions will receive other financial support. The law req u i r es federal agencies and “fuel providers” (the gas and electric utilities) to convert portions of their fleets as early as 1994. The law also encourages the purchase of more alternative fuel vehicles for federal fleets. Refer to Figure 5-1. Its goal was to purchase 5,000 vehicles during 1993; 7,500 in 1994; and 10,000 in 1995. Federal fleet vehicles that operate on clean fuels should reach 25 percent by 1996, 33 percent by 1997, 50 percent by 1998, and 75 percent by 1999. This increased use of alternative fuels by federal fleets will help accelerate the development of an OEM market. See Table 5-A. NOTE: Executive order No. 12448 (November 1993) has increa s e d by 50 percent the number of alternative fuel vehicles mandated by the 1992 Energy Policy Act for the years 1993 to 1995.

5-5

States with conversion incentives States w/mandated fleet conversions & conversion incentives States with mandated fleet incentives None West Virginia University 5.1 States with mandated fleet conversions and/or conversion incentives.

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SUMMARIZED MANDATES OF THE CLEAN AIR ACT AMENDMENTS Key Points & Notes (CAAA) The Clean Air Act was passed in 1963 and it has been amended several times. The most recent amendments in 1990 initiate 5-6 regulations to begin cleaning the air in cities considered air-quality nonattainment areas. Refer to Figure 5-2 for 1992 data. The CAAA initiates regulations to begin cleaning the air in cities considered air-quality nonattainment areas. Private fleets of 10 or more vehicles in these regions will be required to purchase alternative fuel vehicles beginning in 1998. Fleets operating light- duty vehicles are required to have 30 percent of their new vehicles purchased in 1998 operating on alternative fuels, 50 percent in 1999, and 70 percent thereafter. Fleets operating medium-duty vehicles will have to ensure that 50 percent of their new vehicles operate on alternative fuels. See Table 5-B.

THE CALIFORNIA AIR RESOURCES BOARD (CARB) California is the most proactive state in the U.S. for establishing stringent vehicle emission standards. The air quality in many 5-8 regions in California is so poor the California Air Resources Board decided not to wait until federal mandates take effect. The standards being developed by the CARB are more stringent than those called for by the CAAA. Many states have adopted or are adopting legislation similar to California’s. If standards have not been established by federal agencies pertaining to LPG kits and conversions, the standards adopted by the CARB are recommended. Refer to Figure 5-3 for 1994 progress. Many state and local government agencies have their own policies, incentives, and legislation to implement alternative fuel vehicles. More than 30 states have alternative fuel transportation programs. Many of these states mandate the use of alternative fuels in some

5-7

States containing extreme or severe ozone nonattainment area s States with areas classified marginal, moderate or serious ozone nonattainment None West Virginia University 5.2 Map of National Ozone Nonattainment Areas.

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Key Points & Notes

5-9

States that have adopted or in the process of adopting CA LEV prog r a m States considering adopting the California LEV program None West Virginia University 5.3 Map of California law. applications. Others provide incentive programs such as tax credits, exemptions, rebates, and low-interest loans for owners of alternative fuel vehicles. A complete summary of state-by-state laws and incentive programs can be found by contacting the office of your state Attorney General or your state Department of Transportation.

REGULATIONS ENFORCED BY THE U. S. DEPARTMENT OF TRANSPORTATION (DOT) The Department of Transportation (DOT) is a cabinet level department of the United States government. DOT establishes rules and 5-10 regulations governing interstate transportation of materials. The rules and regulations of the Department of Transportation are covered by Title 49 of the Code of Federal Regulations (CFR), entitled Transportation (Parts 100-199, 301-398).

These specifications and regulations evolved from existing industry Clearing the Air, 17 standards that have been adopted as DOT regulations. minutes

NATIONAL FIRE PROTECTION AGENCY (NFPA-58) RULES AND REGULATIONS The National Fire Protection Association (NFPA) is a nonprofit, voluntary association solely devoted to fire prevention and safety. 5-11 Since 1896, NFPA has published guidelines that are adopted as minimum requirements for fire prevention, fire fighting procedures, and fire protection for many different industries. Motor vehicle fuel storage, dispensing, and engine operation are covered by NFPA pamphlets. The NFPA provides various services to many industries including fire prevention training programs for use in public education programs and technical publications on fire prevention and safety. In addition, one of the most important services provided by NFPA is

Liquefied Petroleum Gas Training Program PAGE 5-5 Liquefied Petroleum MODULE 5: LEGISLATIVE AND REGULATORY POLICIES Gas the coordination of the development of fire safety codes for specific Key Points & Notes industries. The latest edition was published in 1995. There are several fire safety codes used by the LP-gas industry that have been developed in cooperation with or published through the NFPA. For example, the NFPA committee on Liquefied Petroleum Gases worked with many volunteers from the LP-gas industry to develop a standard for the storage and handling of LP-gas. Once developed, it was published by the NFPA and soon became the industry standard for LP-gas storage and handling operations. This standard is Pamphlet #58 in the NFPA pamphlet series of national fire safety codes. It is one of the most important and widely used standards in the industry. For this reason, you should be aware that NFPA Pamphlet #58 includes the following information: 1. General provisions including definitions, scope, etc. 2. LP-gas equipment and appliances including standards for tanks, cylinders, valves, piping and appliances (i.e., vaporizers). 3. Installation of LP-gas Systems including guidelines for installing equipment in bulk plants, cylinder filling stations and industrial and road vehicle information. 4. LP-Gas Transfer – including guidelines for filling tanks and cylinders 5. Truck transportation of LP-Gas including guidelines for transport, bulk truck, and cylinder delivery operations. Your shop safety policy should reflect the appropriate local and state laws that apply. If there is no other standard to follow, refer to National Fire Protection Association No. 58 as a guide. PROPANE RELATED AGENCIES A number of government agencies and private org a n i z a t i o n s Activity 5-1: Internet identify, propose, and influence the laws, codes, and regulations Access pertaining to the LPG vehicle industry. The National Propane Gas Association (NPGA) is researching the marketability of LPG vehicles. The U.S. Department of Transportation (DOT) has developed strict Activity 5-2: Internet standards for the certification, application, and maintenance of LPG Search for Legislative fuel tanks. The National Fire Protection Association (NFPA) has and Regulatory developed strict safety standards applying to all areas of the LPG Policies fuel system. Updated information on these standards and regulations may be obtained by contacting the following: National Propane Gas Association 4301 North Fairfax Drive, Suite 340 Arlington, VA 22203 Department of Transportation 400 7th Street, S.W. Washington, DC 20590 California Air Resources Board 9528 Telstar Avenue El Monte, CA 91731-2900 National Fire Protection Association Batterymarch Park Quincy, MA 02269

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SUMMARY OF PROVISIONS 1992 ENERGY POLICY ACT • The program applies to fleets which contain at least 20 vehicles that are, or capable of, being centrally refueled, and operate in a metro area of 250,000 or more people, and operate at least 50 vehicles in the U.S. • At least 50% of the alternate fuel used by these vehicles must be produced from a domestic source, and the vehicles must operate on the alternate fuel only, unless exempted by applicable authorities. • The vehicle phase-in requirements for this act are as follows: DATE FEDERAL FLEET ALTERNATE FUEL STATE FLEET PRIVATE / PROVIDER MUNICIPAL 1993 5,000 light duty 1994 7,500 light duty 1995 10,000 light duty 1996 25% new purchases 30% new purchases 10% new purchases 1997 33% new purchases 50% new purchases 15% new purchases 1998 50% new purchases 70% new purchases 25% new purchases 1999 75% new purchases 90% new purchases 50% new purchases 20% new purchases 2000 75% new purchases 20% new purchases 2002 30% new purchases 2003 40% new purchases 2004 50% new purchases 2005 60% new purchases 2006 70% new purchases

Table 5-A 1992 Energy Policy Act Summary of Provisions.

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SUMMARY OF PROVISIONS 1990 CLEAN AIR ACT The mobile source provisions of The Clean Air Act Amendments of 1990, Public Law No. 101-549, includes the Amendments below: • A program that requires centrally refueled fleets of 10 or more vehicles to run on clean alternative fuels will be required in 22 urban areas. • Applies to fleets including passenger cars, light duty trucks, medium/heavy duty trucks and up to 26,000 lb. gross vehicle weight. • Covered fleet operators must begin to purchase clean-fueled vehicles in model year 1998 to replace existing vehicles. • Fuel providers must make alternate fuels available where vehicles are currently refueled. • Credits will be awarded, pending an implementation plan, to fleet operators who exceed mandates by purchasing more vehicles than required, purchasing earlier than required, or purchasing vehicles in uncovered categories. • Requires California to implement a pilot program for 150,000 vehicles to be sold each year beginning in 1996, and 300,000 each year beginning in 1999. • Allows for other states with serious, severe or extreme ozone non-attainment areas. They may also adopt the new California emissions standards.

DATE UNDER 6,000 LBS OVER 6,000 LBS OVER 26,000 LBS 1998 30% of all app. fleets 50% of all app. fleets Does not apply 1999 50% of all app. fleets 50% of all app. fleets Does not apply 2000 70% of all app. fleets 50% of all app. fleets Does not apply

Table 5-B 1990 Clean Air Act Summary of Provisions.

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Key Points & Notes

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MODULE REVIEW ITEMS

Note to Technician: Consider all choices carefully and select the best answer to each.

1. The first federal legislation that laid the groundwork for controlling motor vehicle emissions was the _____. A. Clean Air Act of 1963. B. National Ambient Air Quality Standards. C. Alternative Motor Fuels Act of 1988. D. National Emissions Standards Act.

2. The program that requires the government to purchase alternative fuel vehicles and provides incentives for fleets to do the same is known as the _____. A. Alternative Fuel Light-Duty Vehicle Program. B. Clean Fuel Vehicle Program. C. Automobile Commercial Testing Program. D. Truck Commercial Application Program.

3. All of the following are programs that have evolved from the Alternative Motor Fuels Act (AMFA) of 1988 except the _____. A. Alternative Fuel Light Duty Vehicle Program. B. Alternative Fuels Bus Testing Program. C. Truck Commercial Application Program. D. Automobile Commercial Testing Program.

4. Which of the following is responsible for gathering and analyzing information on many facets of alternate fuel vehicles including composition, operation, emissions and durability? A. Department of Energy. B. California Air Resource Board. C. Alternative Fuels Data Center. D. Liquid propane gas Coalition.

5. The main purpose of the Alternative Motor Fuels Act (AMFA) of 1988 is to _____. A. Require all government sectors to use alternative fuel vehicles. B. Encourage the development and use of alternative transportation fuels. C. Discourage the use of gasoline as an efficient transportation fuel. D. Offer consumers incentives to buy LPG vehicles.

6. Strict standards for the certification, application and maintenance of LPG fuel tanks are established by which group? A. National Fire Protection Agency (NFPA). B. Department of Transportation (DOT). C. American Gas Association (AGA). D. Environmental Protection Agency (EPA).

7. Vehicles generate _____ of all air pollution nationally. A. 20%. B. 40%. C. 60%. D. 80%.

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8. The 1992 Energy Policy Act applies to fleets which have the following characteristics? A. Contain at least 20 vehicles. B. Are capable of being centrally refueled. C. Operate in a metro area of 250,000 or more people. D. All of the above.

9. What is the name of any device or modification added onto or designed into a motor vehicle for the purpose of reducing air pollution? A. Evaporative control system. B. Automotive air pollution. C. Emission control.. D. None of the above.

10. Which state has been the most proactive in the U.S. for establishing stringent vehicle emissions standards? A. California. B. Pennsylvania. C. Massachusetts. D. Florida.

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MRI SCORING KEY

1. A 2. D 3. D 4. C 5. C 6. B 7. B 8. D 9. C 10. A

Liquefied Petroleum Gas Training Program

Liquefied Petroleum MODULE 5: LEGISLATIVE AND REGULATORY POLICIES Gas

ACTIVITY 5-1: INTERNET ACCESS

OBJECTIVE

To access and gain exposure to the Internet.

MATERIALS NEEDED “The Fleet Manager’s Primer on Internet Access” Computer access and Internet access Internet access software Computer support personnel available for questions or problems

METHOD This exercise serves as a primer for access to the Internet. Some technicians may have online experience already. Those that have might team up with others that have not to help them with navigation. Practice logging on. Of particular interest are Chapter 4: Browsers and Chapter 5: Search Engines. There are many search engines, and a few of the more popular are: http://www.yahoo.com http://www.lycos.com http://www.hotbot.com Usually more search engines are available by searching for the keywords “Search Engines”. Type in a few keywords of interest and search for “hits”. Access these sites and look around to get the feel of navigation.

QUESTIONS What is the Internet? How can it be of help to you? Open a search engine and enter the keyword “Propane”. What hits did you get? Which hits go to the same site? Which hits contain valuable information? Which hits don’t? Which hits just returned the keyword as part of a text document?

COMMENTS Note that not every organization or piece of information is on the Internet. Also note that not every search engine has every site listed. If you are having difficulty locating a subject, access a couple of search engines or use related keywords. Not mentioned in the Primer was searching a library’s holdings. Most libraries today are online and have their own type of search engine. Access your school or local library (if possible) and perform a search of their holdings. This search is useful to locate materials that are not online but can be checked out or referenced.

Liquefied Petroleum Gas Training Program

Liquefied Petroleum MODULE 5: LEGISLATIVE AND REGULATORY POLICIES Gas

ACTIVITY 5-2: INTERNET SEARCH FOR LEGISLATIVE AND REGULATORY POLICIES

OBJECTIVE

To access Internet sites related to legislative and regulatory policies

MATERIALS NEEDED

“Internet Search for Legislative and Regulatory Policies”

METHOD

This exercise exposes technicians to sites where they can find the latest legislative and regulatory information. Access a computer that is tied into the Internet, log on, open a browser, and open some of the sites of interest listed in the handout. Bookmark those which may be of particular interest. Practice printing out recent incentives and other information. Discuss the information and where you found it with the rest of the class.

QUESTIONS

Are you able to access a site of interest again to check the information or show someone else? Can you find information on the health effects of smog? Can you find the latest information on alternative fuel vehicle policies and regulations? Which site(s) contains this information?

COMMENTS

Sometimes the Internet slows down during hours of heavy use. A program such as WebWhacker can be used to download an entire site to a local hard drive and the browser can access it from there. Ask your computer support personnel for more information.

Liquefied Petroleum Gas Training Program

1 MODULE 5: Legislative and Regulatory Policies 2 POLLUTION LAWS REGARDING ALTERNATIVE FUEL VEHICLES • 100+ US areas have ozone or carbon monoxide problems • Vehicles generate 40% of all air pollution nationally • Regulations, mandates, incentives • The 1990 Clean Air Act specifically names LPG as one of the clean fuels that can be part of the solution 3 POLICIES IMPLEMENTED THROUGH THE ALTERNATIVE MOTOR FUELS ACT (AMFA) • Encourage the development and use of LPG, methanol, ethanol, and natural gas • Programs established: – Alternative Fuel Light Duty Vehicle Program – Truck Commercial Application Program – Alternative Fuels Bus Testing Program • Alternative Fuels Data Center • National Renewable Energy Laboratory 4 FEDERAL ENERGY POLICY ACT (FEPA-92) • Designed to initiate the development of alternative fuels – $25M for clean-fuels programs – $30M for loans – Other incentives • Mandated fleet conversions and conversion incentives • Table 5-A 5 5-1 LEGISLATIVE AND REGULATORY POLICIES 6 SUMMARIZED MANDATES OF THE CLEAN AIR ACT AMENDMENTS (CAAA) • Passed in 1963, amended several times • Regulations to clean the air in cities considered air-quality nonattainment areas • Table 5-B 7 5-2 NATIONAL OZONE NONATTAINMENT AREAS 8 THE CALIFORNIA RESOURCE BOARD (CARB) • California has established most stringent vehicle emission standards • Standards established by CARB are more stringent than those called for by the CAAA 9 5-3 CALIFORNIA LEV LAW 10 REGULATIONS ENFORCED BY THE U.S. DEPARTMENT OF TRANSPORTATION (DOT) • Title 49 of the Code of Federal Regulations • Specifications and regulations evolved from industry standards adopted as DOT regulations 11 NATIONAL FIRE PROTECTION AGENCY (NFPA-58) RULES AND REGULATIONS NFPA-58: – General provisions – LPG equipment and appliances – Installation of LPG systems – LPG transfer – Truck transportation of LPG

MODULE 5: Legislative and Regulatory Policies

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 5-1

POLLUTION LAWS REGARDING ALTERNATIVE FUEL VEHICLES

• 100+ US areas have ozone or carbon monoxide problems • Vehicles generate 40% of all air pollution nationally • Regulations, mandates, incentives • The 1990 Clean Air Act specifically names LPG as one of the clean fuels that can be part of the solution

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 5-2

POLICIES IMPLEMENTED THROUGH THE ALTERNATIVE MOTOR FUELS ACT (AMFA)

• Encourage the development and use of LPG, methanol, ethanol, and natural gas • Programs established: – Alternative Fuel Light Duty Vehicle Program – Truck Commercial Application Program – Alternative Fuels Bus Testing Program • Alternative Fuels Data Center • National Renewable Energy Laboratory

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 5-3

FEDERAL ENERGY POLICY ACT (FEPA-92)

• Designed to initiate the development of alternative fuels – $25M for clean-fuels programs – $30M for loans – Other incentives • Mandated fleet conversions and conversion incentives • Table 5-A

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 5-4

5-1 LEGISLATIVE AND REGULATORY POLICIES

States with conversion incentives States with mandated fleet conversions & conversion incentives

States with mandated fleet incentives None West Virginia University

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 5-5

SUMMARIZED MANDATES OF THE CLEAN AIR ACT AMENDMENTS (CAAA)

• Passed in 1963, amended several times • Regulations to clean the air in cities considered air- quality nonattainment areas • Table 5-B

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 5-6

5-2 NATIONAL OZONE NONATTAINMENT AREAS

States containing extreme or severe ozone nonattainment areas

States with areas classified marginal, moderate, or serious ozone nonattainment

None West Virginia University

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 5-7

THE CALIFORNIA RESOURCE BOARD (CARB)

• California has established most stringent vehicle emission standards • Standards established by CARB are more stringent than those called for by the CAAA

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 5-8

5-3 CALIFORNIA LEV LAW

States that have adopted or are in the process of adopting CA LEV program

States considering adopting the CA LEV program

None West Virginia University

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 5-9

REGULATIONS ENFORCED BY THE U.S. DEPARTMENT OF TRANSPORTATION (DOT)

• Title 49 of the Code of Federal Regulations • Specifications and regulations evolved from industry standards adopted as DOT regulations

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 5-10

NATIONAL FIRE PROTECTION AGENCY (NFPA-58) RULES AND REGULATIONS

NFPA-58: – General provisions – LPG equipment and appliances – Installation of LPG systems – LPG transfer – Truck transportation of LPG

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 5-11

MODULE 6: Basic Combustion Theory

State of Oklahoma College of the Desert West Virginia University

Liquefied Petroleum MODULE 6: BASIC COMBUSTION THEORY Gas

CONTENTS

OBJECTIVES...... i INSTRUCTOR NOTES...... ii THE COMBUSTION PROCESS...... 6-1 ELEMENTS OF GOOD COMBUSTION...... 6-1 COMBUSTION CHAMBER...... 6-5 THE COMBUSTION REACTION...... 6-7 EGR...... 6-8 MODULE REVIEW ITEMS...... 6-11 MRI SCORING KEY...... 6-15 OVERHEAD TRANSPARENCY MASTERS

Liquefied Petroleum Gas Training Program

PAGE 6-i Liquefied Petroleum MODULE 6: BASIC COMBUSTION THEORY Gas

OBJECTIVES

At the completion of this module, the technician will be able to: • Explain the concept of air fuel ratio. • Contrast liquid versus gaseous fuel mixing. • Discuss fuel distribution. • Discuss combustion chamber design. • Discuss ignition quality. • Discuss ignition timing.

Liquefied Petroleum Gas Training Program PAGE 6-ii Liquefied Petroleum MODULE 6: BASIC COMBUSTION THEORY Gas

INSTRUCTOR NOTES

INSTRUCTOR MATERIALS/MEDIA NEEDED Overhead projector or LCD panel/projection equipment Master overhead transparencies or Microsoft PowerPoint 4.0 presentation file Mod6.ppt

Note: Slides correspond to text as indicated by icon

VCR with TV or projection unit

Laboratory Activities: 6-1: Megatech Model Engine

Note: Lab activities correspond to text as indicated by icon

STUDENT MATERIALS/MEDIA NEEDED Module 6: Basic Combustion Theory

OVERHEAD TRANSPARENCY MASTERS The printouts enclosed with this module are taken from the Microsoft PowerPoint 4.0 presentation file Mod6.ppt . Instructors planning to use overhead projectors should make transparencies from these printouts on a copier (or laser printer designed to safely print to acetate.

Note: Please review Module 25: Training of Trainers for more hints on instructional needs and strategies.

Liquefied Petroleum Gas Training Program PAGE 6-1 Liquefied Petroleum MODULE 6: BASIC COMBUSTION THEORY Gas

THE COMBUSTION PROCESS Key Points & Notes The combustion process is very complex and rapid; it changes air and fuel into power and exhaust in milliseconds. Many conditions 6-2 affect combustion quality including: • the ratio of air to fuel; • the temperatures of air and fuel; • load on the engine; • and the type of fuel. These conditions (and more) influence engine performance. Engineers must take into account a wide range of operating conditions designing an engine for best performance and lowest emissions. For an engine to make economical, clean power it must be in good condition and correct adjustment. Understanding the elements of good combustion enables the technician to diagnose problems such as poor performance, high emissions, or both.

ELEMENTS OF GOOD COMBUSTION Three elements are needed to support combustion: air, fuel, and heat. Engine designers are very interested in the diets of their engines; they like to know the temperature of air and composition of fuel that the engine is going to consume. Air temperature, fuel composition, and ignition (heat) are the engine’s food. Air By weight, only 23 percent of the air is oxygen; 76 percent is nitrogen and 1 percent is other gases. The 23 percent oxygen is all 6-3 the engine is interested in; the engine designer wants the temperature of the air to be in a predictable range to make the most of the oxygen to be consumed by the engine. Note: By volume, 21 percent of air is oxygen; 78 percent nitrogen and 1 percent other. Gasoline is harder to vaporize in a cold engine. Warm air helps vaporize the liquid gasoline. Once the engine is warm, colder 6-4 denser air is best because it contains more oxygen so the charge has more energy. 6-5 OXYGEN 23%

NITROGEN 76%

OTHER 1% 6-1 Only 23% of the air is oxygen – by weight.

Liquefied Petroleum Gas Training Program PAGE 6-2 Liquefied Petroleum MODULE 6: BASIC COMBUSTION THEORY Gas

Propane engines always prefer a cool dense charge because propane Key Points & Notes is already a gas. This is why we try to duct cold air into the engine and want the intake manifold to be cool when running on propane. See Module 20 (Air Induction). When fuel and oxygen are mixed in the correct amounts and ignited, they will combust to release energy. Once the fuel is metered in the correct ratio with air and mixed properly with the air, the stage is set for good combustion. Fuel Designers like to know that the composition of the fuel falls in a predictable range of quality. Fuel engineers experiment with blends 6-6 of propane and butane and other gaseous hydrocarbons to get the most stable combustion with cleanest emissions. Ideally, the engineer wants a fuel blend that provides good power, low emissions, and long engine life. The propane sold for cooking may not be the best fuel for a hard working truck engine. Unlike gasoline and diesel, the composition of propane and natural gas is not consistent around the country. This can be a real headache for engine designers trying to get the best performance and emissions and long life from an engine. Ideally, an engine should be built around the fuel that will run it! Most engines are built to run on liquid fuels – gasoline or diesel. Every fuel because of its unique hydrocarbon make-up burns differently. (This book does not go into diesel engines since most engines converted to run on propane are spark ignition not compression ignition/diesel.) Air- Fuel Mixing In carburetted and throttle body fuel injected engines, fuel is introduced above the throttle where the mixing process begins. In 6-7 port fuel injected engines, fuel is introduced close to the intake valve below the throttle. Currently, only one port fuel injection propane system is available on an OEM vehicle in North America. No port fuel injection systems are detailed in this course. Fuel injection systems are being developed for propane engines. Both liquid and vapor propane fuel injection systems are being tried. Liquid is preferred because it is more dense. The fuel is injected close to the intake valve (port injection) like a gasoline fuel- injection engine. Injecting pressurized propane close to the intake valve puts the fuel close the combustion chamber. The intake port and combustion chamber are designed to help mix the charge before ignition for good combustion. Port injection is the most efficient way to insure maximum power and lowest emissions throughout the operating range of the engine. Production propane systems use one of the following air-fuel mixers. • fixed venturi; • air valve; or • central point injection.

Liquefied Petroleum Gas Training Program PAGE 6-3 Liquefied Petroleum MODULE 6: BASIC COMBUSTION THEORY Gas

Unlike liquid gasoline, propane is a gas when it reaches the Key Points & Notes carburetor/fuel injector. The trick is to get the air and the propane to blend. Once mixed, they will stay together. The design and position of the mixing device is critical to ensure good blending of air and fuel. The mixing must be good throughout all engine operating conditions – cold, hot, idle, part and full load. If the engine and related systems are strong and the mixture is right, propane should start the engine easily when cold. A lightly loaded, warm engine will run well on a lean air-fuel mixture with best economy. But most emission-controlled engines should run at stoichiometric or slightly rich to satisfy the catalytic convertor. At full power and heavy load, the mixture should be richest. Gasoline fuel systems, which include the computer controller and other fuel management components, are designed for best power, best economy, and lowest emissions. Propane fuel control systems designed by the OEM car manufacturers are forthcoming.

Fuel Distribution The engine should ideally draw the air-fuel charge into the cylinders in equal amounts. Unfortunately, no engine distributes fuel evenly 6-9 to all cylinders at all load ranges (throttle positions). The length, volume, and shape of the intake manifold and intake ports affect the flow of the air-fuel charge into the combustion chamber. How

1. INTAKE STROKE 2. COMPRESSION 6-8

3. POWER STROKE 4. EXHAUST STROKE

6- 2 In t e r nal combustion proc e s s .

Liquefied Petroleum Gas Training Program PAGE 6-4 Liquefied Petroleum MODULE 6: BASIC COMBUSTION THEORY Gas the engine runs on propane depends a lot on the design of the Key Points & Notes engine as well as the quality of the propane equipment and conversion. Fire – Normal Spark Ignition The spark plug should be positioned in the combustion chamber where ignition will begin and fire will grow to release energy and 6-10 drive the piston down the hole. The plug position should be such that the flame front travels a relatively short distance to complete combustion without autoignition (knock) occurring. Ignition timing is also critical. Propane requires higher ignition voltages than gasoline. Therefore, a top notch ignition system and a turbulent, efficient burning combustion chamber are essential for optimal performance. The design of the combustion chamber and the chamber’s ability to create turbulence as well as spark plug position greatly affect the burn rate and quality of the charge. When gaseous fuels engines are designed to run heavily loaded, lean or both, the position of the spark plug, quality of ignition and ability of the spark plug to ignite the mixture become extremely important. The combustibles must be forced close to the spark plug! N O T E : Most ignition systems are now controlled by the computerized spark timing module. The Powertrain Control Module (PCM) takes inputs from load and combustion sensors to calculate air-fuel ratios and more. Autoignition Also known as detonation and knock, autoignition occurs under loaded engine conditions and is typically caused by the fuel’s 6-11 reaction to cylinder pressure, ignition timing, air temperature and throttle position. Autoignition is not the same as surface ignition; h o w e v e r, autoignition can occur before normal firing of the sparkplugs. Knock occurs after normal spark plug firing. Refer to Figure 6-3.

THE NORMAL FLAME 6-12 FRONT SPREADS (A) AND CYLINDER PRESSURE RISES. UNBURNED END A GASES (B) AUTOIGNITE. A SECOND FLAME FRONT SPREADS. WHEN THE TWO FLAME FRONTS COLLIDE, AN B AUDIBLE VIBRATION IS CR E AT E D . A U T O - I G N I T I O N / K N O C K OCCURS AFTER NORMAL SP ARK IGNITION.

Michele Ortega 6-3 Autoignition (knock/detonation).

Liquefied Petroleum Gas Training Program PAGE 6-5 Liquefied Petroleum MODULE 6: BASIC COMBUSTION THEORY Gas

Surface Ignition Key Points & Notes Surface ignition, also known as pre-ignition, occurs when hot spots in the combustion chamber ignite the air-fuel charge before spark 6-13 ignition. Hot spots are caused by the following: · oil deposits; · sharp, hot metal surfaces; · fuel composition/sensitivity; · wrong spark plug heat range; and · inefficient cooling system.

6-14 THE COMBUSTIBLE AIR/FUEL MIXTURE IS IGNITED BY (A) A GLOWING DEPOSIT; OR (B) A HOT SHARP METAL SURFACE IN THE COMBUSTION C H A M B E R . S U R FACE IGNITION OCCURS BEFORE NORMAL IGNITION. B

Michele Ortega 6-4 Surface ignition (preignition).

COMBUSTION CHAMBER Some of the aspects of engine design that affect combustion quality a re engine displacement, compression ratio, and combustion 6-15 chamber design. These factors are usually out of the control of the technician.

Compression Ratio The compression ratio is the volume of the cylinder at Bottom Dead Center (BDC) compared to Top Dead Center (TDC) of the engine. 6-16 Higher compression engines are more thermally efficient than lower compression. Combustion is enhanced by high compression. The lowest compression ratio used in today’s automotive engines is 8 to 1 (8:1); the highest are 91/2 to 1 (9.5:1). While high compression is more efficient and makes better power and better economy, emissions increase and fuel octane must be higher. Oxides of nitrogen (NOx) emissions increase with compression. Since propane is higher octane than gasoline, it can tolerate a higher compression within limits. However, other factors such as turbulence, altitude,

Liquefied Petroleum Gas Training Program PAGE 6-6 Liquefied Petroleum MODULE 6: BASIC COMBUSTION THEORY Gas

Key Points & Notes

6-17

Michele Ortega 6-5 Compression ratio. load, and rpm contribute to the fuel’s ability to perform properly. Compression should be limited to 9:1 on any hard working engine because most LPG blends misbehave at compressions higher than 9:1 – sea level altitude. Above 12:1 compression ratio little is gained, partially because commercially available fuels don’t act well in such high pressure environments and because mechanical efficiency begins to cancel out gains in thermal efficiency. See Modules 4 and 7. Refer to Figure 6-5.

Turbulence A chamber that creates good turbulence stirs up the air-fuel mixture and makes the flame front burn quickly through the 6-18 combustible charge. This lessens the risk of autoignition (knock).

Squish A chamber that has a good squish deck pushes the combustible charge toward the spark plug and flame front away from the end gas 6-19 region – where unburned gases reside. A chamber with good squish also has good turbulence; a chamber with a small squish deck lowers HC emissions.

Quench This has good and bad qualities. Quench cools the combustible charge and the flame front. If the charge is too cool to support 6-20 combustion, HC emissions will be high. On the other hand, a cool charge will lower the chances for autoignition. NOTE: For low HC emissions, a compact combustion chamber is best with a low surface-to-volume ratio to minimize the effects of quench.

Wedge A wedge shaped combustion chamber has a high surface-to-volume ratio, which increases unburned hydrocarbons but decre a s e s 6-21 tendency to autoignite.

Liquefied Petroleum Gas Training Program PAGE 6-7 Liquefied Petroleum MODULE 6: BASIC COMBUSTION THEORY Gas

Key Points & Notes

6-23

6-6 Hemispherical and wedge combustion chambers. Hemispherical A hemispherical chamber has a low surface-to-volume ratio, which reduces the loss of heat from the chamber and unburn e d 6-22 h y d rocarbons. Hemispherical combustion chambers can be designed to lessen the tendency to autoignite. Summary of Spark Ignition (SI) Spark ignition engines use a high-voltage ignition to provide heat for combustion and they use a throttle to control the weight (density) of the air-fuel entering the engine. At idle, the weight of the air-fuel mixture is less than when the throttle is wide open. An engine is a pump that draws in a fixed volume of air-fuel every stroke; while the volume on any given stroke is the same, the weight will vary with throttle position. THE COMBUSTION REACTION Ideal Combustion If combustion is complete, carbon is oxidized with oxygen. Hydrogen is an element of any hydrocarbon and combines with 6-24 oxygen to produce water (H2O). In ideal combustion, the carbon reacts with oxygen to create carbon dioxide.

C + O2 = CO2; hydrogen reacts with oxygen to create water:

H + H + O = H2O. In reality, combustion is incomplete; exhaust gas contains partially oxidized and unburned gases such as carbon monoxide (CO), u n b u rned hydrocarbons (HC) and oxides of nitrogen (NOx) . Nitrogen enters the combustion reaction as a component of air. Air is 23 percent oxygen, 76 percent nitrogen, and 1 percent inert gases by weight. Nitrogen has no use in the creation of power; it reacts with oxygen to make the exhaust emission NOx. Engine emissions come out looking like this:

N2 + O2 + HC = CO, HC, NOx, CO2, O2 and other stuff.

Liquefied Petroleum Gas Training Program PAGE 6-8 Liquefied Petroleum MODULE 6: BASIC COMBUSTION THEORY Gas

100

0 1.5 1.4 1.3 1.2 1.1 1.0 .9 .8 .7 .6 .5

LEAN A/F RATIOS RICH A/F RATIOS

LAMBDA SCALE Courtesy of Algas Carburetion 6- 7 La m b d a . 6-26 Lambda and Stoichiometry These terms mean the same thing: the ratio of air-to-fuel that produces theoretically ideal combustion. Every fuel has a different 6-25 ideal, chemically-correct air-fuel ratio (lambda l ). The value for ideal combustion of any fuel is l = 1.0. A rich mixture is less than l < 1.0; a lean mixture is greater than l > 1.0.

EGR Exhaust gas recirculation (EGR) is used to lower peak combustion temperatures by displacing the combustible air-fuel charge with 6-27, 6-28 exhaust gas. EGR dilution lowers oxides of nitrogen emissions and slows combustion. EXHAUST RADIATION – 20–40 % Heat Loss No RA D I A TION – 1–5% engine is 100 perce n t IN C O M P L E T E ef ficient. In fact an engine CO M B U S T I O N – 2 – 5 % looses far more energy than it converts to work. For COOLANT – 15–30% ex a m p l e . . . TRANSMISSION – 1–5% FRICTION – 7–38% AVAILABLE POWER TO THE WHEELS – 0–15% Professor Fox explains...

Liquefied Petroleum Gas Training Program PAGE 6-9 Liquefied Petroleum MODULE 6: BASIC COMBUSTION THEORY Gas

Volumetric Efficiency Key Points & Notes The calculation or measure of an engine’s ability to breathe. Volumetric efficiency (VE) is the ratio of pressure inside the cylinder 6-29 at BDC compared to atmospheric pressure. VE is the ratio of actual cylinder capacity to the amount of air the engine actually takes in; it varies with compression ratio. Although the term is volumetric efficiency, it is really a ratio of masses, not volumes. A throttled, spark ignited engine has highest volumetric efficiency at wide open throttle (WOT) at whatever RPM the engine best operates, which is determined by many design features. A fuel injected engine is more 6-1: Megatech Model volumetrically efficient than a carburetted engine because it has no Engine venturi restriction.

Liquefied Petroleum Gas Training Program PAGE 6-10 Liquefied Petroleum MODULE 6: BASIC COMBUSTION THEORY Gas

Key Points & Notes

Liquefied Petroleum Gas Training Program PAGE 6-11 Liquefied Petroleum MODULE 6: BASIC COMBUSTION THEORY Gas

MODULE REVIEW ITEMS

Note to Technician: Consider all choices carefully and select the best answer to each. 1. Which conditions affect the quality of combustion? A. The load on the engine. B. The fuel type. C. The ratio of and temperatures of air and fuel. D. All of the above.

2. A number of elements are needed to support good combuston. They are: A. Fuel, heat, and water. B. Fuel, heat, and air. C. Air temperature, fuel, and heat. D. Air and fuel.

3. The correct percentage composition of air by weight is: A. Nitrogen 76%, Oxygen 23%, Etc. 1%. B. Etc. 5%, Nitrogen 70%, Oxygen 25%. C. Oxygen 21%, Nitrogen 78%, Etc. 1%. D. Oxygen 15.5%, Nitrogen 72.2%, Etc. 4.7%.

4. Which ofthe following statements is true? A. Propane engines prefer a warm dense charge. B. Gasoline is easier to vaporize in a cold engine. C. Liquid gasoline is vaporized easier by warm air. D. Warmer denser air is preferred in warmer engines.

5. The composition of propane (but not natural gas) is consistent throughout the country. A. True. B. False.

6. Most engines are built to run on _____ fuels. A. Solids. B. Liquids. C. Gases. D. B and C.

7. _____ is the most efficient way to get maximum power and low emissions thoughout the engine operating ranges. A. Carburetion. B. Port injection. C. Fuel injection. D. All of the above.

8. Once mixed, LPG and air will stay together. A. True. B. False.

Liquefied Petroleum Gas Training Program PAGE 6-12 Liquefied Petroleum MODULE 6: BASIC COMBUSTION THEORY Gas

9. If the mixture is _____, propane should start the engine easily when _____. A. Correct; warm. B. Correct; cold. C. Neither A or B. D. Both A and B.

10. Mixing must be good throughout which engine operating condition(s)? A. Cold and hot. B. Idle. C. Full and part load. D. All of the above.

11. Which sequence describes the internal combustion process? A. Power, exhaust, compression, intake. B. Compression, intake, exhaust, power. C. Intake, compression, power, exhaust. D. Intake, power, compression, exhaust.

12. Under loaded engine conditions, _____ is caused by the fuel's reaction to cylinder pressure, ignition timing, air temperature, and throttle position. A. Knock. B. Detonation. C. Autoignition. D. Any one of the above.

13. Surface ignition is caused by _____. A. Fuel composition/sensitivity. B. Round, cold metal surfaces. C. Correct spark plug heat range. D. Efficient cooling system.

14. The lowest compression ratio used in today's automotive engines is _____; the highest is _____. A. 8:1; 10:1. B. 8.5:1; 9.5:1. C. 8.0:1; 9.5:1. D. 8:1; 9:1.

15. Good _____ lessens knock, small _____ lowers HC emissions. A. Quench; squish. B. Quench; turbulence. C. Quench; quench. D. Turbulence; squish.

16. Ideal combustion is: A. C + O2 = COO; H + H + O =HHO. B. C + O = CO; H + H + O = HHO. C. C + H4 = CH4; H2 + 0 = H 2O. D. N 2 + CO2 = NCO + O2.

Liquefied Petroleum Gas Training Program PAGE 6-13 Liquefied Petroleum MODULE 6: BASIC COMBUSTION THEORY Gas

17. Real combustion is: A. E = M(C2). 2 2 2 2 B. N + O + HC = CO, HC, NOX, CO , O , etc. C. C + O2 = COO; H + H + O =HHO. D. N2 + O2 + HC + CO2 = CO + HC.

18. A rich mixture is less than lambda < 1.0. A. True. B. False.

19. Exhaust radiation constitutes what percent of engine loss? A. 1-5%. B. 7-38%. C. 2-5%. D. 20-40%.

20. A carburetted engine is more volumetrically efficient than a fuel injected engine. A. True. B. False.

Liquefied Petroleum Gas Training Program

PAGE 6-15 Liquefied Petroleum MODULE 6: BASIC COMBUSTION THEORY Gas

MRI SCORING KEY

1. D 2. B 3. A 4. C 5. B 6. B 7. B 8. A 9. D 10. D 11. C 12. D 13. A 14. C 15. D 16. A 17. B 18. A 19. D 20. B

Liquefied Petroleum Gas Training Program

Liquefied Petroleum MODULE 6: BASIC COMBUSTION THEORY Gas

ACTIVITY 6-1: MEGATECH MODEL ENGINE

OBJECTIVE To operate a one cylinder model of an internal combustion engine. To operate the engine on various fuels. To create lean and rich fuel mix ratios and observe their effects. To adjust engine timing and observe its effects. To observe emissions as related to fuel type, fuel mix, and timing.

MATERIALS NEEDED MEGATECH Model Engine and its instructions. Fuels- gasoline, propane torch canister, acetone (or finger nail polish remover), etc. Exhaust gas analyzer. Shop air and combination air regulator and filter. Basic hand tools.

METHOD

SAFETY NOTE- THE OPERATION OF THE MODEL ENGINE INVOLVES THE SAME CONSIDERATIONS AND PRECAUTIONS AS THAT OF ANY INTERNAL COMBUSTION ENGINE. MAKE SURE ADEQUATE VENTILATION IS PROVIDED. SEE ENGINE INSTRUCTIONS FOR OTHER SAFETY SPECIFICS. HAVE A FIRE EXTINGUISHER AND FIRST AID KIT IN THE IMMEDIATE AREA. Be familiar with the construction and operation of the MEGATECH model engine. Have its instructions on hand. Turn on the gas analyzer and let it warm up. Load the fuel containers with the desired liquid fuel or attach the gaseous fuel lines to the intake and adjust their flow properly. Attach the shop air to the air regulator, lower the output PSI to its proper adjustment, and run the line to the air intake port on the engine. Start the engine on the liquid fuel. If started manually, make sure the engine is anchored well. One person might pull the cord while another adjusts the bleeder valves and throttle. Adjust the bleeder valves and throttle to increase and maintain idle. It may take a few cranks to start the engine. Hook up the gas analyzer probe to the exhaust and enter the real time emissions mode. Determine which fuel(s), RPM settings, and timing will be used, adjust the engine settings as necessary, and fill out the report. When completed, stop the engine, and disassemble the components according to your instructor.

Liquefied Petroleum Gas Training Program

Liquefied Petroleum MODULE 6: BASIC COMBUSTION THEORY Gas

Fuel Type: ______

RPM Setting Timing HC CO CO2 O2

2500 RPM Advance ______

2500 RPM Retard ______

1000 RPM Advance ______

1000 RPM Retard ______

RPM ______Advance ______

RPM ______Retard ______

Fuel Type: ______

RPM Setting Timing HC CO CO2 O2

2500 RPM Advance ______

2500 RPM Retard ______

1000 RPM Advance ______

1000 RPM Retard ______

RPM ______Advance ______

RPM ______Retard ______

Liquefied Petroleum Gas Training Program Liquefied Petroleum MODULE 6: BASIC COMBUSTION THEORY Gas

Fuel Type: ______

RPM Setting Timing HC CO CO2 O2

2500 RPM Advance ______

2500 RPM Retard ______

1000 RPM Advance ______

1000 RPM Retard ______

RPM ______Advance ______

RPM ______Retard ______

QUESTIONS

What effect did timing changes have on emissions? What effect did rich and lean fuel changes have on emissions? What differences were observed between fuels?

COMMENTS

The engine will be loud, so most instruction should be provided prior to the activity. Set up the experiment noting which portions of the report should be filled out.

Liquefied Petroleum Gas Training Program 1 MODULE 6: Basic Combustion Theory 2 THE COMBUSTION PROCESS • Combustion quality influences: • Air to fuel ratio • Air and fuel temperature • Engine load • Fuel type 3 AIR • Composition: • Oxygen- 23% • Nitrogen- 76% • Carbon Dioxide and Others- 1% 4 AIR • Gasoline harder to vaporize in a cold engine • Colder denser air better in a warm engine • LPG prefers cool dense charge 5 6-1 AIR BY WEIGHT 6 FUEL • Blends should provide: – Good power – Low emissions – Long engine life • Blend consistency • Most engines built to run on liquid fuels 7 AIR-FUEL MIXING • Carburetted and TBFI engines • Port injection • LPG air fuel mixers: – Fixed venturi – Air valve – Central point injection • Blending considerations • Mixing throughout engine operation conditions: – Cold, hot, idle, part-, and full-load 8 6-2 INTERNAL COMBUSTION 9 FUEL DISTRIBUTION • Intake manifold and ports vs. air-fuel charge into combustion chamber: – Length – Volume – Shape 10 FIRE - NORMAL SPARK IGNITION • LPG needs higher ignition voltages • Optimal performance considerations: – Spark plug position – Ignition quality – Plug able to ignite mixture 11 AUTOIGNITION • Detonation, knock • VS. Surface ignition 12 6-3 AUTOIGNITION 13 SURFACE IGNITION • Pre-ignition • Hot spots caused by: – Oil deposits – Sharp, hot metal surfaces – Fuel composition/sensitivity – Wrong spark plug heat range – Inefficient cooling system 14 6-4 SURFACE IGNITION 15 COMBUSTION CHAMBER • Quality combuston affected by: – Engine displacement – Compression ratio – Combustion chamber design 16 COMPRESSION RATIO • Volume at DBC - TDC • Combustion enhanced by higher compression • Range from 8:1 to 9.5:1 • Effects • Limits 17 6-5 COMPRESSION RATIO 18 TURBULENCE • Stirs up mixture • Effects 19 SQUISH • Pushes charge toward plug • Effects 20 QUENCH • Cools charge and flame front • Effects 21 WEDGE • Shape type of combustion chamber • High surface-to-volume ratio • Effects 22 HEMISPERICAL • Shape type of combustion chamber • Low surface-to-volume ratio • Effects 23 6-6 HEMISPERICAL AND WEDGE COMBUSTION CHAMBERS 24 IDEAL COMBUSTION • Ideal:

– C + O2 = CO2

– H2 + O = H2O • Real:

– N2 + O2 + HC =

– CO, HC, NO X, CO2, O2, etc. 25 LAMBDA AND STOICHIOMETRY • Ratio of air:fuel that produces theoretically ideal combustion • Characteristic of each fuel • Ideal: Lambda = 1.0 • Rich: Lambda < 1.0 • Lean: Lambda > 1.0 26 6-7 LAMBDA & STOICHIOMETRY 27 EGR • Exhaust gas recirculation • Effects 28 HEAT LOSS • Exhaust radiation- 20-40% • Radiation- 1-5% • Incomplete combustion- 2-5% • Coolant- 15-30% • Transmission- 1-5% • Friction- 7-38% • Available power to wheels- 0-15% 29 VOLUMETRIC EFFICIENCY • Measure of engine's ability to breathe • Cylinder pressure at BDC:atmospheric pressure • Ratio of masses, not volumes • Effects

MODULE 6: Basic Combustion Theory

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 6-1

THE COMBUSTION PROCESS

• Combustion quality influences: • Air to fuel ratio • Air and fuel temperature • Engine load • Fuel type

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 6-2

AIR

• Composition: • Oxygen- 23% • Nitrogen- 76% • Carbon Dioxide and Others- 1%

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 6-3

AIR

• Gasoline harder to vaporize in a cold engine • Colder denser air better in a warm engine • LPG prefers cool dense charge

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 6-4

6-1 AIR BY WEIGHT

OXYGEN 23%

NITROGEN 76%

OTHER 1%

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 6-5

FUEL

• Blends should provide: – Good power – Low emissions – Long engine life • Blend consistency • Most engines built to run on liquid fuels

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 6-6

AIR-FUEL MIXING

• Carburetted and TBFI engines • Port injection • LPG air fuel mixers: – Fixed venturi – Air valve – Central point injection • Blending considerations • Mixing throughout engine operation conditions: – Cold, hot, idle, part-, and full-load

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 6-7

6-2 INTERNAL COMBUSTION

1. INTAKE STROKE 2. COMPRESSION

3. POWER STROKE 4. EXHAUST STROKE Peter Aschwanden College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 6-8

FUEL DISTRIBUTION

• Intake manifold and ports vs. air-fuel charge into combustion chamber: – Length – Volume – Shape

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 6-9

FIRE - NORMAL SPARK IGNITION

• LPG needs higher ignition voltages • Optimal performance considerations: – Spark plug position – Ignition quality – Plug able to ignite mixture

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 6-10

AUTOIGNITION

• Detonation, knock • VS. Surface ignition

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 6-11

6-3 AUTOIGNITION

The combustible air/fuel mixture is ignited by (A) a glowing deposit; or (B) a hot sharp metal surface in the combustion chamber. Surface ignition occurs before normal ignition. A

Michele Ortega

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 6-12

SURFACE IGNITION

• Pre-ignition • Hot spots caused by: – Oil deposits – Sharp, hot metal surfaces – Fuel composition/sensitivity – Wrong spark plug heat range – Inefficient cooling system

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 6-13

6-4 SURFACE IGNITION

The combustible air/fuel mixture is ignited by (A) a glowing deposit; or (B) a hot sharp metal surface in the combustion chamber. Surface ignition occurs before normal ignition. B

Michele Ortega

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 6-14

COMBUSTION CHAMBER

• Quality combuston affected by: – Engine displacement – Compression ratio – Combustion chamber design

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 6-15

COMPRESSION RATIO

• Volume at DBC - TDC • Combustion enhanced by higher compression • Range from 8:1 to 9.5:1 • Effects • Limits

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 6-16

6-5 COMPRESSION RATIO

Michele Ortega

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 6-17

TURBULENCE

• Stirs up mixture • Effects

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 6-18

SQUISH

• Pushes charge toward plug • Effects

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 6-19

QUENCH

• Cools charge and flame front • Effects

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 6-20

WEDGE

• Shape type of combustion chamber • High surface-to-volume ratio • Effects

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 6-21

HEMISPERICAL

• Shape type of combustion chamber • Low surface-to-volume ratio • Effects

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 6-22

6-6 HEMISPERICAL AND WEDGE COMBUSTION CHAMBERS

Michele Ortega

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 6-23

IDEAL COMBUSTION

• Ideal:

– C + O2 = CO2

– H2 + O = H2O • Real:

– N2 + O2 + HC =

– CO, HC, NOX, CO2, O2, etc.

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 6-24

LAMBDA AND STOICHIOMETRY

• Ratio of air:fuel that produces theoretically ideal combustion • Characteristic of each fuel • Ideal: Lambda = 1.0 • Rich: Lambda < 1.0 • Lean: Lambda > 1.0

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 6-25

6-7 LAMBDA & STOICHIOMETRY

1.5 1.4 1.3 1.2 1.1 1.0 .9 .8 .7 .6 .5

LAMBDA SCALE Courtesy of Algas Carburetion

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 6-26

EGR

• Exhaust gas recirculation • Effects

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 6-27

HEAT LOSS

• Exhaust radiation- 20-40% • Radiation- 1-5% • Incomplete combustion- 2-5% • Coolant- 15-30% • Transmission- 1-5% • Friction- 7-38% • Available power to wheels- 0-15%

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 6-28

VOLUMETRIC EFFICIENCY

• Measure of engine's ability to breathe • Cylinder pressure at BDC:atmospheric pressure • Ratio of masses, not volumes • Effects

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 6-29

MODULE 7: Basic Emissions and Controls

State of Oklahoma College of the Desert West Virginia University

Liquefied Petroleum MODULE 7: BASIC EMISSIONS AND CONTROLS Gas

CONTENTS

OB J E C T I V E S ...... 7 - i INSTRUCTOR NOTES...... 7 - i i HI S T O R Y & ORIGINATION OF VEHICLE EMISSION STAN D A R D S ...... 7 - 1 EMISSIONS OF CONCERN ...... 7 - 2 N O M E N C L ATURE AND ACRONYMS...... 7 - 2 UNBURNED HYDROCARBONS (HC)...... 7-2 CARBON MONOXIDE (CO)...... 7-3

OXIDES OF NITROGEN (NOX)...... 7-4

CARBON DIOXIDE (CO2)...... 7-5

OXYGEN (O2) ...... 7-5 EVAPORATIVE EMISSIONS...... 7-6 AIR-FUEL RATIOS AND EXHAUST GASES ...... 7-6 CATALYTIC CONVERTER REACTIONS...... 7-7 EFFECTS OF VARIOUS FUELS AND EXHAUST GASES ...... 7-9 HISTORY OF CALIFORNIA EMISSIONS STANDARDS AND THE LEV EMISSION STANDARDS ...... 7-9 WHERE TO FIND EMISSION STANDARDS FOR YOUR LOCALITY...... 7-10 DEVELOPMENT OF EMISSION CONTROL SYSTEMS...... 7-10 UNDERSTANDING FEEDBACK SYSTEMS...... 7-13 INPUT SENSORS...... 7-13 OUTPUT ACTUATORS...... 7-16 MODULE REVIEW ITEMS...... 7-19 MRI SCORING KEY...... 7-23 OVERHEAD TRANSPARENCY MASTERS

Liquefied Petroleum Gas Training Program

PAGE 7-i Liquefied Petroleum MODULE 7: BASIC EMISSIONS AND CONTROLS Gas

OBJECTIVES

At the completion of this module, the technician will be able to: • Discuss the history and origination of vehicle emission standards. • Discuss emissions of concern & nomenclature and acronyms of emissions. • Discuss the impacts of each emission on health and the environment. • Identify the origin of each emission. • Discuss exhaust gases in the exhaust stream. • Discuss the history of California emissions standards and the LEV emission standards. • Identify sources for emission standards and regulations. • Discuss the development of emission control systems and components. • Discuss closed loop theory. • Identify and characterize input sensors and output actators.

Liquefied Petroleum Gas Training Program PAGE 7-ii Liquefied Petroleum MODULE 7: BASIC EMISSIONS AND CONTROLS Gas

INSTRUCTOR NOTES

INSTRUCTOR MATERIALS/MEDIA NEEDED Overhead projector or LCD panel/projection equipment Master overhead transparencies or Microsoft PowerPoint 4.0 presentation file Mod7.ppt

Note: Slides correspond to text as indicated by icon

VCR with TV or projection unit

STUDENT MATERIALS/MEDIA NEEDED Module 7: Basic Emissions and Controls

OVERHEAD TRANSPARENCY MASTERS The printouts enclosed with this module are taken from the Microsoft PowerPoint 4.0 presentation file Mod7.ppt . Instructors planning to use overhead projectors should make transparencies from these printouts on a copier (or laser printer designed to safely print to acetate.

Note: Please review Module 25: Training of Trainers for more hints on instructional needs and strategies.

Liquefied Petroleum Gas Training Program PAGE 7-1 Liquefied Petroleum MODULE 7: BASIC EMISSIONS AND CONTROLS Gas

HI S T O R Y & ORIGINATION OF VEHICLE EMISSION STAN D A R D S Key Points & Notes The history of motor vehicle emissions controls dates back to the 1940s in Los Angeles when the first studies were done to determine 7-2 the damage that air pollution caused to health and property. Industrial dust (particulated) emissions were regulated first in California in 1948. Later studies showed that motor vehicles were a major contributor to urban air pollution and that strategies were needed to curb their contribution. Federal legislation addressing emissions from motor vehicles first appeared in 1955. Since that time, it has been a continuous process of revising, updating, and adding to that original legislation. The first significant piece of federal legislation that laid the groundwork for controlling motor vehicle emissions was the Clean 7-3 Air Act of 1963. While it was very general in nature, it initiated a complex process designed to reduce air pollution.

7-4

1936 1966 1996 Peter Aschwanden 7-1 Sixty years of LA smog.

The Clean Air Act Amendments of 1968 established the first emissions standards that auto manufacturers had to meet in order to sell vehicles to the U.S. public. These standards, 1.5 percent CO and 275 ppm HC as measured at idle by a 2-gas infrared analyzer,

Liquefied Petroleum Gas Training Program PAGE 7-2 Liquefied Petroleum MODULE 7: BASIC EMISSIONS AND CONTROLS Gas forced automotive technology in the direction of building cleaner Key Points & Notes burning cars. These standards remained in effect for 2 years: 1968 and 1969. EMISSIONS OF CONCERN NO M E N C L A TURE AND ACRONYMS It is important that LPG technicians understand emissions created in the exhaust stream and their effect on vehicle performance and 7-5 the environment. These emissions must be dealt with in a manner such that the lowest levels of emissions are achieved while maintaining acceptable vehicle driveability and operating performance. The Environmental Protection Agency (EPA) has identified three pollutants emitted in the exhaust stream of motor vehicles deemed hazardous to human health and the environment. These pollutants together are commonly referred to as total hydrocarbons (THC), carbon monoxide (CO), and nitrogen oxides (NOx). The amounts of these pollutants, measured in grams/mile (gpm), that vehicles can produce have been tested and certified since 1968 and have been reduced significantly. In the last 25 years emissions from light-duty vehicle tailpipes have been reduced by over 90 percent, as noted in the Motor Vehicle Manufacturers Association 1992 Annual Facts and Figures Report.

UNBURNED HYDROCARBONS (HC) Unburned hydrocarbons (HC) are hydrogen- and carbon-containing compounds that are the principal components of today’s motor 7-6 vehicle fuels. Fuels used in most vehicular engines are hydrocarbon compounds. Unburned hydrocarbons are not oxidized in the combustion process; they are usually the result of engine misfiring, or poor air-fuel mixing/distribution or both. Incomplete combustion results in raw fuel being mixed with the exhaust gases. They also result from the quenching effects, when the burning flame front of combustion is extinguished by the relatively cool surfaces of the combustion chamber. An excessively rich air-fuel mixture can also contribute to unburned hydrocarbons because there is too little oxygen to support good combustion. Because of the many types of HC combinations possible, the measurement of HC for emissions regulation purposes is stated in “total mass” rather than measuring each individual compound. This mass measurement is usually re f e r red to as total hydrocarbons or THC reading. Unburned hydrocarbons are regulated for two primary reasons. One is that some hydrocarbons are considered carcinogenic and, therefore, a health hazard. The gases can be inhaled or absorbed into a person’s body and reside there long enough to affect health. The second reason is that many are photochemically reactive in the a t m o s p h e re. These reactive hydrocarbons contribute to the formation of ozone and atmospheric smog, both of which are very damaging to the environment and human health.

Liquefied Petroleum Gas Training Program PAGE 7-3 Liquefied Petroleum MODULE 7: BASIC EMISSIONS AND CONTROLS Gas

Key Points & Notes GASOLINE LPG TOTAL HC TOTAL HC 7-8 100%REACTIVE 60%REACTIVE

Peter Aschwanden 7-2 Unburned hydrocarbons/THC and others.

Finally it should be pointed out that, when interpreting tail pipe test results of LPG vehicles, the hydrocarbon number (ppm) must be 7-7 separated into three categories: 1) total hydrocarbons (THC), which may be the same or higher than the THC of a similar gasoline vehicle; 2) reactive hydrocarbons; 3) non-reactive hydrocarbons. Note: THC is the number in parts per million (ppm) displayed on automotive shop exhaust analyzers. Reactive hydrocarbons, which make up the greatest mass of HC emissions, react with sunlight, heat, moisture, and other compounds in the atmosphere to create pollution. Non-reactive hydrocarbons do not create smog. Gasoline THC emissions are 100 percent reactive; only 60 percent of the propane THC emissions are reactive. The re a c t i v e hydrocarbon number will usually be cited in reference to the reduced emissions of LPG and natural gas. The EPA has required that LPG vehicles meet the same THC requirements as similar gasoline vehicles.

CARBON MONOXIDE (CO) Carbon monoxide (CO) emissions are the result of incomplete combustion of the air-fuel mixture or a rich mixture in one or more 7-9 cylinders. If there isn’t enough oxygen to support combustion, CO goes up and carbon dioxide (CO2) goes down. Quite simply, if the chemical reaction started by the ignition of the air-fuel mixture is totally completed, then the only carbon/oxygen compound that is

A 4 gas analyzer reads percentage of total CO emissions by volume (concentration). An emissions test laboratory measures parts per million then calculates mass (weight) of CO in grams per mile. Ambient CO is taken into consideration. A four cylinder (175 CID) engine pumps half that of an 8 cylinder (350 CID) engine, at the same RPM. While the percent of CO might be the same for both engines, the mass for the 350 CID will be greater than for the 175 CID.

Liquefied Petroleum Gas Training Program PAGE 7-4 Liquefied Petroleum MODULE 7: BASIC EMISSIONS AND CONTROLS Gas

emitted out the tailpipe should be carbon dioxide (CO2). However, Key Points & Notes real situations involve an incomplete oxidizing process of the air- fuel mixture, and the result is the formation of carbon monoxide (CO). Incomplete combustion is caused by the poor mixing of the air and fuel in the combustion chamber or the lack of air, particularly oxygen (O2), in the air-fuel mixture. This can be attributed to a rich air-fuel mixture caused by problems such as a restricted air induction system, high altitude operation, m a l a d j u s t m e n t / f a i l u re of the fuel metering circuitry, or poor (uneven) mixture distribution to the engine cylinders. Carbon monoxide is a colorless, odorless gas that can be deadly to humans and animals if inhaled in sufficient quantities. Carbon monoxide is readily absorbed into the bloodstream, displacing oxygen and can lead to asphyxiation. LPG has the potential for lowered carbon monoxide emissions if the conversion system is properly designed, correctly installed, and adjusted. This is because oxygen and propane are gases and can be mixed well. Gasoline, a liquid, is more difficult to vaporize and mix. Typical test results of vehicles that have been properly converted and adjusted have shown significant reductions in CO over gasoline fueled vehicles and have a positive influence on air quality. HOWEVER, if installed poorly and adjusted improperly, CO emissions from a propane engine can easily exceed gasoline.

OXIDES OF NITROGEN (NOX)

Nitrogen oxides (NOX) are another type of pollutant that is grouped together as one for measuring purposes. They include: 7-10 • NO – Nitric Oxide,

• NO2 – Nitrogen Dioxide,

• NO3 – Nitrous Oxide, • And others. Air is made up of 76 percent nitrogen, which explains its presence in exhaust. However, nitrogen provides no benefit to combustion.

Some NOx compounds act as irritants that affect the eyes and respiratory system of humans making it hard to see and brea t h e . These NOx compounds can also cause plant and property damage and react in the atmosphere to form photochemical smog and acid rain. Ni t r ogen oxides are created in a very complex set of chemical reactions that are primarily formed in the combustion process when 7-11 combustion temperature is high. NOx pr oduction is somewhat sensitive to air-fuel ratio. NOx is even more affected by excessive timing advance. When the air-fuel mixture is lean of stoichmetric, NO X fo r mation increases until the air-fuel mixture reaches about 16:1 when NOX starts dropping. Unfortunately, peak NOx pro d u c t i o n occurs when HC and CO production are low and combustion is good. But running lean has other problems; theref o r e, a compromise in the ai r -fuel ratio must be achieved in order to reduce all pollutants. Refer Figure 7-3. The LPG technician must make every effo r t possible to achieve a stoichiometric air-fuel ratio to keep pollutant emissions do w n .

Liquefied Petroleum Gas Training Program PAGE 7-5 Liquefied Petroleum MODULE 7: BASIC EMISSIONS AND CONTROLS Gas

Key Points & Notes Stoichiometric range of the catalyst (window) – also known as Lambda l 7-12 NOx

HC CO

UPSTREAM OF 3-WAY CAT

NOx HC

John Hilgerdt

DOWNSTREAM OF 3-WAY CAT 7-3 Exhaust gas emission control, pre- and post-3-way catalyst.

NO T E : Gaseous fuels engines are designed to run on extrem e l y lean mixtures – called lean-burn engines. This is done along with high compression and super (turbo) charging to get good ef ficiency and economy. This strategy can lower NOx dr a m a t i c a l l y . The mixture is so lean that NOx starts dropping. Lean burn engines are available in natural gas heavy duty engines. Prop a n e models are in the works. Most light duty automotive engines are designed to operate with a reactive (NOx) type catalytic converter; they must burn very close to stoichiometric – not too lean, yet rich enough to keep the catalyst active and at peak efficiency.

CARBON DIOXIDE (CO2)

CO2 is a natural byproduct of consuming carbon and oxygen. In fact, our bodies produce CO2 in digestion and breathing. This is normal and relatively safe. However, it is considered a greenhouse gas and contributor to global warming. LPG and natural gas will produce less carbon dioxide than gasoline.

OXYGEN (O2) Air contains 23 percent oxygen by weight and is necessary for combustion. The amount of oxygen in the exhaust gas indicates the quality of combustion. A high oxygen percentage on a 4- or 5-gas analyzer means the air-fuel ratio is lean; a low reading indicates a rich air-fuel ratio.

Liquefied Petroleum Gas Training Program PAGE 7-6 Liquefied Petroleum MODULE 7: BASIC EMISSIONS AND CONTROLS Gas

Key Points & Notes

7-14

Photo © Harris Fogel 7-4 Example of refueling emissions (older LPG fill shown).

EVAPORATIVE EMISSIONS Evaporative emissions of unburned hydrocarbons occur in gasoline fueled vehicles when the liquid fuel evaporates and escapes into the 7-13 atmosphere. They can also be emitted in the propane fueling process. Evaporative emissions are regulated because some are c a rcinogenic and photochemically reactive. One example of evaporative emission loss is in refueling of gasoline fueled vehicles. The filler cap is removed and the vapors escape from the tank. Also, a bad seal on the filler cap could result in a prolonged evaporative leak. The LPG fuel system must also be totally sealed so that no LPG leaks out of the system under normal operating circumstances. It is very important that the complete fuel system of every converted vehicle be pressure tested for system integrity. Leak detection and repair of the system is recommended once every 12 months after the vehicle has gone into service. Few leaks ever develop during normal vehicle service if the conversion has been done properly by qualified technicians. Older LPG conversions used a tank that did not include a fixed liquid level gauge; instead they relied on a 80 percent fill level escape valve. The filling of the vehicle was complete when LPG came out of the valve and only then the filling process was stopped and the valve closed. This caused concern with the EPA and this escaped gas during filling must be taken into account when measuring THC’s. With the advent of the new tanks, which close off the LPG filling process automatically, evaporative emissions are reduced significantly. AIR-FUEL RATIOS AND EXHAUST GASES For hydrocarbon fuels such as propane, methane and gasoline, the major hydrocarbon in each can be expressed as follows: 7-15

• for LPG the major HC is C3H8 (propane);

Liquefied Petroleum Gas Training Program PAGE 7-7 Liquefied Petroleum MODULE 7: BASIC EMISSIONS AND CONTROLS Gas

• for natural gas the major HC is CH4 (methane); Key Points & Notes

• for gasoline one major HC is C 8H18 (octane). In general, the following combustion reaction takes place inside the combustion chamber: FUEL + OXIDIZER = COMBUSTION PRODUCTS

(For complete oxidation of propane, 5 molecules of O2 are needed) The equation for propane can be written ideally as:

Air = (O2 + 3.76 N2) per molecule of O2.

With Pure O2:

C3H8 + 5O2 ® 3CO2 + 4H2O But the reality of propane combustion is: With Air:

C3H8 + 5 (O2 + 3.76 N2) ® 3CO2 + 4H2O + 18.80 N2 + minor amounts of CO and partially oxidized HC + NO + NO2 Common gasoline fuel mixtures contain over one hundre d hydrocarbons; therefore, the chemistry involved in the combustion process becomes more complicated.

Partially oxidized HC + NO + NO2 + sunlight => Photochemical SMOG

Peter Aschwanden

CATALYTIC CONVERTER REACTIONS A catalyst is a substance used to create and speed up a chemical reaction or chemical change. The catalytic converter, therefore, provides an additional area to oxidize, burn, and reduce the HC,

CO, and NOX after they leave the engine. Catalytic converters have been added to vehicles since the 1970s to help reduce tailpipe emissions. Proper converter action will take these pollutants and change them to CO 2, N2 and H2O. Refer to Figure 7.5. To do the best possible job of converting the raw exhaust gases, the internal temperature of the converter must be around 1200 to 16000 F, and the air-fuel mixture must be near the stoichiometric ratio or a bit lean. An overly rich air-fuel mixture can cause CO to be formed and also cause heat damage to the converter. You must be aware of this to ensure that it doesn’t occur.

Liquefied Petroleum Gas Training Program PAGE 7-8 Liquefied Petroleum MODULE 7: BASIC EMISSIONS AND CONTROLS Gas

Key Points & Notes a) SINGLE-BED OXIDATION CATALYST Secondary air 7-16

HC, CO Oxidation Air-fuel mixer catalyst or fuel injector

b) DUAL-BED CATALYST 7-17

HC, CO NOx reduction oxidation catalyst catalyst Air-fuel mixer or fuel injector

Secondary air c) SINGLE-BED THREE-WAY CATALYST 7-18

Electronic control unit Oxygen (lambda) sensor

NOx, HC, CO oxidation Air-fuel mixer catalyst or fuel injector

Michele Ortega 7-5 Oxidation and reactive catalysts.

Recent research on the ability of automotive 3-way catalytic converters to catalyze the exhaust stream of LPG fueled engines has revealed some important information. With current catalytic converters, it is important to understand that LPG is difficult to catalyze under normal operating circumstances. It has been suggested that the air-to-fuel ratio window for best converter efficiency on LPG vehicles is smaller than the window for gasoline fueled vehicles. In order to maintain converter efficiency, the LPG technician must make the system adjustments necessary to achieve the proper air-to-fuel ratio. There f o re, when perf o rming an emissions check and adjustment, ensure the vehicle is at normal operating temperature.

Liquefied Petroleum Gas Training Program PAGE 7-9 Liquefied Petroleum MODULE 7: BASIC EMISSIONS AND CONTROLS Gas

Converters age, and their conversion efficiency will decrease over Key Points & Notes time. Periodic inspection and adjustment of converted LPG fuel systems may be in order. This would ensure that catalytic converters will remain fully functional for their natural “useful” life. Converter aging and inefficiency might accelerate if the proper air- to-fuel ratio is not maintained. Improper mixture/distribution, ignition timing, and poor engine condition can increase emissions and premature replacement of the converter. EFFECTS OF VARIOUS FUELS AND EXHAUST GASES The amounts of propane and butane in the LPG fuel affect the exhaust emissions. Fuel composition standards for LPG motor fuel 7-19 a re being established by the propane gas industry, engine manufacturers, and regulatory agencies. The composition of LPG fuel varies by location and season. Therefore, a driver on a cross country trip in an LPG vehicle may notice a difference in performance from fill to fill, caused by change in fuel composition. Emissions will also vary. Methane is the lightest and smallest hydrocarbon molecule. Ethane, propane, and butane molecules are progressively larger. As HC molecules get larger they tend to be viscosious liquids (oils) and solids (waxes and tars). Methane, the lightest hydrocarbon, is difficult to liquefy. It is liquefied to -259o F (-162o C) and stored as a motor fuel at <150 psig. Natural gas is compressed to 3000 psi for storage as a motor fuel – as a gas. Propane and butane, on the other hand, liquefy at low pressures at room temperature. Gasoline is liquid at cool room temperature and normal atmospheric pressure. The hydrogen-to-carbon ratio lowers with larger HC molecules. For natural gas, the H-to-C ratio is 4:1; for LPG, the H-to-C ratio is slightly less than 3:1; and for heptane the H-to-C ratio is slightly more than 2:1. This explains why CO2 decreases when an engine switches from gasoline to a gaseous fuel.

The concentration reading for CO2 at the tailpipe, measured with a 4- or 5-gas analyzer, is lower for LPG and natural gas compared to gasoline. Under ideal conditions, the CO2 content in the gasoline fueled exhaust stream could yield approximately 15.3-15.8 percent. Assuming equal fuel economy on an energy equivalent basis, LPG should produce about 10 percent lower CO2 emissions than conventional gasoline vehicles.

HISTORY OF CALIFORNIA EMISSIONS STANDARDS AND THE LEV EMISSION STANDARDS Historically, California has always had higher emissions standards than the Federal standards because of its severe air pollution 7-20 problems. This has required that auto makers produce two versions of a vehicle — one to meet Federal standards and one to meet California standards. Even with the higher standards, parts of California are still in non-attainment for ozone and carbon monoxide levels. With that in mind, California has begun a program to bring low emitting vehicles (LEV) into its state fleet.

Liquefied Petroleum Gas Training Program PAGE 7-10 Liquefied Petroleum MODULE 7: BASIC EMISSIONS AND CONTROLS Gas

The LEV program sets emissions standards for three classes of Key Points & Notes vehicles and provides for a schedule of implementation rates of these vehicles into the California fleet. One other class of vehicle, the zero- emitting vehicle (ZEV), usually meaning electric vehicles, is also included in the program implementation schedule. The three classes of vehicles include the transitional low-emitting vehicle (TLEV), the low-emitting vehicle (LEV), and the ultra low-emitting vehicle (ULEV). These three classes of vehicles, along with the ZEV, will rep r esent a major portion of the new car fleet in California by the year 2003. Recently, several states in the Ozone Transport Region of the northeastern U.S. have adopted, or are attempting to adopt, the California standards for new vehicles sold in those states. The California LEV standards (in grams per mile) are as follows: TLEV LEV ULEV 7-21 NMOG 0.125 0.075 0.04 CO 3.4 3.4 1.7

NOx 0.4 0.2 0.2 Formaldehyde 0.015 0.015 0.008

California is using an NMOG (non-methane organic gases) standard instead of NMHC because NMOG includes alcohols in its makeup, and NMHC does not. As of this writing, some automakers have introduced vehicles that meet the LEV standard.

WHERE TO FIND EMISSION STANDARDS FOR YOUR LOCALITY Since clean air is such a broad topic of interest, there are many entities that will have an impact on what an LPG technician will be 7-22 doing with alternative fuel vehicles. These entities usually fall into one of three categories: • governmental agencies • environmental interest groups • business, industry, and professional organizations. It is the responsibility of the technician to be aware of which agency or organization will regulate or influence the work performed. The following list is suggested as a starting point: • State and local Departments of Health (health regulations); • State and local Departments of Natural Resources (environmental regulations); • State and local Departments of Transportation (vehicle codes); • State and local Fire Protection Departments (refueling facility codes); • National Fire Protection Association (NFPA) (vehicular fuel system codes); and/or • National Propane Gas Association (NPGA).

Liquefied Petroleum Gas Training Program PAGE 7-11 Liquefied Petroleum MODULE 7: BASIC EMISSIONS AND CONTROLS Gas

Key Points & Notes

7-24

AIR INTAKE

P.C.V. VALVE

P.C.V. SYSTEM

Air

High Rev. Blowby

Low Rev. Blowby

Peter Aschwanden

Spring 7-25

From To Intake Crankcase

Valve Courtesy of OTC

7- 6 Positive crankcase ventilation system

Liquefied Petroleum Gas Training Program PAGE 7-12 Liquefied Petroleum MODULE 7: BASIC EMISSIONS AND CONTROLS Gas

DEVELOPMENT OF EMISSION CONTROL SYSTEMS Key Points & Notes Emission control legislation in the mid 1960’s spurred engineers to gain control over the stoichiometry process. While controlling 7-23 emissions has progressed, it continues to evolve as more stringent legislation is passed. The first steps toward reducing emissions was the use of a positive crankcase ventilation system (PCV). These were made on light duty automobiles. Heavy duty emission controls are currently being introduced. This simple component allowed blowby gases from the crankcase, heavily laden with raw hydrocarbons, to be drawn back into the engine through a small valve in the valve cover or intake manifold. These blowby gases were further reduced with impro v e d manufacturing processes and better engine materials. Later, the exhaust gas recirculation valve (EGR) was developed. The EGR valve bleeds a small amount of the exhaust gases into the combustion chamber. This exhaust gas dilutes the air-fuel mixture to reduce the peak combustion temperatures and NOX emissions. Refer to Figure 7-7. The catalytic converter is an emission control device that was introduced in 1975 on all American-made cars. The early catalytic 7-27 converters were simply canisters filled with platinum and palladium coated pellets that react under high temperatures (600o – 750o F) to convert CO into carbon dioxide (CO2). This process was further improved by the addition of an air pump to supply an adequate supply of air to bond with the CO to make CO2. The catalytic converter is usually placed upstream of the muffler. The catalyst promotes reaction between HC, CO, O2, converting these gases into CO2 and H2O. When exhaust gases react with the catalyst, temperatures in the converter reach 1300o–1600o F. Oxidation catalysts are operated with the mixture set lean or by adding air to reduce (oxidize) CO and HC. Reduction catalysts

EGR Vacuum Regulator Solenoid 7-26 (shown closed) EVP Filtered Bleed to Sensor Atmosphere

EGR Valve Assembly

As duty cycle to the EGR Vacuum Regulator Solenoid increases, vacuum to the EGR To Manifold Valve increases and Vacuum opens valve more

7-7 Exhaust gas rec i r culation valve.

Liquefied Petroleum Gas Training Program PAGE 7-13 Liquefied Petroleum MODULE 7: BASIC EMISSIONS AND CONTROLS Gas operate with a slightly rich mixture (without added air) to reduce Key Points & Notes NOx. Dual-bed catalysts incorporate a reduction catalyst upstream of an oxidation catalyst; the two “cats” are housed in one unit. The engine is run on a slightly rich mixture to operate the reduction catalyst to catalyze NOx. Air is added downstream, above the secondary bed, to reduce CO and HC. The major problem with the reduction and dual-bed catalyst is that the engine must be adjusted rich to operate it, resulting in poor fuel economy. Emissions reduction was further improved with the development of th r ee-bed catalysts, which use platinum, rhodium, and palladium. The most common applications now have replaced the old pelleted converters. The three-way or selective catalyst operates with a closed loop, oxygen sensor feedback fuel control system. The engine must run at or close to stoichiometry to operate the three-way catalyst.

O2 sensor feedback electronic fuel injection along with the catalytic converter are the two most important developments responsible for 7-28 reducing emissions. UNDERSTANDING FEEDBACK SYSTEMS The fundamental operation of computerized engine control is actually quite simple. The computer, also called the power control module 7-29 (PCM), takes information from various sensors to relay data on cu r r ent engine operations and uses this data to control output actuators to keep the engine within pre- p r ogrammed operating boundaries. This operation is called closed loop fuel control. The closed loop refers to the rec u r r ent process of transferring informa t i o n fr om sensor to PCM to actuator and back to combustion. This cycle takes place at speeds in excess of 5-25 times a second. The PCM is capable of controlling the engine’s operations very accurately, keeping performance high and emissions and fuel consumption low. The system allows the PCM to constantly evaluate engine operation and optimize engine performance for each given moment by evaluating input from sensors, processing data, giving actuator commands, and monitoring again for results before making another change. This is a very efficient system that must be left intact and operational when the engine is converted to propane. Refer to Figure 7-8.

INPUT SENSORS Numerous sensors are used on modern engines, but not all engines have the same sensors. 7-30 Only those sensors common to most engines will be discussed here. Most of these sensors work in a similar way – relaying information pertaining to some facet of engine operation to the PCM via electrical signals. These signals are usually low voltage (5 volts or less) or a frequency measured in hertz. BARO or Barometric Pressure Sensor This sensor determines the atmospheric pressure to enable the PCM to compare it to manifold pressure and calculate air flow into the engine. When the PCM is first energized prior to startup, the

Liquefied Petroleum Gas Training Program PAGE 7-14 Liquefied Petroleum MODULE 7: BASIC EMISSIONS AND CONTROLS Gas

Courtesy of Mitchell 7- 8 Power Control Module and related circu i t r y. 7-31 BARO references altitude and ambient atmospheric pressure. The PCM also calculates engine load by comparing the difference between the BARO and MAP sensor. Some of the newer vehicles, however, perform both tasks with only a MAP sensor. The BARO is usually a variable resistor network-type sensor. VBAT or Battery Voltage Sensor This sensor allows the PCM to determine if sufficient voltage is present for the system and to control the voltage output from the charging system. It also isolates the sensitive electronics from harmful voltage spikes. CTS or Coolant Temperature Sensor The CTS is a resistor that changes value by temperature. CTS input voltage is high when the engine is cold and low when hot. This information is critical for proper fuel and ignition control. ECT or Engine Coolant Temperature Sensor This sensor uses variable resistance draw against a reference voltage from the PCM to calculate block temperature and allow the PCM to go into closed loop operation, generally around 195o F. A high resistance indicates low temperature, and a low resistance indicates a high temperature. This is a thermistor or thermal resistor-type sensor.

IAT or Intake Air Temperature Sensor The IAT input tells the PCM to retard timing when intake air is hot.

Liquefied Petroleum Gas Training Program PAGE 7-15 Liquefied Petroleum MODULE 7: BASIC EMISSIONS AND CONTROLS Gas

This controls Nox emissions and prevents Key Points & Notes detonation or pinging. Refer to Figure 7-9.

PIP or Profile Ignition Pickup 7-32 Sometimes called distributor re f e re n c e , the PCM uses the signal from this sensor to determine the relative position of the Courtesy of IMPCO crankshaft during rotation to locate top 7- 9 IA T se n s o r . dead center for ignition timing. Most systems without a distributor use this reference to simulate a Tachometer signal. The signal generated is usually a 5 to 12 volt square wave. The PIP incorporates a hall effect sensor.

EVP or EGR Valve Position Sensor The PCM uses this sensor to determine the amount of travel in the EGR system, which is controlled by engine vacuum. This way the PCM can control the amount of EGR gas bypass to the intake manifold via a vacuum solenoid. This is a potentiometer-type sensor.

7-33

Courtesy of OTC

7-10 Common input sensor (02 se n s o r ) .

HEGO/EGO or Exhaust Gas Oxygen Sensor (O2 Sensor) The HEGO/EGO sensor tells the PCM that there is or isn’t oxygen present in the exhaust. It senses whether the exhaust gas is rich or lean. Once it reaches a temperature of 600o F, the sensor generates a voltage signal between 0.00 volts and 1.0 volts for the PCM to interpret. Above 0.50 volts is a “rich” signal, and below 0.50 volts is a “lean” signal. The exhaust of an engine running at stoichiometry generates an O2 sensor signal of about 0.48 volts for gasoline and 0.46 volts for propane. An EGO is the standard sensor; a HEGO is a heated sensor, which starts its signal sooner. This thermal generator-type sensor is the key sensor in “closed loop” fuel control. Refer to Figure 7-10.

MAF or Mass Air Flow Sensor 7-35 The MAF tells the PCM the amount – mass or weight – of air entering the engine. MAF is incorporated in an engine management system in pl a c e of MAP. See MAP below. Refer to Figure 7-11. MAP or Manifold Absolute Pressure Sensor The PCM uses this input to help calculate the Courtesy of IMPCO airflow rate and mass of air entering the engine. 7-11 MAF sensor. 7-34 The MAP sensor senses engine load as manifold

Liquefied Petroleum Gas Training Program PAGE 7-16 Liquefied Petroleum MODULE 7: BASIC EMISSIONS AND CONTROLS Gas

“vacuum” changes in relation to atmospheric Key Points & Notes pressure. This is a variable resistor network- type sensor. An engine management system that uses a MAP sensor is called a “speed 7-36 density” system. Refer to Figure 7-12.

MAT/ATS or Manifold Air Temperature Sensor The PCM uses this sensor to determine the temperature of the air being consumed by the engine and can calculate the density of the air Courtesy of from its temperature. The cooler the air, the Autotronic Controls more dense it is; the denser the air, the more 7-12 MAP sensor. fuel re q u i red. The PCM also uses this information to control timing and EGR. This is a thermistor or thermal resistor-type sensor.

ESC or Knock Sensor The PCM uses this sensor to control the ignition timing. This sensor uses a crystal disc that is sensitive to the frequencies generated when an engine detonates. If the frequency is between 5.0 to 6.5 kHz, the sensor generates a voltage signal to the PCM, which retards timing. This is a piezoelectric voltage generator.

TPS or Throttle Position Sensor The PCM uses this sensor to d e t e rmine the position of the 7-37 t h rottle. This is important to calculate fuel mixtures, timing, TBI etc. This potentiometer- t y p e sensor sends a variable voltage signal from 1.0-5.0 volts to indicate position.

Other Sensors (Signals) TPS These include air conditioner co n t r ol signal, transmission gear Courtesy of position signal, power steering Autotronic Controls pre s s u r e switch, crank signal and inputs related to self-diagnostics. 7-13 Th r ottle position sensor. See OBD I and II below.

OUTPUT ACTUATORS The computer, having evaluated the data received from the input sensors, processes the information and commands the various 7-38 actuators to change the performance of the engine. The most important and common of these actuators follow:

ACC (Air Conditioner Clutch Control) The PCM uses this switch to engage or disengage the air conditioner (A/C) clutch when the engine is under load conditions or other unique driving conditions. Some newer passenger cars actually use the A/C clutch to control idle speed on cold engines by toggling the co m p re s s o r .

Liquefied Petroleum Gas Training Program PAGE 7-17 Liquefied Petroleum MODULE 7: BASIC EMISSIONS AND CONTROLS Gas

CANP (Canister Purge Solenoid) Key Points & Notes The CANP is an electromagnetical solenoid that is controlled by the PCM. The CANP ports fuel vapors from the gasoline tank into the intake at controlled engine loads, speeds, and temperatures.

EGR (Exhaust Gas Recirculation)

This valve, designed to control NOx emissions, allows exhaust gas to be introduced (ported) into the intake manifold. A temperature or el e c t r onically operated device controls when and how much vacuum gets to the EGR valve.

ESC (Electronic Spark Control) This is the module that the PCM uses to control ignition timing advance. This is controlled by data from the TPS, MAP, and knock sensors.

IAC/IAB (Idle Air Bypass/Control)

The PCM controls the idle Intake Air speed by allowing air to by- Control Actuator 7-39 pass the throttle. The system uses a small stepper motor assembly to control a variable orifice for passing air from above to below throttle. The idle air speed is c o n t rolled to provide a consistent, stable idle throughout the life of the engine. This ensures the Throttle lowest possible emissions Courtesy of IMPCO Position Sensor and fuel consumption. Idle 7-14 Throttle assembly with IAC and speed is also controlled to TPS support loads on the engine, such as air conditioning.

MPFI/TBI (Fuel Injectors) These are typically solenoid operated pintle valves that the PCM uses to introduce fuel into the intake manifold. The amount of fuel supplied is controlled by the open time or “pulse width” of the valve. The fuel is supplied to the intake manifold at a relatively constant pressure and the PCM opens the injector for a longer or shorter period to enrich or lean the mixture of fuel and air. A TBI system (Throttle Body Injection) uses a single or dual injector assembly to spray fuel above the throttle plate assembly, whereas a MPFI system (Multi-Point Fuel Injection) uses multiple injector fuel assemblies to spray fuel into the intake manifold, right at the intake valves. The two common MPFI methods are bank and sequential injection. Refer to Figure 7-8.

Other Outputs Depending on the engine make and application, the PCM controls numerous actuators and components such as cooling fan(s), fuel 7-41

Liquefied Petroleum Gas Training Program PAGE 7-18 Liquefied Petroleum MODULE 7: BASIC EMISSIONS AND CONTROLS Gas

SENSOR INPUTS AC T U AT O R Key Points & Notes Coolant Temperature OU T P U T S Manifold Absolute Air/Fuel Mixture 7-40 Pressure Ignition Timing Barometric Pressure PO W E RT R A I N Idle Speed Crankshaft Position Canister Purge Engine Speed Turbocharger Boost Exhaust Gas Oxygen CO N T R O L Exhaust Gas Throttle Position Recirculation Spark Knock Fuel Pump Relay MO D U L E Mass Air Flow Engine Cooling Fan Air Charge Air Injection Pump Temperature Air Flow Exhaust Gas Air Inlet Temperature Recirculation Larry DaShiell 7-15 Sensor Iinputs/Actuator outputs (not all used in all systems). pump, and a variety of diagnostic tests involving some of the above actuators and controls. Learning the components on the vehicle that you work on is important. Refer to appropriate service manuals and bulletins.

OBD I and II All vehicles sold in California in 1988 had to have limited diagnostic capability — known as OBD I. This gave birth to the MIL (Malfunction Indicator Light) or Check Engine/Service Engine Soon Light, which indicated a problem recognized by the PCM. OBD I soon became standard on all new vehicles sold in the U.S. In 1994 some, and by 1996, all vehicles will have additional diagnostic capability that will monitor transmission control system including the EGR system, O2 sensor, catalytic converter efficiency, misfire detection, fuel system monitor and overall system component monitoring

Vacuum Switches The PCM uses these valves to control functions like EGR, vacuum advance, canister purge, etc. These are simple solenoid-operated vacuum control valves.

Liquefied Petroleum Gas Training Program PAGE 7-19 Liquefied Petroleum MODULE 7: BASIC EMISSIONS AND CONTROLS Gas

MODULE REVIEW ITEMS

Note to Technician: Consider all choices carefully and select the best answer to each. 1. What was the first Federal emissions standards that auto manufacturers had to meet in order to sell vehicles to the US public? A. Clean Air Act of 1963. B. Clean Air Act Amendments of 1968. C. California Low Emitting Vehicles (LEV) Program. D. None of the above.

2. Which three pollutants has the Environmental Protection Agency (EPA) identified as hazardous to human health and the environment? A. O2, CO, and NO X. B. THC, N2, and CO. C. THC, CO, and NOX. D. CO 2, H2O, and HC.

3. What are pollutants emitted from motor vehicles are usually measured in? A. Grams/mile (gpm). B. Parts/million (ppm). C. Mass of CO. D. None of the above.

4. When unburned hydrocarbons are not oxidized in the combustion process; it can be the result of _____. A. Engine misfiring. B. Poor fuel/air mixing. C. Excessively rich air-fuel mixture. D. All of the above.

5. What is the primary reason(s) that unburned hydrocarbons are regulated? A. Some hydrocarbons are considered carcinogenic and damaging to health. B. Many are photochemically reactive in the atmosphere and damaging to the environment. C. A & C. D. None of the above.

6. It has been found that LPG vehicle THC emissions are all reactive. A. True. B. False.

7. What type of emissions are the result of incomplete combustion of the air-fuel mixture or a rich mixture in the combustion chamber? A. NO X. B. CO. C. CO2. D. O2.

Liquefied Petroleum Gas Training Program PAGE 7-20 Liquefied Petroleum MODULE 7: BASIC EMISSIONS AND CONTROLS Gas

8. Incomplete combustion is caused by the poor mixing of the air and fuel in the combustion chamber, or lack of _____ in the air-fuel mixture. A. NO X. B. CO. C. CO2. D. O2.

9. Nitrogen provides no benefit to combustion. A. True. B. False.

10. A high oxygen percentage (on a 4 or 5 gas analyzer) means the air/fuel ratio is _____. A. Rich. B. Lean.

11. Complete the following combustion reaction: Fuel + Oxidizer = ? A. Air/fuel ratios. B. Combustion products. C. Exhaust gases. D. None of the above.

12. The catalytic converter provides an additional area to oxidize, burn and reduce what pollutants after they leave the engine? A. HC. B. CO. C. NO x. D. All of the above.

13. Proper catalytic converter action will take the pollutants and change them to _____. A. CO 2. B. N2. C. H2O. D. All of the above.

14. An overly rich air/fuel mixture can cause _____ to be formed and also cause heat damage to the catalytic converter. A. HC. B. CO. C. NOx. D. N2.

15. Why is it important to ensure an LPG vehicle is at normal operating temperature when performing an emissions check? A. To ensure the proper air/fuel ratio. B. An overly rich mixture can cause heat damage to the converter. C. Because LPG is difficult to catalyze under normal operating circumstances. D. None of the above.

16. Catalytic converters age, and their conversion efficiency will decrease over time. A. True. B. False.

Liquefied Petroleum Gas Training Program PAGE 7-21 Liquefied Petroleum MODULE 7: BASIC EMISSIONS AND CONTROLS Gas

17. The composition of LPG fuel can vary by location and season. A. True. B. False.

18. Where can you find emission standards for your area? A. Governmental agencies. B. Environmental interest groups. C. Business, industry and professional organizations. D. All of the above.

19. Which of the following were developed as part of emission control systems? A. Positive crankcase ventilation system (PCV). B. Exhaust gas recirculation valve (EGR). C. Catalytic converter. D. All of the above.

20. Which description best explains the operation of a catalytic converter? A. It allows gases to be drawn back into the engine through a small valve in the valve cover or intake manifold to reduce emissions. B. It bleeds a small amount of the exhaust gases into the combustion chamber to reduce emissions. C. A canister placed upstream of the muffle to promote reaction between HC, CO, and O2. D. None of the above.

21. What is the most common style of converter now used? A. Pelleted converters. B. Three bed catalysts. C. Oxidation catalysts. D. Reduction catalysts.

22. What are the two most important components responsible for reducing emissions? A. O2 sensor feedback system and the exhaust recirculation valve (EGR). B. Positive crankcase ventilation system (PCV) and exhaust recirculation valve (EGR). C. The catalytic converter and the O2 sensor feedback system. D. The catalytic converter and the three bed catalysts.

23. What does closed loop fuel control refer to? A. The recurrent process of transferring information from sensor to power control module (PCM) to actuator and back to combustion. B. Taking information from various sensors to relay data about current engine conditions. C. Its ability to control the engine's operation very accurately. D. None of the above.

24. The Barometric Pressure Sensor (BARO), the Coolant Temperature Sensor (CTS) and the Intake Air Temperature Sensor (IAT) are all _____. A. Output actuators. B. Vacuum switches. C. Input sensors. D. All of the above.

Liquefied Petroleum Gas Training Program PAGE 7-22 Liquefied Petroleum MODULE 7: BASIC EMISSIONS AND CONTROLS Gas

25. The Canister Purge Solenoid (CANP), the Exhaust Gas Recirculation (EGR), and the Fuel Injectors (MPFI/TBI) are all _____. A. Output actuators. B. Vacuum switches. C. Input sensors. D. All of the above.

Liquefied Petroleum Gas Training Program PAGE 7-23 Liquefied Petroleum MODULE 7: BASIC EMISSIONS AND CONTROLS Gas

MRI SCORING KEY

1. B 2. C 3. A 4. D 5. C 6. B 7. B 8. D 9. A 10. B 11. B 12. D 13. D 14. B 15. A 16. A 17. A 18. D 19. D 20. C 21. B 22. C 23. A 24. C 25. A

Liquefied Petroleum Gas Training Program

1 MODULE 7: Basic Emissions and Controls 2 HISTORY & ORIGINATION OF VEHICLE EMISSION STANDARDS • First pollution studies in LA – Damage to health and environment • Regulation of particulates in 1948 • Motor vehicles cited as pollutants • Federal regulation since 1955 3 HISTORY & ORIGINATION OF VEHICLE EMISSION STANDARDS • Clean Air Act of 1963 • Clean Air Act Amendments of 1968 and 1992 4 7-1 SIXTY YEARS OF LA SMOG 5 EMISSIONS OF CONCERN • Total hydrocarbons (THC) • Carbon monoxide (CO)

• Nitrogen oxides (NOx) 6 UNBURNED HYDROCARBONS (HC) • Unburned Hydrocarbons (HC) – Hydrogen and carbon compounds – Not oxidized in the combustion process – Result of engine misfiring or poor fuel/air mixing • The need for regulation: – Health hazards – Photochemically reactive – Ozone – Smog 7 UNBURNED HYDROCARBONS (HC) • Unburned hydrocarbons are separated into three categories: – Total hydrocarbons (THC) – Reactive hydrocarbons – Non-reactive hydrocarbons

8 UNBURNED HC, THC, AND OTHERS • Gasoline Total HC: – 100% Reactive • LPG Total HC: – 60% Reactive 9 CARBON MONOXIDE (CO) • Carbon Monoxide (CO) – Colorless and odorless gas • CO is a result of: – Incomplete combustion of the air-fuel mixture

– Lack O 2 in the combustion chamber – Restricted air induction system

10 OXIDES OF NITROGEN (NOX)

• Nitrogen Oxides (NOx) pollutants include: – NO- Nitric Oxide

– NO2 - Nitrogen Dioxide

– NO3 - Nitrous Oxide – Others • (NOx) pollutants cause: – Irritations to the eyes and respiratory system – Photochemical smog and acid rain

11 OXIDES OF NITROGEN (NOX) • Nitrogen oxides are formed in the combustion process when combustion temperature is high – Sensitive to air-fuel ratio – Affected by excessive timing advance – Peak production occurs when HC and CO production are low and combustion is good 12 7-3 EXHAUST GAS EMISSION CONTROL 13 EVAPORATIVE EMISSIONS • Carcinogenic and photochemically reactive • The fuel system must be totally sealed • Leak detection is recommended • Newer LPG tanks close off the LPG filling process automatically, reducing evaporative emissions significantly 14 7-4 REFUELING EMISSIONS 15 AIR/FUEL RATIOS AND EXHAUST GASES • Fuel + Oxidizer = Combustion Products • Catalytic Converter Reactions

– Burns, and reduces the HC, CO and NOX

– Change to CO2, N2, and H2O • Optimal Conditions: – Internal temperature of the converter - 12000 to 16000 F – Air/fuel mixture near the stoichiometric ratio 16 7-5A SINGLE-BED CATALYST 17 7-5B DUAL-BED CATALYST 18 7-5C SINGLE-BED THREE-WAY CATALYST 19 EFFECTS OF VARIOUS FUELS AND EXHAUST GASES • Fuel standards for LPG as a motor fuel • Hydrogen:carbon ratio vs. larger HC molecules

• CO2 content in gasoline emissions: 15.3-15.8%

• CO2 content in LPG emissions: 10% lower 20 HISTORY OF CALIFORNIA EMISSIONS STANDARDS AND THE LEV EMISSIONS STANDARDS • CA higher emissions standards than Federal standards • Parts of CA are still in the nonattainment for ozone and carbon monoxide levels • CA low emitting vehicles (LEV) program • LEV program standards for 3 classes of vehicles – Transitional low-emitting vehicle (TLEV) – Low-emitting vehicle (LEV) – Ultra low-emitting vehicle (ULEV) 21 HISTORY OF CALIFORNIA EMISSIONS STANDARDS AND THE LEV EMISSIONS STANDARDS • CA LEV standards (grams/mile):

TLEV LEV ULEV NMOG 0.125 0.075 0.04 CO 3.4 3.4 1.7

NOX 0.4 0.2 0.2 Formaldehyde 0.015 0.015 0.008 22 WHERE TO FIND EMISSION STANDARDS FOR YOUR LOCALITY • Government agencies • Environmental interest groups • Business, industry and professional organizations 23 DEVELOPMENT OF EMISSION CONTROL SYSTEMS • Positive crankcase ventilation system (PVC) • Exhaust gas recirculation valve (EGR) • Catalytic converter (reactor) 24 7-6A PCV SYSTEM

25 7-6B PCV SYSTEM 26 7-7 EXHAUST GAS RECIRCULATION VALVE

27 DEVELOPMENT OF EMISSION CONTROL SYSTEMS • Catalytic converters • Oxidation catalysts – Adds air to reduce (oxidize) CO and HC • Reduction catalyst

– Operate in a rich mixture to reduce NOx • Three bed catalysts – Use platinum, rhodium and palladium 28 DEVELOPMENT OF EMISSION CONTROL SYSTEMS • The two most important components responsible for reducing emissions – Catalytic converter

– O2 sensor feedback electronic fuel injection 29 UNDERSTANDING FEEDBACK SYSTEMS • Power Control Module (PCM) – Closed loop fuel control – Constantly evaluates engine operation and optimizes engine performance – Must be left intact and operational when the engine is converted to propane 30 INPUT SENSORS • BARO or Barometric Pressure Sensor • VBAT or Batter Voltage Sensor • CTS or Coolant Temperature Sensor • ECT or Engine Coolant Temperature Sensor • IAT or Intake Air Temperature Sensor • PIP or Profile Ignition Pickup • EVP or EGR Valve Position Sensor • HEGO/EGO or Exhaust Gas Oxygen Sensor 31 7-8 POWER CONTROL MODULE 32 7-9 IAT SENSOR

33 7-10 O2 SENSOR 34 INPUT SENSORS • MAF or Mass Air Flow Sensor • MAP or Manifold Absolute Pressure Sensor • MAT/ATS or Manifold Air Temperature Sensor • ESC or Knock Sensor • TPS or Throttle Position Sensor • Other Sensors (Signals) 35 7-11 MAF SENSOR

36 7-12 MAP SENSOR 37 7-13 THROTTLE POSITION SENSOR 38 OUTPUT ACTUATORS • ACC or Air Conditioner Control • CANP or Canister Purge Solenoid • EGR or Exhaust Gas Recirculation • ESC or Electronic Spark Control • EVR or Electronic Vacuum Regulator Solenoid • IAC/IAB or Idle Air Bypass/Control • MPFI/TBI or Fuel Injectors 39 7-14 THROTTLE ASSEMBLY 40 7-15 SENSOR INPUTS/ACTUATOR OUTPUTS 41 OTHER OUTPUT ACTUATORS • Other Actuators • OBD I and II • Vacuum switches MODULE 7: Basic Emissions and Controls

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 7-1

HISTORY & ORIGINATION OF VEHICLE EMISSION STANDARDS

• First pollution studies in LA – Damage to health and environment • Regulation of particulates in 1948 • Motor vehicles cited as pollutants • Federal regulation since 1955

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 7-2

HISTORY & ORIGINATION OF VEHICLE EMISSION STANDARDS

• Clean Air Act of 1963 • Clean Air Act Amendments of 1968 and 1992

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 7-3

7-1 SIXTY YEARS OF LA SMOG

1936 1966 1996

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 7-4

EMISSIONS OF CONCERN

• Total hydrocarbons (THC) • Carbon monoxide (CO)

• Nitrogen oxides (NOx)

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 7-5

UNBURNED HYDROCARBONS (HC)

• Unburned Hydrocarbons (HC) – Hydrogen and carbon compounds – Not oxidized in the combustion process – Result of engine misfiring or poor fuel/air mixing • The need for regulation: – Health hazards – Photochemically reactive – Ozone – Smog

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 7-6

UNBURNED HYDROCARBONS (HC)

• Unburned hydrocarbons are separated into three categories: – Total hydrocarbons (THC) – Reactive hydrocarbons – Non-reactive hydrocarbons

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 7-7

UNBURNED HC, THC, AND OTHERS

• Gasoline Total HC: – 100% Reactive • LPG Total HC: – 60% Reactive

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 7-8

CARBON MONOXIDE (CO)

• Carbon Monoxide (CO) – Colorless and odorless gas • CO is a result of: – Incomplete combustion of the air-fuel mixture

– Lack O2 in the combustion chamber – Restricted air induction system

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 7-9

OXIDES OF NITROGEN (NOX)

• Nitrogen Oxides (NOx) pollutants include: – NO- Nitric Oxide

– NO2 - Nitrogen Dioxide

– NO3 - Nitrous Oxide – Others

• (NOx) pollutants cause: – Irritations to the eyes and respiratory system – Photochemical smog and acid rain

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 7-10

OXIDES OF NITROGEN (NOX)

• Nitrogen oxides are formed in the combustion process when combustion temperature is high – Sensitive to air-fuel ratio – Affected by excessive timing advance – Peak production occurs when HC and CO production are low and combustion is good

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 7-11

7-3 EXHAUST GAS EMISSION CONTROL

Stoichiometric range of the catalyst (window) Lambda

NOX

HC CO

UPSTREAM OF 3-WAY CAT

NOX HC

DOWNSTREAM OF 3-WAY CAT John Hilgerdt

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 7-12

EVAPORATIVE EMISSIONS

• Carcinogenic and photochemically reactive • The fuel system must be totally sealed • Leak detection is recommended • Newer LPG tanks close off the LPG filling process automatically, reducing evaporative emissions significantly

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 7-13

7-4 REFUELING EMISSIONS

Photo Copyright Harris Fogel

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 7-14

AIR/FUEL RATIOS AND EXHAUST GASES

• Fuel + Oxidizer = Combustion Products • Catalytic Converter Reactions

– Burns, and reduces the HC, CO and NOX

– Change to CO2, N2, and H2O • Optimal Conditions: – Internal temperature of the converter - 12000 to 16000 F – Air/fuel mixture near the stoichiometric ratio

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 7-15

7-5A SINGLE-BED CATALYST

a) SINGLE BED OXIDATION CATALYST Secondary air

HC, CO Oxidation Air-fuel mixer catalyst or fuel injector

Michele Ortega College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 7-16

7-5B DUAL-BED CATALYST

b) DUAL-BED CATALYST

NOX HC, CO reduction oxidation Air-fuel mixer catalyst catalyst or fuel injector

Secondary air

Michele Ortega

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 7-17

7-5C SINGLE-BED THREE-WAY CATALYST

c) SINGLE-BED THREE-WAY CATALYST

Electronic control unit Oxygen (lambda) sensor

NOX, HC, CO oxidation Air-fuel mixer catalyst or fuel injector

Michele Ortega

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 7-18

EFFECTS OF VARIOUS FUELS AND EXHAUST GASES

• Fuel standards for LPG as a motor fuel • Hydrogen:carbon ratio vs. larger HC molecules

• CO2 content in gasoline emissions: 15.3-15.8%

• CO2 content in LPG emissions: 10% lower

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 7-19

HISTORY OF CALIFORNIA EMISSIONS STANDARDS AND THE LEV EMISSIONS STANDARDS

• CA higher emissions standards than Federal standards • Parts of CA are still in the nonattainment for ozone and carbon monoxide levels • CA low emitting vehicles (LEV) program • LEV program standards for 3 classes of vehicles – Transitional low-emitting vehicle (TLEV) – Low-emitting vehicle (LEV) – Ultra low-emitting vehicle (ULEV)

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 7-20

HISTORY OF CALIFORNIA EMISSIONS STANDARDS AND THE LEV EMISSIONS STANDARDS

• CA LEV standards (grams/mile):

TLEV LEV ULEV NMOG 0.125 0.075 0.04 CO 3.4 3.4 1.7

NOX 0.4 0.2 0.2 Formaldehyde 0.015 0.015 0.008

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 7-21

WHERE TO FIND EMISSION STANDARDS FOR YOUR LOCALITY

• Government agencies • Environmental interest groups • Business, industry and professional organizations

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 7-22

DEVELOPMENT OF EMISSION CONTROL SYSTEMS

• Positive crankcase ventilation system (PVC) • Exhaust gas recirculation valve (EGR) • Catalytic converter (reactor)

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 7-23

7-6A PCV SYSTEM

AIR INTAKE

PCV VALVE

PCV SYSTEM Air High Rev. Blowby Low Rev. Blowby

Peter Aschwanden

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 7-24

7-6B PCV SYSTEM

Courtesy of OTC

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 7-25

7-7 EXHAUST GAS RECIRCULATION VALVE

Courtesy of OTC

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 7-26

DEVELOPMENT OF EMISSION CONTROL SYSTEMS

• Catalytic converters • Oxidation catalysts – Adds air to reduce (oxidize) CO and HC • Reduction catalyst

– Operate in a rich mixture to reduce NOx • Three bed catalysts – Use platinum, rhodium and palladium

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 7-27

DEVELOPMENT OF EMISSION CONTROL SYSTEMS

• The two most important components responsible for reducing emissions – Catalytic converter

– O2 sensor feedback electronic fuel injection

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 7-28

UNDERSTANDING FEEDBACK SYSTEMS

• Power Control Module (PCM) – Closed loop fuel control – Constantly evaluates engine operation and optimizes engine performance – Must be left intact and operational when the engine is converted to propane

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 7-29

INPUT SENSORS

• BARO or Barometric Pressure Sensor • VBAT or Batter Voltage Sensor • CTS or Coolant Temperature Sensor • ECT or Engine Coolant Temperature Sensor • IAT or Intake Air Temperature Sensor • PIP or Profile Ignition Pickup • EVP or EGR Valve Position Sensor • HEGO/EGO or Exhaust Gas Oxygen Sensor

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 7-30

7-8 POWER CONTROL MODULE

Courtesy of Mitchell

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 7-31

7-9 IAT SENSOR

Courtesy of IMPCO

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 7-32

7-10 O2 SENSOR

Courtesy of OTC

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 7-33

INPUT SENSORS

• MAF or Mass Air Flow Sensor • MAP or Manifold Absolute Pressure Sensor • MAT/ATS or Manifold Air Temperature Sensor • ESC or Knock Sensor • TPS or Throttle Position Sensor • Other Sensors (Signals)

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 7-34

7-11 MAF SENSOR

Courtesy of IMPCO

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 7-35

7-12 MAP SENSOR

Courtesy of Autotronic Controls

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 7-36

7-13 THROTTLE POSITION SENSOR

TBI

TPS

Courtesy of Autotronic Controls

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 7-37

OUTPUT ACTUATORS

• ACC or Air Conditioner Control • CANP or Canister Purge Solenoid • EGR or Exhaust Gas Recirculation • ESC or Electronic Spark Control • EVR or Electronic Vacuum Regulator Solenoid • IAC/IAB or Idle Air Bypass/Control • MPFI/TBI or Fuel Injectors

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 7-38

7-14 THROTTLE ASSEMBLY

Intake Air Control Actuator

Throttle Position Sensor

Courtesy of IMPCO

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 7-39

7-15 SENSOR INPUTS/ACTUATOR OUTPUTS

SENSOR INPUTS ACTUATOR OUTPUTS

Coolant Temperature Air/Fuel Mixture Manifold Absolute Pressure Ignition Timing Barometric Pressure POWERTRAIN Idle Speed Crankshaft Position Canister Purge Engine Speed Turbocharger Boost CONTROL Exhaust Gas Oxygen Exhaust Gas Recirculation Throttle Position Fuel Pump Relay Spark Knock MODULE Engine Cooling Fan Mass Air Flow Air Injection Pump Air Charge Temperature Air Flow Exhaust Gas Recirculation Air Inlet Temperature

Larry DaShiell

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 7-40

OTHER OUTPUT ACTUATORS

• Other Actuators • OBD I and II • Vacuum switches

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 7-41

MODULE 8: LPG Fuel System Overview

State of Oklahoma College of the Desert West Virginia University

Liquefied Petroleum MODULE 8: LPG FUEL SYSTEM OVERVIEW Gas

CONTENTS

OBJECTIVES...... 8-i INSTRUCTOR NOTES ...... 8-ii FUEL TANKS AND TANK STANDARDS ...... 8-1 GUARD PLATE...... 8-3 SELECTING THE RIGHT DESIGN AND SIZE OF FUEL TANK...... 8-3 FUEL TANK INSTALLATION IN ENCLOSED COMPARTMENTS...... 8-4 PROPANE VALVES...... 8-5 PRESSURE RELIEF VALVE...... 8-5 FILL VALVE...... 8-6 80 PERCENT FIXED LIQUID LEVEL GAUGE...... 8-7 PROPANE LIQUID SERVICE/SHUTOFF VALVE...... 8-8 VAPOR SERVICE VALVE...... 8-9 FUEL GAUGE...... 8-9 FUEL LINES, LOCKS AND FILTERS...... 8-10 FUEL LINES...... 8-10 PIPE AND TUBING...... 8-10 HOSE...... 8-11 FITTINGS...... 8-12 HYDROSTATIC RELIEF VALVE...... 8-12 BULKHEAD FITTINGS...... 8-13 FUEL LOCK AND AUTOMATIC SHUT-OFF VALVE...... 8-13 FUEL FILTERS...... 8-14 CONVERTER VAPORIZER-REGULATOR ...... 8-14 LIQUID TO VAPOR...... 8-14 PRIMERS...... 8-17 VAPOR HOSE ...... 8-17 AIR FUEL MIXERS...... 8-18

Liquefied Petroleum Gas Training Program Liquefied Petroleum MODULE 8: LPG FUEL SYSTEM OVERVIEW Gas

FUEL METERING THEORY...... 8-18 AIR-VALVE MIXERS...... 8-18 VENTURI PRINCIPLE MIXERS...... 8-20 FUEL SWITCHING AND MONITORING COMPONENTS...... 8-20 TIMING ADAPTATION COMPONENTS ...... 8-20 LPG CLOSED LOOP FEEDBACK SYSTEMS ...... 8-22 COLD START ...... 8-22 STABILIZED ENGINE CLOSED LOOP OPERATION...... 8-23 ELECTRONIC CONVERSION SUPPORT MODULES...... 8-24 PROPANE FUEL INJECTION...... 8-26 FUEL INJECTION SYSTEM OVERVIEW ...... 8-26 MODULE REVIEW ITEMS...... 8-29 MRI SCORING KEY...... 8-39 ACTIVITY 8-1: DATA PLATE INFORMATION ACTIVITY 8-2: REGULATOR PRESSURE/VOLUME RELATIONSHIPS ACTIVITY 8-3: IMPCO MIXER TEARDOWN OVERHEAD TRANSPARENCY MASTERS

Liquefied Petroleum Gas Training Program PAGE 8-i Liquefied Petroleum MODULE 8: LPG FUEL SYSTEM OVERVIEW Gas

OBJECTIVES

At the completion of this module, the technician will be able to: • Identify and describe the components of an LPG fuel system. • Describe each component's operation. • Describe each component's interaction with other components and with the whole system. • Select the proper components for a particular conversion. • Operate, dissassemble, troubleshoot, and reassemble components (if applicable). • Be familiar with and discuss the NFPA 58 regulations concerning each component and its use. • Describe LPG closed loop feedback system theory and operation.

Liquefied Petroleum Gas Training Program PAGE 8-ii Liquefied Petroleum MODULE 8: LPG FUEL SYSTEM OVERVIEW Gas

INSTRUCTOR NOTES

INSTRUCTOR MATERIALS/MEDIA NEEDED Overhead projector or LCD panel/projection equipment Master overhead transparencies or Microsoft PowerPoint 4.0 presentation file Mod8.ppt

Note: Slides correspond to text as indicated by icon

VCR with TV or projection unit

Videotape Segment: Manchester Tanks, 10.5 minutes

Note: Videotape segments correspond to text as indicated by icon

Laboratory Activities: Activity 8-1: Data Plate Information Activity 8-2: Regulator Pressure/Volume Relationships Activity 8-3: IMPCO Mixer Teardown

Note: Lab activities correspond to text as indicated by icon

STUDENT MATERIALS/MEDIA NEEDED Module 8: LPG Fuel System Overview

OVERHEAD TRANSPARENCY MASTERS The printouts enclosed with this module are taken from the Microsoft PowerPoint 4.0 presentation file Mod8.ppt . Instructors planning to use overhead projectors should make transparencies from these printouts on a copier (or laser printer designed to safely print to acetate. I

Note: Please review Module 25: Training of Trainers for more hints on instructional needs and strategies.

Liquefied Petroleum Gas Training Program PAGE 8-1 Liquefied Petroleum MODULE 8: LPG FUEL SYSTEM OVERVIEW Gas

FUEL TANKS AND TANK STANDARDS Key Points & Notes Pr opane fuel tanks are constructed of heavy gauge steel or aluminum to withstand the vapor pres s u r es that can be created inside by 8-2 variations in ambient temperatures. A propane fuel tank is actually c o n s i d e red a “pre s s u re vessel” and must conform to safety st a n d a r ds issued by the U.S. Department of Transportation (DOT) or American Society of Mechanical Engineers (ASME). All tanks must be designed, manufactured, tested, and certified in accord-ance with the applicable DOT or ASME codes. Refer to Figure 8-1.

IMPOR TANT NOTE : Under no circumstances shall any container other than an approved DOT or ASME unit, specifically designed for motor vehicle use, be used as a fuel tank in a propane motor vehicle fuel system. Cylinders such as those intended for domestic use or industrial equipment use are not suitable for a legal and safe conversion of over -t h e - r oad vehicles. Generally speaking, only ASME standard tanks should be utilized on these types of vehicles (cars, trucks, vans, buses, etc.).

8-3

Courtesy of N.P.G.A. 8- 1 ASME dataplate for an approved propane fuel tank.

Liquefied Petroleum Gas Training Program PAGE 8-2 Liquefied Petroleum MODULE 8: LPG FUEL SYSTEM OVERVIEW Gas

Key Points & Notes

8-4

Photo © Harris Fogel 8-2 Dataplate

It is beyond the scope of this manual to discuss all the details of the DOT regulations and ASME codes. For further information, you can refer to “Rules for Construction of Unfired Pressure Vessels, Section VIII, Division I, ASME Boiler and Pressure Vessel Code.” For further information on DOT cylinders, refer to the Hazardous Materials Regulations of the U.S. Department of Transportation (Title 49 Code of Federal Regulations Parts 106-180, 49 CFR 106-180). All ASME fuel tanks must have a data plate attached by the manufacturer that lists the following information: 8-5 1. the type of service for which the tank is designed; 2. the name and address of the tank manufacturer or trade name of container; 3. the water capacity (WC) of the tank in pounds or U.S. gallons; 4. the design pres s u r e in psi (externally mounted fuel tanks = 250 psi; trunk mounted tanks = 312.5 psi; and lift truck tanks = 375 psi); 5. the wording means the tank is to be used for propane or butane only; “THIS CONTAINER SHALL NOT CONTAIN A PRODUCT HAVING A VAPOR PRESSURE IN EXCESS OF 215 PSIG AT 100o F (37.8o C).” 6. the tare weight “TW” of the fuel tank fitted for service for applications where the tanks are filled by weight; 7. the outside surface area (SA) in square feet (this information is necessary to determine the proper size of pressure relief valve for the tank. If too small a relief valve is installed, it might not be able to adequately vent excess pressure); 8. the year the tank was manufactured; 8-6 9. the thickness of the shell and heads (ends) of the fuel tank;

Liquefied Petroleum Gas Training Program PAGE 8-3 Liquefied Petroleum MODULE 8: LPG FUEL SYSTEM OVERVIEW Gas

10. The overall length (OL), outside diameter (OD) and height-to -di a m e t e r Key Points & Notes (HD) ratio; 11. the manufacturer’s serial number. Each propane tank has its own number for purposes of identification; and 12. ASME code symbol. NOTE: Tank standards have evolved over 60 years of propane motor fuel use; the standards in effect when the tank is or was installed apply as long as the tank is in service. Manchester Tanks, 10.5 The nameplate is usually stainless steel, permanently attached to minutes the tank in a manner that will resist rust and corrosion and must be visible after the tank is installed in compliance with NFPA 58 Activity 8-1: Data Storage and Handling of Liquefied Petroleum Gases, published by Plate Information the National Fire Protection Association.

GUARD PLATE The valves and hose connections on the fuel tank must be prot e c t e d by a heavy metal guard plate. The guard must be securely attached 8-7 to the tank and should extend far enough around the tank fittings to provide reasonable protection against road hazards and accidental damage while still allowing access to all valves. Further- mo r e, tanks mounted inside the trunk of a vehicle must have all appurtenances vapor sealed in a manner such as to prohibit the possibility of discharging gas into or adjacent to the passenger compartment. This is typically done using a metal housing that en- closes and protects the valves and apertures sealing them from the passenger compartment. This housing is known as a “seal shell.”

SELECTING THE RIGHT DESIGN AND SIZE OF FUEL TANK One of the most important decisions the technician must make while planning the conversion to propane is the sizing of the fuel 8-8 tank. Correctly sizing the tank to the application involves several considerations: 1. maximum required driving range (See Tables 8-1A, 8-1B); 2. fuel availability; 3. type of conversion; and 4. physical limitations. Fuel tanks can range in size from a few gallons up to a maximum total capacity of 300 gallons WC. NFPA 58 provides that the 8-9 maximum allowable fuel tank size for vehicles operating on highways, other than passenger-carrying vehicles, shall not exceed 300 gallons WC. The maximum aggregate tank capacity for a passenger-carrying vehicle is 200 gallons WC. The reason for setting limits on tank size is to minimize the fire hazard in case of an accident. Fuel tank sizes commonly used for passenger cars range from 20 gallons up to 40 gallons WC. The tank or tanks are usually installed in the trunk. For light trucks, vans and medium-to-heavy duty trucks, tanks ranging in size from 25 to 115 gallons are frequently used.

Liquefied Petroleum Gas Training Program PAGE 8-4 Liquefied Petroleum MODULE 8: LPG FUEL SYSTEM OVERVIEW Gas

Propane tank capacities are rated relative to how much water the Key Points & Notes tank will hold when completely filled with water. In practice, however, the fuel tank is never filled to capacity. It is filled to only 80 percent of its water capacity (WC) to allow room for thermal expansion. Unlike water, propane expands considerably as the temperature rises. When the tank is filled on a cool morning to 80 percent capacity, the fuel could expand to 90 percent of the tank’s capacity by the middle of the afternoon on a hot day. If no room were provided for thermal expansion, pressure inside the tank would quickly rise. If the pressure becomes excessive, the pressure relief valve would release the pressure, creating a potential hazard where the propane is vented as well as fuel loss. For this reason, the 80 percent filling rule should always be observed. Virtually all tanks manufactured today are equipped with 80 percent automatic stop fill valves. Even so, it is still necessary to use the fixed liquid level gauge or bleed valve style propane vehicle fuel tank. However, efforts are under way to eliminate the bleed valve and prevent hydrocarbons from escaping into the atmosphere. Propane tanks are shaped like cylinders. Diameters of propane engine fuel tanks typically range from 12” to 24”, with lengths 8-10 ranging from about 30” to 80”. Double tanks (also called “manifold” tanks), consisting of two or more cylinders connected with pipe manifolds and mounted side by side, are sometimes used when space is limited, such as in the trunk of a passenger car. There are also tanks shaped like a drum to fit into the spare tire well of passenger cars. Other than provisions in NFPA 58 mentioned earlier regarding tank capacity, there are no restrictions on the dimensions of a propane fuel tank. The shape and capacity of the fuel tank should be chosen to fit the application. Tank weight and design are a factor that should be considered when converting a vehicle to propane. The 4-to-1 safety factor included in the design of the tank means a typical steel propane fuel tank will be relatively heavy compared to a thin metal or plastic gasoline tank. The added weight of the heavy tank is offset by the lighter weight of propane – about 2 pounds less per gallon than gasoline. For tanks of equivalent size, a filled propane tank may weigh about the same as a full gasoline tank. For example, a 25-gallon propane tank might weigh around 100 pounds empty and approximately 180 pounds when filled to 80 p e rcent capacity with propane. A 25-gallon gas tank, by comparison, might weigh only 30 pounds empty but would weigh around 180 pounds when full of gasoline. Take care to to choose a tank suitable for the application. FUEL TANK INSTAL L A TION IN ENCLOSED COMPARTMENTS A tank that is mounted in an enclosed compartment such as the trunk or passenger compartment must have a working pres s u r e of at 8-11 least 312.5 psi and have a gas tight vapor shield to seal the tank and/ or fittings from the passenger compartment. Refer to Figure 8-3.

Liquefied Petroleum Gas Training Program PAGE 8-5 Liquefied Petroleum MODULE 8: LPG FUEL SYSTEM OVERVIEW Gas

Key Points & Notes

8-12

Photo © Harris Fogel

8-3 Trunk-mounted tank fittings, seal shell open NFPA 58, 8-2.7 lists the following options: • The compartment containing the tank fittings must be sealed from the passenger compartment, using approved materials. 8-13 • The tank(s) must be designed so the valves and fittings are routed outside of the passenger compartment. • The most common tank used currently is one that is manufactured with a vapor seal cover or fitted with a vapor seal that meets NFPA 58 provisions. In all of the above options, containers must be fitted so that no gas f rom fueling or normal operations enters the passenger compartment or trunk. This may be accomplished by installing fixed remote fueling connections. Any spark producing equipment, such as radio equipment, must also be isolated from tank(s), valves, and fittings. In addition, the enclosed compartment must be vented outside the vehicle at the lowest point. PROPANE VALVES The valves used in propane fuel tanks and assemblies are usually made of brass and adhere to strict industry standards. These 8-14 valves are listed for propane service and sometimes for the specific application for which they are being used. Refer to Figure 8-4.

PRESSURE RELIEF VALVE Every propane fuel tank must be equipped with an internal spring type pressure relief valve that will open automatically to vent vapor 8-16 if internal tank pressure exceeds the relief valve start-to-discharge pressure setting. Refer to Figure 8-5. The relief valve is designed so the spring and valve seat portion are inside the tank, which helps to protect the tank and reduce the chance of fuel loss in case the outer part of the valve is sheared off in an accident. Relief valves must be approved or listed by a nationally recognized testing laboratory, generally U.L. The opening on the fuel tank

Liquefied Petroleum Gas Training Program PAGE 8-6 Liquefied Petroleum MODULE 8: LPG FUEL SYSTEM OVERVIEW Gas

LIQUID LEVEL GAUGE PRESSURE Key Points & Notes INDICATES WHEN TANK IS RELIEF FILL FUEL SUPPLY AND MANUAL FILLED TO 80% CAPACITY VALVE VALVE SHUT OFF VALVE

8-15

FUEL GAUGE OR SENDER UNIT

PROTECTIVE GUARD PLATE

DATAPLATE Photo © Harris Fogel 8- 4 A typical propane fuel tank configuration. where the relief valve must be installed is labeled “RELIEF.” The relief valve tank port is positioned above the liquid in the vapor space to ensure that the valve will discharge vapor and is designed to relieve a given volume of vapor at a set pressure. The pressure relief valve must be labeled to show 8-17 the rated pre s s u re at which it will open, the rate 8-18 of discharge in cubic feet per minute of air (CFM), the manufacturer’s name and catalog part number, and date of manufacture. Check manufacture r s ’ tables for proper sizing. It must also be rated for Courtesy of Rego the pressure required for its application. 8- 5 Pre s s u r e relief valve.

FILL VALVE The fill valve is the valve through which the fuel tank is refueled. Refer to Figure 8-6. The valve must be a double back-check design. 8-19 If the upper portion of the valve is sheared off, the bottom portion of the valve retaining the back-check will remain inside the tank and seal the opening to minimize any loss of fuel. There are two basic types of fill systems – direct and remote. A direct fill valve is used on externally mounted fuel tanks where the tank is easily accessible and can be refueled directly. Direct filling requires a 1-3/4” Acme thread with a dust cap. The portion

Liquefied Petroleum Gas Training Program PAGE 8-7 Liquefied Petroleum MODULE 8: LPG FUEL SYSTEM OVERVIEW Gas

of the valve that threads Key Points & Notes into the tank is 3/4 NPT or 1-1/4” NPT. 8-20 Remote fill connections are req u i r ed on fuel tanks that ar e mounted inside vehicles or underneath where access to the fill valve is Courtesy of Rego limited. NFPA 58 req u i re s 8- 6 Fill valve. remote filling systems for all fuel tanks that are mounted inside a vehicle trunk or exposed to the passenger compartment to prevent discharging fuel inside the passenger or luggage compartment during refueling. The remote fill adaptor must include a double back check-valve. The threaded connection will be a 1-3/4” Acme thread with a dust cap. NF P A 58 provides that tanks manufactured after June 30, 1985 be equipped with an automatic stop-fill valve. There are several designs available, utilizing either a float movement or pres s u r e diffe re n t i a l design. Consult the tank manufacturer for more informa t i o n . The tank installer is responsible for ensuring that this stop fill valve is installed.

80 PERCENT FIXED LIQUID LEVEL GAUGE The fixed level gauging device (bleed valve, “spit” valve, or outage valve) is used to determine when the fuel tank has reached 80 8-21 percent of its WC during refueling. Refer to Figure 8-7. The valve has a #54 drill size orifice through which a white cloud spurts when the liquid level in the tank reaches the 80 percent level. The white cloud is not propane at all; it is condensed water vapor resulting from the chilling effect of the liquid propane flash-vaporizing across the orifice.

8-22

Photo © Harris Fogel 8- 7 The bleeder valve signals when the tank is filled to 80% capacity. Tan k s built after June 30, 1983 use an automatic device to prevent over filling.

Liquefied Petroleum Gas Training Program PAGE 8-8 Liquefied Petroleum MODULE 8: LPG FUEL SYSTEM OVERVIEW Gas

Where remote fill is required, a manual shutoff valve should be Key Points & Notes installed in the liquid level gauge opening and must be protected with a #54 drill orifice. This will allow the bleeder valve hose to be disconnected without having to empty the fuel tank. The fixed liquid level gauge must be used when filling the tank even if the tank is equipped with an automatic stop-fill valve.

PROPANE LIQUID 8-23 SERVICE/SHUTOFF VALVE

The service valve is installed 8-24 di r ectly into the motor fuel tank to provide for shut off of liquid fuel flow to the engine. The valve must be listed or a p p roved and otherwise comply with provisions of NF P A 58. The valve must also include an intern a l excess flow check valve. In Courtesy of Rego the event the fuel line is damaged or ruptured, any 8- 8 Manual shutoff excess flow valve. sudden surge of fuel throu g h the line in excess of its rating causes the excess flow valve to close, restricting the flow of fuel from the tank and minimizing the hazard that could be created by an open fuel line. These check valves are generally rated from 1.7 to 2.4 gallons per minute (gpm). If the excess flow valve is checked shut, fuel flow will be reduced to a minimum and will not allow the vehicle to operate until the valve is reset. To reset, turn the fuel supply valve completely off and wait for about 10 seconds, then reopen slowly. Refer to Figure 8-8. Like the filler and relief valves, the excess flow mechanism is designed to minimize fuel loss in the event of an accident. If the

8-26

Photo © Harris Fogel 8- 9 Liquid and vapor valves.

Liquefied Petroleum Gas Training Program PAGE 8-9 Liquefied Petroleum MODULE 8: LPG FUEL SYSTEM OVERVIEW Gas outer portion of the valve is broken off, the inner part remains intact Key Points & Notes inside the fuel tank to restrict fuel loss. Like all the other valves and pressure fittings in the fuel system, it must comply with listed standards. VAPOR SERVICE VALVE Although not used on most automotive applications, some propane fuel tanks are equipped with a connection for installing a vapor 8-25 service valve. Refer to Figure 8-9. The fuel supply tube inside the tank is positioned so only propane vapor will pass through this valve. Because most engine fuel systems use liquid propane, this aperture is usually plugged. There are some small engine applications where vapor service is adequate. When required, the vapor service valve must meet the same requirements as the liquid withdrawal valve, including an internal excess flow valve.

FUEL GAUGE The fuel gauge uses a float to determine the liquid volume inside the tank. As the liquid level inside the tank changes, the float moves 8-27 accordingly.

8-28

Photo © Harris Fogel 8- 1 0 Tank float.

The fuel gauge consists of a float arm attached to a stem and is installed in a flange on the tank. Refer to Figure 8-10. The float arm moves a magnet that is geared to tu r n a shaft and a dial assembly, 8-29 thus indicating the fuel level in the tank. Fuel tanks can be fitted with a direct reading magnetic dial or with a sending unit that can be connected to an auxiliary dash-mounted fuel gauge, known as a rec e i v e r , or an Original Equipment Manu- fa c t u r er (OEM) fuel gauge. Refer to Figure 8-11. If the OEM fuel Photo © Harris Fogel gauge is used, be sure that the 8- 1 1 Fuel gauge.

Liquefied Petroleum Gas Training Program PAGE 8-10 Liquefied Petroleum MODULE 8: LPG FUEL SYSTEM OVERVIEW Gas sending unit has the same ohm value as the gauge. The dial/ Key Points & Notes sending unit is a separate, externally mounted component to the fuel gauge and may be changed without removing the fuel gauge assembly. The fuel gauge should not be used for tank ref u e l i n g . Only the bleeder valve and automatic shutoff device should be used to determine when the tank is filled to 80 percent capacity. FUEL LINES, LOCKS AND FILTERS

FUEL LINES The fuel line supplies propane at tank pressure to the under-hood carburetion components. The fuel line must comply with provisions 8-30 of NFPA 58. Flexible stainless steel wire braided hose is the most common type used. Wrought iron, steel, brass or copper pipe, and steel or brass seamless tubing can also be used if they conform to the provisions of NFPA 58. Hose is generally preferred in the industry because it is easily installed, long lasting, and has an excellent safety record. N F PA 58, Section 8-2.5 Piping, Hose, and Fittings, covers requirements of LPG fuel lines, which generally states lines and fittings should be tested and able to withstand working pressures of 350 psi with a safety factor of 5:1, or burst pressure of 1750 psi. Section 8-2.8 Pipe and Hose Installation covers general requirements of fuel line installation, which seek to reduce line damage and loose connections.

PIPE AND TUBING NF P A 58 contains specific provisions for the type of pipe and tubing (including hose) that may be used for vehicle applications. If pipe or 8-32 tubing is req u i r ed, it must comply with NFPA 58. All fittings used for liquid propane on a vehicle should be only heavy walled brass with a 45o Society of Automotive Engineers (SAE) flare. Thirty-seven de g r ee JIC flares, usually used for hydraulic hose, must no t be used. The system manufacturer should provide the tubing, fittings, and fitting sealant with the system. Pipe may be made of wrought iron,

8-31

Tank 1 Tank 2

To Engine Courtesy of Sherwood 8-12 Two tank check valve (cutaway).

Liquefied Petroleum Gas Training Program PAGE 8-11 Liquefied Petroleum MODULE 8: LPG FUEL SYSTEM OVERVIEW Gas steel, brass, copper, or polyethylene, and comply with Section 2-4.2 Key Points & Notes requirements. Tubing may be made of steel, brass, copper, or polyethylene, and comply with Section 2-4.3 requirements. Exact specifics and techniques for working with pipe and tubing will not be covered in detail in this manual. However, for systems that involve pipe and tubing, bending will probably be necessary. Special fuel line bending tools and tube bending guides will help the installer to manipulate the lines. Please refer to these manufacturer’s instructions. Hose is the most commonly used and easiest to work with fuel line. Hose should comply with the regulations in Section 2-4.6. Look for 8-33 hose that is gasoline and oil resistant with a non-leaching thermoplastic liner, reinforced with stainless steel wire braid, and a rubber or cloth weave gasoline and oil resistant outer sheath. Each installed section of the hose must be marked “LP GAS, P R O PANE, 350 PSI WORKING PRESSURE, 1750 PSI BURST PRESSURE”, and include the manufacturer’s name, and be UL listed for LPG use every 18 inches. Do not use push-on type hose for fuel lines.

HOSE If flexible hose is used for the fuel line, it must be stainless steel wire braid reinforced and listed or approved for use with LP-gas or 8-36 propane. The hose must have a minimum working pressure of 350 psi, have a rated burst strength of at least 1750 psi, and be marked with this working pressure and “LPG” every 18 inches of installed length. High-pressure fittings are used on flexible hose to make the connections. The fittings must conform to the provisions of NFPA 58, and are usually two-piece reusable, or mandrel type fittings. These hose-end fittings should be only SAE 45o flare. Refer to

8-34

Photo © Harris Fogel 8- 1 3 Flexible hose and fittings.

Liquefied Petroleum Gas Training Program PAGE 8-12 Liquefied Petroleum MODULE 8: LPG FUEL SYSTEM OVERVIEW Gas

Figure 8-14. Push-on type fittings must Key Points & Notes never be used on propane/LP-gas liquid fuel lines because they are not designed to withstand the comparatively high 8-35 p re s s u res that may be encountere d . Crimped collet type fittings may be used if approved or listed for propane or propane service.

FITTINGS Fittings are used at the ends of the hose to make connections to the components. 8-37 Fittings should be high pressure, brass, steel, copper, malleable iron, or ductile iron, and conform to Section 8-2.5. They Photo © Harris Fogel o should have 45 SAE inverted flares; do 8- 1 4 45o SAE flare elbow. not use 37o JIC flares. Usually the models are two-piece reusable, mandrel-type, or approved crimped collet-type and include straight, 45o, and 90o elbows. Common bulkhead fitting configurations include straight-through, three- way, and four-way outlets. Do not use push-on-type fittings.

HYDROSTATIC RELIEF VALVE A hydrostatic relief valve with a start-to-discharge pressure between 400 to 500 psi must be installed in the liquid fuel line between any 8-38 two positive shut-off valves. Refer to Figure 8-15. In a motor fuel installation, this relief valve is usually located in a bulkhead assembly. The valve’s purpose is to vent excessive pressure that may occur if the two shut-off valves are closed, trapping liquid propane in the piping. A relief valve discharge should not impinge against any vehicle and must be directed away from a source of ignition. The discharge outlet must be covered with a protective cap.

8-39

Photo © Harris Fogel 8- 1 5 Hydrostatic relief valve/bulkhead assembly (w/o dust cap).

Liquefied Petroleum Gas Training Program PAGE 8-13 Liquefied Petroleum MODULE 8: LPG FUEL SYSTEM OVERVIEW Gas

HYDROSTATIC Key Points & Notes RELIEF VALVE TRUNK FLOOR, BED OR FRAME 8-41

BULKHEAD FITTING TO TANK

NUT

WASHER PROPANE LINE

TO CONVERTER Courtesy of N.P.G.A. 8-16 Hy d r ostatic relief valve threaded into bulkhead fitting. BULKHEAD FITTINGS A bulkhead fitting is a fuel line connection that is used when the fuel line must be routed through sheet metal body panels on a vehicle. 8-40 Refer to Figure 8-16. Bulkhead fittings are manufactured in configurations that include straight-through, three-way, and four- way outlets with 1/4” NPT or 3/8” SAE flare thread connections. Often, these fittings are made in conjunction with a filter system and may incorporate a point for the installation of a hydrostatic relief valve and a check valve for multiple tank installations.

FUEL LOCK AND AUTOMATIC SHUT-OFF VALVE The propane fuel lock, or “lock-off” valve as it is commonly called, is installed to allow the flow of fuel to the engine only when the fuel 8-42 is required. Refer to Figure 8-17. There are two common types of

8-43

Courtesy of IMPCO 8-17 Fuel lock and automatic shutoff valve.

Liquefied Petroleum Gas Training Program PAGE 8-14 Liquefied Petroleum MODULE 8: LPG FUEL SYSTEM OVERVIEW Gas lock-offs available – the vacuum type and the electrical solenoid Key Points & Notes type. Some of these valves even incorporate a filter. NFPA 58 requires that this valve be a means of positive shut-off, whether the engine is intentionally or accidentally stopped even if the ignition system is still energized. Although vacuum lock-offs are capable of this action, electrical models are not and must be installed with either a vacuum or oil pressure switch in the circuit. An engine that is cranking or running produces both manifold vacuum and oil pressure. When the safety switch senses the presence of vacuum or oil pressure, it opens the lock-off and allows fuel to pass from the tank to the vaporizer. If vacuum or oil pressure drops below the threshold level, the fuel lock shuts off the fuel.

FUEL FILTERS An in-line filter should be installed in the system. 8-44 Refer to Figure 8-18. Most of these typically have 8-45 replaceable filter elements. Some assemblies must be removed from the system to replace the filter. The tee- type filter does not req u i r e Courtesy of Squibb Taylor removal of the filter body 8-18 Fuel filter. f rom the line to change elements. In operation, the liquid propane passes from the outside ar ea of the filter element to the inside. This provides a large effe c t i v e filtering area and eliminates the possibility of the element being unseated because of pres s u r e buildup or pulsations. The element traps contamination, allowing the cleaned gas to pass through the system. Various materials are used in the filter elements including woven fibers, sintered brass, and gauze-like pads. Under no ci r cumstances should any filter not listed for use with propane be installed or substituted in the system. CONVERTER VAPORIZER-REGULATOR The converter, also called the vaporizer-regulator, is located in the fuel system between the fuel lock and the air-fuel mixer. Refer to 8-46 Figure 8-19 and 8-21. Its function is to convert tank-pressure liquid propane into low-pressure propane vapor before it enters the air-fuel mixer. The unit is commonly called a converter because it converts high-pressure liquid to low-pressure vapor. This is usually a single component; however, in some applications a separate vaporizer and regulator are used.

LIQUID TO VAPOR Changing propane from a liquid into a vapor is accomplished by metering fuel into an expansion chamber inside the converter. Refer to Figure 8-20. As fuel pressure drops, the fuel expands and the volume increases. This expansion causes a refrigeration action. To prevent the converter from “freezing up,” a source of heat must 8-47 be introduced to the converter to absorb this refrigeration. In most

Liquefied Petroleum Gas Training Program PAGE 8-15 Liquefied Petroleum MODULE 8: LPG FUEL SYSTEM OVERVIEW Gas

11 8 9 10 12 13 Key Points & Notes

8-48

1 2 3 4 5 6 7

1. Fuel (liquid) inlet 8. Fuel inlet to secondary 2. High-pres s u r e (primary) chamber regulator valve (dotted line 9. Secondary valve – lever, pin, shows open position) seat & spring (dotted line 3. Primary valve spring shows open) 4. Vaporizing chamber 10. Secondary diaphragm 5. Primary diaphragm 11. Fuel (vapor) outlet 6. Fuel passage to primary 12. Primer button diaphragm chamber 13. Atmospheric vent or orificed 7. Water (Coolant) passage el b o w 8-19 OHG X-1 Converter Vap o r i z o r -Regulator cutaway.

UNDERSIDE OF BODY ASSEMBLY (MID-SECTION) 8-49 SHOWING HIGH-PRESSURE (PRIMARY) REGULATOR VALVE

Water (coolant) passage Vaporizing chamber

Peter Aschwanden 8-20 Liquid-to-vapor high-pres s u r e valve and vaporizing chamber.

Liquefied Petroleum Gas Training Program PAGE 8-16 Liquefied Petroleum MODULE 8: LPG FUEL SYSTEM OVERVIEW Gas

Orificed elbow for fuel control valve - feedback systems Primer button Cover screws Secondary cover assembly

Secondary diaphragm

Secondary valve - lever, seat, pin & spring

Primary diaphragm cover

Primary regulator spring Primary diaphragm

Body assembly (mid-section)

Pressure test plug

Fuel (vapor) outlet

Primary valve pin Vaporizing chamber gasket

Fuel (liquid) inlet

Vaporizing chamber cover

Cover screws

Primary valve, spring, O-ring and plug

Peter Aschwanden

8-21 OHG X-1 Converter Vap o r i z o r- R e g u l a t o r , exploded view. 8-50

Liquefied Petroleum Gas Training Program PAGE 8-17 Liquefied Petroleum MODULE 8: LPG FUEL SYSTEM OVERVIEW Gas automotive applications, heat is provided by circulating engine Key Points & Notes coolant around the expansion chamber inside the converter. Ribs or fins cast into the expansion chamber cavity and the surrounding water jackets create a large surface area for efficient heat transfer between the fuel and hot water. At no time does the fuel make direct contact with the coolant. Converter efficiency depends on the ability of the system to absorb this refrigeration at a rate capable of supplying the required fuel load. Fuel entering the converter is controlled by the high-pressure valve. The valve is controlled by a diaphragm that reacts to vapor pressure inside the expansion chamber. As fuel vaporizes, or expands, its Activity 8-2: Regulator volume increases. As this volume fills the expansion chamber, Pressure/Volume pressure is applied to a diaphragm closing the high pressure valve. Relationships

PRIMERS Some automotive converters are equipped with a starting aid known as a primer. The primer is activated by an electric solenoid, control 8-51 cable or valve, or push button. When activated, the primer supplies a small amount of fuel to the mixer and engine by either opening a control valve or opening the secondary diaphragm and valve, allowing fuel vapor to fill the vapor hose to the air-fuel mixer. When installed properly, the primer should be activated only long enough to supply fuel for starting. Primers should only be installed so that they are activated by the starter circuit. However, most systems do not require a primer unless the engine is very weak. VAPOR HOSE The converter is connected to the air-fuel mixer with a hose (usually between 3/4” and 1-1/4”) or, in some applications, it is attached 8-52 di r ectly to the air-fuel mixer. Refer to Figure 8-22. Always follow the ma n u f a c t u r er’s recommendations on hose sizing and application. It is very important that the hose used for the vapor connection be

8-53

Photo © Harris Fogel 8-22 Vapor hose connected to mixer

Liquefied Petroleum Gas Training Program PAGE 8-18 Liquefied Petroleum MODULE 8: LPG FUEL SYSTEM OVERVIEW Gas resistant to the action of propane and listed for this purpose. Do no t Key Points & Notes use water hose or other such unlisted products for liquid or vapor pro p a n e .

AIR FUEL MIXERS

FUEL METERING THEORY The carburetor in a propane fuel system is usually ref e r r ed to as the ai r -fuel mixer because its job is to mix air and fuel together in the 8-54 co r r ect proportions. The basic concept behind fuel metering is to pr ovide more fuel as the amount of air entering the engine increa s e s .

8-56

IDLE HALF-THROTTLE FULL THROTTLE 8-23 Air valve mixer showing air valve positions under diffe r ent loads.

As the throttle opens, allowing more air into the engine, the mixer must supply more fuel to maintain the correct air-fuel ratio. Ideal combustion of air and fuel is called stoichiometry. Ten percent to the rich side of stoichiometry results in best engine perfo r mance; ten pe r cent to the lean side of stoichiometry provides best economy. Th e re f o r e, a compromise must be reached to maintain good emissions, perfo r mance, and economy over a wide range of operating loads and conditions. Equipment manufacturers have taken diffe re n t ap p r oaches to building a device that can satisfy the changing air-f u e l req u i r ements of the engine and maintain the correct air-fuel ratio to satisfy the PCM and operate the catalytic converter. The two basic types of air-fuel mixers in use today are the air-valve mixer and the venturi principle mixer. 8-55 AIR-VALVE MIXERS In all spark-ignition 8-57 engines, the thro t t l e co n t r ols the weight of air flowing into the engine. The air valve mixer mixes fuel and air upstream of the throttle; the mixing takes place when the fuel meets the air stre a m . Courtesy of IMPCO Refer to Figure 8-23. The 8-24 Air valve.

Liquefied Petroleum Gas Training Program PAGE 8-19 Liquefied Petroleum MODULE 8: LPG FUEL SYSTEM OVERVIEW Gas ai r -valve assembly also meters fuel using a spring-loaded diaphragm Key Points & Notes or piston that moves in relation to the weight of air flowing into the engine. Refer to Figure 8-24. Spring pres s u r e keeps this valve closed when the engine is not running. Venturi vacuum passes through small transfer passages in the air- valve to reduce the pressure in the chamber over the diaphragm. Atmospheric pre s s u re of the air passing across the transfer passages creates a pressure differential or pressure drop on the top side of the diaphragm (or piston), lifting the diaphragm and gas metering valves. This system meters fuel in direct and constant proportion to the air flow; the greater the air flow (weight of the air), the higher the rise of the air valve. The air valve compensates for changes in altitude. Gas and air Activity 8-3: IMPCO decrease in density as altitude increases; the air-valve responds to Mixer Teardown the lighter, less-dense, air and meters the fuel accordingly.

8-58

Peter Aschwanden 8-25 OH G X-450, exploded view.

Liquefied Petroleum Gas Training Program PAGE 8-20 Liquefied Petroleum MODULE 8: LPG FUEL SYSTEM OVERVIEW Gas

VENTURI PRINCIPLE MIXERS Key Points & Notes Another approach to air-fuel metering is the use of the “venturi principle.” When air passes through a narrow restriction, called the 8-59 venturi, it speeds up and creates a drop in pres s u r e. Venturi mixers ar e mounted either above or below the throttle. The venturi shape of these mixers causes the air flow into the engine to speed up, causing a low-pres s u r e zone in the mixer. Small holes or slots below the venturi allow fuel to pass into the air stream and mix with the air. As the air flow increases, pres s u r e diffe r ential increases and fuel supply increases. At idle, when air flow is low, the fuel mixture is usually controlled with a separate idle circui, which sends fuel from the converter to the carburetor under pres s u r e. This circuit closes after air flow increases beyond its control. This system is very common on small, special-purpose engines because it is easy to install. A venturi mixer is designed to meter fuel well at fixed engine speed. Because it has no moving parts, the venturi mixer is low maintenance. FUEL SWITCHING AND MONITORING COMPONENTS Many systems include electronics modification features. These features allow for closed feedback systems for improved emissions 8-60 performance and power, timing changes, and false code protection. Because most new vehicles feature digital electronic systems, the tolerance of the electrical signals must be tighter. The majority of electrical problems that will be encountered will be due to poor connections which increase resistance and drop the voltage enough to alter the signal. Refer to Figure 8-26.

8-61 6 3 VIOLET/WHITE – MODE SELECT OUTPUT

PROPANE BLACK – FUEL PUMP POWER OUTPUT

GASOLINE TANK SENDING UNIT

OFF 5 2 BLUE – FUEL PUMP POWER INPUT

RED – CONTROLLER POWER OUTPUT

OEM FUEL GAUGE GASOLINE LPG TANK SENDING UNIT

4 1 BROWN – LOCK-OFF POWER UNIT

Courtesy of Algas Carburetion 8- 2 6 Diagram of fuel selector switch installation.

TIMING ADAPTATION COMPONENTS Because of the slower burning speed of propane, the spark timing may need to be advanced so spark occurs earlier than set for best 8-62 ignition on gasoline. This is usually accomplished by wiring in a timing advance processor, also called a recurve module, dual curve, or timing optimizer. Refer to Figure 8-28. •Timing Delay Method – requires that the distributor be physically set 15o advanced of factory base timing. When operating on 8-64

Liquefied Petroleum Gas Training Program PAGE 8-21 Liquefied Petroleum MODULE 8: LPG FUEL SYSTEM OVERVIEW Gas

gasoline, the timing recurve device electronically retards the Key Points & Notes timing 15o, so the timing is returned (retarded) to operate at factory specifications in gasoline mode. When in LPG mode, the timing may be electronically adjusted to 0 to 15o, depending on engine RPM. For example, if the distributor is set 15o advanced, and the LPG module retards timing 6o, the result would be 15o–6o = 9o advance. •Timing Advance Method – advances ignition timing on propane gas by sensing two gasoline primary ignition signals on two cylinder 8-65 spark events. The timing advance for the third event is calculated by the previous two. It takes only three milliseconds at 2000 RPM for the timing advance device to calculate and advance the timing. The OEM gasoline ignition input signal is always monitored by the timing advance device. The output is modified to advance and trigger ignition timing to suit the burning characteristics of propane. Refer to Figure 8-27. •Timing Optimization Method – provides timing adjustments as the engine is loaded. This method works from a MAP (Manifold 8-67 Absolute Pressure) sensor. The MAP sensor converts engine vacuum to 0-5 volts, depending on engine load. Another strategy for timing optimization is to adjust ignition timing by reading TPS (Throttle Position Sensor) voltage. The processor calculates engine load by sensing throttle position which correlates to engine load. The TPS strategy also uses RPM to keep timing at factory- base timing until the engine speed is above 500 RPM, thus keeping the engine from backfiring during start up.

50o 8-66

40o LPG Curve

30o

Gasoline Curve 20o

10o

Courtesy of Autotronic Controls TDC 1000 2000 3000 4000 5000 6000 7000 Engine Speed (RPM) 8-27 Ignition Timing Curve, LPG and Gasoline

Liquefied Petroleum Gas Training Program PAGE 8-22 Liquefied Petroleum MODULE 8: LPG FUEL SYSTEM OVERVIEW Gas

NOTE: Many new engines have turbulent combustion chambers Key Points & Notes that burn the combustible charge rapidly. While modified timing advance may improve propane performance on some engines, it may not be necessary on engines with fast burning combustion chambers. Advanced timing may increase emissions and decrease performance. LPG CLOSED LOOP FEEDBACK SYSTEMS LPG fuel mixture feedback control systems work similarly to gasoline computer-controlled fuel injection and feedback systems. 8-68 The computer uses data from a series of engine sensors to control engine operating functions. The input signals are processed, and the correct computation for each operating mode is relayed to the various engine controls. NOTE: It is illegal to convert a vehicle, originally equipped with a feedback system, without using an approved equivalent LPG feedback system. This federal law holds true in every state, unless otherwise specified by regulation, regardless of whether or not it has an emissions testing program. The supplemental LPG feedback systems are engineered to use the existing OEM computer and sensors without modification. The computer itself is a logic switching device that may retain some memory. This capability enables it to act rather than just react and operate in two basic methods of operation – open loop and closed loop.

COLD START Note: The following information describes a propane closed loop feedback system. 8-69

The system is designed to operate in open loop until the O2 sensor warms up. The computer then watches the O2 sensor cross counts. And after a certain number of counts during a given period of time, the system goes into closed loop. During cold start, fresh air from the air injection pump may be directed into the engine exhaust manifold. The fresh air provides additional oxygen in the exhaust manifold to prompt continued burnoff of excess fuel and further reduction in HC and CO

5Volts 8-63

0Volts

Sample Sample Timing advanced Event #1 Event #2 (device output) as calculated from samples 1 and 2 Ignition is triggered on the falling edge of the square wave Fred Moreno 8-28 Digital sampling to advance timing on LPG

Liquefied Petroleum Gas Training Program PAGE 8-23 Liquefied Petroleum MODULE 8: LPG FUEL SYSTEM OVERVIEW Gas

To mixer valve vacuum port 6”–8” W.C. Mount solenoid here Install 3/16” Throttle position sensor vacuum line Back-check valve with orifice Fuel control valve TPS signal Convertor

TPS ground

Gray wire Female Violet wire fastons Blue wire control signal

Dk. blue wire +12v Orange on alternate fuels wire +12 to solenoid

To factory computer For monitoring Cut 1 loop for 6 cylinder vehicles actual O2 signal Cut 2 loops for 4 cylinder vehicles Green wire Oxygen Courtesy Autotronic Controls sensor 8-29 LPG Feedback Processor. 8-71 emissions. When the catalytic converter reaches operating temperature, the air pump vents to atmosphere. On the system shown in Figure 8-29, the computer meters a richer fuel mixture to the engine during the cold start. Once the system 8-70 closes loop, the fuel control valve dithers (rapidly switches) control pressure on the regulator. This adjusts the air-fuel mixture by computer command. A fuel injected system uses fuel flow control solenoids and trim injectors to control the air-fuel ratio. During cold start, fueling is open loop (slightly rich). Once the computer determines the engine is warm, it puts the system into closed loop.

STABILIZED ENGINE CLOSED LOOP OPERATION In the closed loop, the computer maintains active control over the air-fuel ratio by processing information from various sensors. The 8-72 O2 sensor, the MAP sensor, the TPS sensor, and others are used to calculate the correct air-fuel ratio. The closed loop mode has a wider angle of control allowing it to optimize the engine’s performance under all load and operating conditions. This system

Liquefied Petroleum Gas Training Program PAGE 8-24 Liquefied Petroleum MODULE 8: LPG FUEL SYSTEM OVERVIEW Gas e ffectively controls power, perf o rmance, emissions, and fuel Key Points & Notes economy.

The O2 sensor, which is located in the exhaust system ahead of the catalytic converter, is the reference control for stabilized engine closed loop operation. When the mixture is lean (0.0–0.5 volts or 0–500 millivolts), the propane computer responds by increasing the amount of fuel supplied to the engine. If the O2 signal is rich (0.5–1.0 volts or 500–1000 millivolts), the computer supplies less fuel to the engine. Many systems still req u i r e a manual adjustment of the idle and load mi x t u r e limits. To eliminate tampering, systems are now designed to 8-73 be non-adjustable. Some computers also have adaptive learn capability: the ability to rec o r d common drivability conditions and calculate the correct fueling responses based on learned sensor inputs. If the air-fuel ratio goes out of range – too rich or too lean – the pr opane fuel control system loses control. In this case, the system defaults to the OEM computer and an OEM diagnostic trouble code is st o r ed; the MIL (Malfunction Indicator Light) may light. With the engine at operating temperature and the computer in closed loop, feedback systems can assure extremely accurate fuel delivery and rapid response time.

ELECTRONIC CONVERSION SUPPORT MODULES Gasoline (OEM) computer systems are calibrated to control air-f u e l mi x t u r es ideal for gasoline. When running on propane, the OEM 8-74 computer may generate trouble codes because the two fuels have di ff e r ent combustion characteristics. The OEM computer looks for signals typical to gasoline. If the inputs are out of range, trou b l e codes, poor driveability or both may result. These conditions are avoided using supplemental electronic interface modules. These modules may be req u i r ed on certain applications and only if permi t t e d by law – never as a substitute for a closed loop feedback system. NOTE: Do not install any device that modifies OEM computer systems unless the support is legally approved. It is essential that the propane computer does not interfere with the operation of the gasoline fuel and emissions system. The electronic modules in the propane system must interface but not interfere with OEM computer operation. Support modules and feedback control modules are commonly combined into integrated units. Refer to Figure 8-30

Knock Sensor Signal Interface This module monitors the knock sensor circuit and then responds with a sensor signal. Some of these systems periodically send a 8-76 simulated knock frequency to the OEM computer telling it that the sensor works. Others send a simulated signal only when an ignition condition that should generate a knock is produced. This prevents a false knock sensor malfunction code.

Liquefied Petroleum Gas Training Program PAGE 8-25 Liquefied Petroleum MODULE 8: LPG FUEL SYSTEM OVERVIEW Gas

EGR Interface Key Points & Notes This module monitors OEM computer signals related to exhaust gas recirculation and responds with the correct sensor signals. Some of 8-77 the support systems will send a false lean O2 sensor signal when the EGR opens. Other systems drive the fuel mixtures lean when the EGR is open. This prevents a false EGR malfunction code while allowing true failure conditions to be recognized.

EGO/HEGO Sensor Interface

This module supplies a simulated O2 feedback signal to the OEM computer. Some support systems always send a false signal to the 8-78 OEM computer when on propane. Other systems will cease to send the false signal to the OEM computer if the actual mixture is too rich or too lean. Systems are currently being designed to monitor the O2 signal for on-board diagnostic purposes. If the fuel system goes out of range, trouble codes will be logged and the malfunction indicator light will light.

Injector Simulator Interface Some OEM computers monitor the fuel injector drive circuit for pulse width or on-time status. If the PCM does not see that the 8-79 injector circuit is opening and closing, it will log a trouble code and may send the system into “limp mode.” The injector simulator interface modules provide the PCM with a pulse width signal even when the injectors are turned off while running on LPG. Some units incorporate a relay function or injector harness to interface with the OEM system and turn the gasoline injectors on and off for bi-fuel operations. 8-75

Courtesy of Autotronic Controls

F E D C B A A B C D E F CYLINDER SELECT FUNCTION, C BA FOR 6 CYL. ENG. CUT I WIRE LOOP FOR 4 CYL ENG. CUT 2 WIRE LOOPS

F E D C B A +12 VDC GIVES ALTERNATE FUELS MODE AB C D E F +12 VOLTS IGNITION “0” VOLTS GIVES GASOLINE MODE C BA KEY ON (INJECTORS IN) SINGLE DK. BLUE SINGLE RED CONTROL SIGNAL TO TO INJECTORS (OUT) SOLENOID SINGLE PINK LIGHT BLUE TO COMPUTER TIMING REFERENCE SINGLE WHITE ORANGE +12 TO SOLENOID (VIOLET W/WHT) TAN CONNECT TO O2 SENSOR TO KNOCK SENSOR (BLUE) GRAY BLACK ON THE EXHAUST SYSTEM VIOLET EGR COMPUTER SIGNAL (GRAY) CONNECT TO FACTORY 02 COMPUTER CONNECTION DK. BLUE CONNECT TO TPS BLUE CONNECT TO MAP SENSOR WHERE SIGNAL WIRE – MONITORS THE FACTORY GREEN CONNECTOR THROTTLE POSITION WAS DISCONNECTED CONNECT FACTORY GREEN CONNECTOR HERE 8-30 Supplemental electronic interface.

Liquefied Petroleum Gas Training Program PAGE 8-26 Liquefied Petroleum MODULE 8: LPG FUEL SYSTEM OVERVIEW Gas

PROPANE FUEL INJECTION Key Points & Notes FUEL INJECTION SYSTEM OVERVIEW A comprehensive overview of the only LPG fuel injection system currently available to the vehicle conversion market is covered here. 8-80 Refer to Figure 8-31. The system is comprised of a vaporizer/regulator, a combined 8-81 metering valve and computer (compuvalve), gas discharge nozzles, two temperature sensors, and a fuel selector switch (bi-fuel 8-82 applications only). Incorporated into the compuvalve are absolute pressure sensors (fuel and intake manifold) and a fuel temperature sensor. The system operation may be summarized as follows: • Liquid propane from the fuel storage tank(s) flows through a fuel filter to the vaporizer/regulator. • When the fuel lock-off is open, liquid propane flows into the vaporizer heat exchanger where heat from the engine coolant is used to convert the liquid fuel to gas. • The two-stage regulator provides the vaporized propane at a consistent operating pressure to the computerized metering valve (compuvalve). • The compuvalve electronically meters fuel according to demand and controls spark advance for optimum drivability and emissions. A combination of base vehicle and additional sensors a re used to dynamically monitor the engine operating environment to optimize fueling and ignition and provide closed loop control of fueling. • From the compuvalve, fuel flows through low pressure hose and is introduced into the air intake system through the discharge nozzles.

INDICATOR LIGHT 8-83

SELECTOR SWITCH

FILTER VAPORIZER

COMPUVALVE

SPRAY DISKS (throttle body) IAT FUSE & RELAY BOARD

Relief valve vent hose

MST COOLANT MAP LINES takeoff SPRAY BAR (port injection) Courtesy of GFI 8-31 Generalized schematic of fuel injection system.

Liquefied Petroleum Gas Training Program PAGE 8-27 Liquefied Petroleum MODULE 8: LPG FUEL SYSTEM OVERVIEW Gas

• When propane is selected, the compuvalve computer intercepts Key Points & Notes the base vehicle fuel gauge signal and substitutes an appropriate signal to indicate the level of liquid propane in the fuel storage tank(s). In gasoline mode, the normal fuel level sensor signal is passed to the gauge.

Liquefied Petroleum Gas Training Program PAGE 8-28 Liquefied Petroleum MODULE 8: LPG FUEL SYSTEM OVERVIEW Gas

Tank Capacity Vehicle mpg on gasoline (Gallons) Gasoline 5 10 15 20 20 gallons 100 200 300 400 25 125 250 375 500 30 150 300 450 600 35 175 350 525 700 40 200 400 600 800 50 250 500 750 1000 60 300 600 900 1200 80 400 800 1200 1600 100 500 1000 1500 2000 150 750 1500 2250 3000 200 1000 2000 3000 4000

Table 8-1-A Driving range for various tank sizes of gasoline.

Be l o w , post-conversion driving ranges, assuming a 20% increase in fuel consumption: 1) because a gallon of propane has fewer Btus than a gallon of gasoline and, 2), because a gasoline engine is less effi c i e n t running on prop a n e .

Tank Capacity Vehicle mpg on Propane (Gallons) Propane 4 8 12 16 20 gal.WC/16 Actual 64 128 142 256 25 WC/20 80 160 240 320 30 WC/24 96 192 288 384 35 WC/28 112 224 336 448 40 WC/32 128 256 384 512 50 WC/40 160 320 480 640 60 WC/48 192 384 576 768 80 WC/64 256 512 768 1024 100 WC/80 320 640 960 1280 150 WC/120 480 960 1440 1920 200 WC/160 640 1280 1920 2560

Table 8-1-B Driving range for various tank sizes of prop a n e .

Liquefied Petroleum Gas Training Program PAGE 8-29 Liquefied Petroleum MODULE 8: LPG FUEL SYSTEM OVERVIEW Gas

MODULE REVIEW ITEMS

Note to Technician: Consider all choices carefully and select the best answer to each.

1. One approved type of LPG fuel tank is constructed of: A. Iron. B. Kevlar. C. Plastic. D. Aluminum.

2. What information is not listed on the tank data plate? A. Year made. B. Outside diameter (OD). C. Inside Diameter (ID). D. Outside surface area.

3. Which tank and design pressure is not correct? A. Externally mounted fuel tank = 250 psi. B. Internally mounted fuel tank = 225 psi. C. Lift truck tanks = 375 psi. D. Trunk mounted tanks = 312.5 psi.

4. Which of the following appears on the data plate? A. Manufacturer's name and address. B. Manufacturer's trade name of the tank. C. Manufacturer's serial number of the tank. D. Can be all of the above.

5. Which measurement is used to determine the proper size of the pressure relief valve for the tank? A. Outside surface area (SA). B. Tare weight (TW). C. Overall length (OL). D. ASME code symbol.

6. Which components are not protected by the heavy metal guard plate? A. Valves. B. Hose connections. C. Tank fittings. D. Fuel lines.

7. All LPG tanks mounted inside the trunk of a vehicle must: A. Be able to discharge fuel away from passengers in case of collision. B. Have all appurtenances vapor sealed. C. Be covered with a plastic wrap to insulate against condensation. D. Conform to NFPA 53 tank standards.

8. Correct sizing of an LPG fuel tank to the application does not involve: A. Determining the vehicle's physical limitations. B. The type of conversion. C. Maximum driving range. D. Determining the lifespan of the tank.

Liquefied Petroleum Gas Training Program PAGE 8-30 Liquefied Petroleum MODULE 8: LPG FUEL SYSTEM OVERVIEW Gas

9. Passenger car LPG fuel tanks typically hold: A. 5-10 gallons. B. 20-40 gallons. C. 25-115 gallons. D. 10-50 gallons.

10. The maximum allowable tank size operating on highways as determined by NFPA 58 is: A. 200 gallons. B. 250 gallons. C. 300 gallons. D. 500 gallons.

11. LPG tanks are filled to only _____% to allow for thermal expansion. A. 50%. B. 75%. C. Rounded to the nearest $.25 at the pump for convenience when paying. D. 80%.

12. Which tank is not a common size range? A. 7" x 35". B. 10" x 40". C. 14" x 30". D. 24" x 62".

13. The safety factor of LPG tanks is: A. 3:1. B. 6:1. C. 4:1. D. 5:2.

14. LPG weighs _____ than gasoline, by _____ pounds per gallon. A. More; 3.8. B. Less; 5. C. More; .3. D. Less; 2.

15. Which of the following is not an NPPA regulation concerning tank installation in enclosed compartments? A. The tank compartment must be sealed from the passenger compartment. B. The tank compartment must be fitted with LPG vapor leak sensors. C. Tanks should be designed so valves and fittings are routed outside the passenger compartment. D. Suggest the use of tanks with vapor seal covers.

16. If the internal tank pressure becomes excessive, A. The pressure is contained safely up to 3000 psi. B. The pressure is relieved through the pressure relief valve. C. The LPG turns into solid propane. D. An automatic warning system notifies the driver to stop and abandon the vehicle.

Liquefied Petroleum Gas Training Program PAGE 8-31 Liquefied Petroleum MODULE 8: LPG FUEL SYSTEM OVERVIEW Gas

17. The pressure relief valve is positioned: A. Above the liquid in the vapor space. B. Above the liquid in an air pocket. C. Below the liquid. D. Near the bottom of the tank for safe discharge.

18. The pressure relief valve is not labled with the following information: A. Rate of discharge in cubic feet per minute. B. Date of manufacture. C. Manufacture's name. D. Date of last pressure relief episode.

19. The fill valve has a double back check design to: A. Guarantee that if one valve fails, the other one is used as backup. B. Have a back check valve remain in the tank to seal the opening in case of the exposed portion being sheared off. C. Have the higher pressure valve supercede the lower pressure valve in case of overfilling. D. Assist in filling the tank in the direct fill design.

20. Another name for the fixed level gauging device is not the: A. Bleed valve. B. Readout gauge. C. Spit valve. D. Outage valve.

21. What happens when the liquid level in a tank being filled reaches 80% full? A. A white cloud of water vapor spurts out the orifice. B. The propane pump automatically shuts off. C. A white cloud of LPG spurts out of the fill valve. D. The float detects 80% full and shuts off the LPG flow.

22. The fixed level gauge _____ be used when filling the tank _____ the tank is equipped with an automatic stop fill valve. A. Cannot, even if. B. Cannot, although. C. Should, although. D. Must, even if.

23. The service valve provides for: A. Shut off of liquid fuel flow to the engine. B. Shut off of liquid fuel flow to the tank. C. A backup for the fill valve. D. A backup for the pressure relief valve.

24. Check valves are rated from _____ gallons/minute. A. 18-20.1. B. 2.3-4.5. C. 1.7-2.4. D. .8-2.3.

Liquefied Petroleum Gas Training Program PAGE 8-32 Liquefied Petroleum MODULE 8: LPG FUEL SYSTEM OVERVIEW Gas

5. To reset the check valve: A. Turn the withdrawl valve off slowly. B. Turn the withdrawl valve off and wait 10 seconds, then reopen slowly. C. Turn the withdrawl valve slowly until the pressure relief valve resets. D. Activate the service valve, then turn off the withdrawl valve.

26. The fuel gauge uses a _____ to determine a tank's fuel level. A. Lever. B. Pump monitor. C. Level switch. D. Float.

27. If the OEM fuel gauge is used, be sure the sending unti has the same _____ value as the gauge. A. Ohm. B. Capacitance. C. Digital readout. D. PCM.

28. The fuel gauge _____ be used for tank refueling. A. Must always. B. Can. C. Should not. D. Alone is to.

29. _____ is preferred for conversions because it is easily installed, long lasting, and safe. A. Hose. B. Pipe. C. Tubing. D. Conduit.

30. Fuel lines have a safety factor of _____ and must withstand working pressures of _____ psi. A. 4:1, 280. B. 4:1, 350. C. 5:1, 280. D. 5:1, 350.

31. Pipe used in conversions cannot be made of: A. Aluminum. B. Wrought iron. C. Copper. D. Brass.

32. Hose must be: A. All of the following. B. Gasoline and oil resistant. C. Reinforced with stainles steel wire braid. D. Enclosed with an oil resistant outer sheath.

Liquefied Petroleum Gas Training Program PAGE 8-33 Liquefied Petroleum MODULE 8: LPG FUEL SYSTEM OVERVIEW Gas

33. Which is not one of the markings on hose used for fuel lines? A. LP GAS. B. 250 PSI WORKING PRESSURE. C. 1800 PSI BURST PRESSURE. D. PROPANE.

34. Fittings cannot be used if they are made of: A. Malleable iron. B. Ductile iron. C. Steel. D. Cast iron.

35. The start-to-discharge pressure of the hydrostatic relief valve is between: A. 300-350 psi. B. 400-500 psi. C. 300-500 psi. D. 350-400 psi.

36. Which valve vents excessive pressure that may occur if the two shut-off valves are closed? A. The hydrostatic relief valve. B. The fuel lock. C. The automatic stop fill valve. D. The service valve.

37. Which valve permits flow of fuel to the engine only when fuel is required? A. The automatic stop fill valve. B. The service valve. C. The hydrostatic relief valve. D. The fuel lock.

38. Electric fuel lockoffs: A. Are incapable of automatic positive shutoff without a vacuum or oil pressure switch. B. Are capable of automatic positive shutoff even if the power is lost. C. Can function without a vacuum or oil pressure. D. Operate more reliably than vacuum types.

39. Which matierial is not used in the fuel filter element? A. Woven fibers. B. Sintered brass. C. Gauze-like pads. D. Stainless steel mesh.

40. The converter converts _____ pressure LPG into _____ pressure propane vapor. A. Line; low. B. Tank; low. C. Tank; high. D. High; moderate.

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41. In the converter's expansion chamber, as fuel pressure _____, fuel _____, and volume _____. A. Drops; expands; increases. B. Rises; expands; increases. C. Drops; contracts; increases. D. Drops; expands; decreases.

42. The source of heat to keep the converter from "freezing up" is drawn from: A. The electric heater. B. Manifold exhaust. C. Engine coolant. D. An add-on heater unit.

43. A primer is not activated by: A. An electric solenoid. B. A pushbutton. C. An automatic sensor. D. A control valve.

44. Which system requires a primer? A. An old engine. B. A weak engine. C. A rebuilt engine. D. A cold engine.

45. Fuel metering is providing _____ fuel as the amount of air entering the engine _____. A. More; increases. B. Optimum; increases. C. Less; increases. D. More; decreases.

46. Ideal combustion of air and fuel is formally called: A. Stanchiopathy. B. Stoichiometry. C. Equilibrium. D. Perfect combustion.

47. _____ mixes give _____ engine performance; _____ mixes give _____ economy. A. 15% rich; moderate; 15% lean; best. B. 10% lean; best; 10% rich; best. C. 10% rich; moderate; 15% lean; best. D. 10% rich; best; 10% lean; best.

48. Which is a type of air-fuel mixer? A. Venturi. B. Vernacular. C. Air gauge. D. Fuel throttle.

Liquefied Petroleum Gas Training Program PAGE 8-35 Liquefied Petroleum MODULE 8: LPG FUEL SYSTEM OVERVIEW Gas

49. The throttle contols the _____ of air flowing into the engine. A. Expansion. B. Temperature. C. Weight. D. Oxygen %.

50. In the air valve, the _____ the air flow, the _____ the rise of the air valve. A. Lesser; higher. B. Greater; higher. C. Greater; lower. D. More restrictive; overall higher.

51. Gas and air _____ in density as altitude _____. A. Change; changes. B. Increase; increases. C. Decrease; decreases. D. Decrease; increases.

52. When air passes through a venturi, it: A. Increases in pressure. B. Slows down and drops in pressure. C. Speeds up and creates a drop in pressure. D. Slows down to exit though the holes.

53. As the air flow _____, pressure differential _____, and fuel supply _____. A. Increases; increases; increases. B. Decreases; increases; decreases. C. Increases; decreases; increases. D. Increases; increases; increases.

54. Because a venturi mixer has no moving parts, A. It is low maintenance. B. It is still fairly complex in operation. C. It is better than an air mixer. D. It is perferred in conversions over other mixers.

55. Which is not a benefit of closed feedback systems? A. Improved emissions. B. Decreased power. C. Timing changes. D. False code protection.

56. Spark timing may need to be _____, because of the _____ burning speed of LPG. A. Changed, varying. B. Retarded, slower. C. Retarded, increased. D. Advanced, slower.

Liquefied Petroleum Gas Training Program PAGE 8-36 Liquefied Petroleum MODULE 8: LPG FUEL SYSTEM OVERVIEW Gas

57. The timing advance processor is not known as the: A. Recurve module. B. Timing optimizer. C. Dual curve. D. Advance/Retard Unit.

58. The timing delay method: A. Adjusts timing as the engine is loaded. B. Electronically retards timing 15 degrees. C. Advances timing by sampling two gasoline spark events. D. Adjusts timing electronically by retarding 10 degrees.

59. The timing advance method: A. Advances timing by sampling two gasoline spark events. B. Adjusts timing as the engine is loaded. C. Electronically retards timing 15 degrees. D. Adjusts timing advance based on adaptive learning.

60. The timing optimization method: A. Advances timing by sampling two gasoline spark events. B. Electronically retards timing 15 degrees. C. Adjusts timing as the engine is loaded. D. Corrects timing automatically plus or minus 10 degrees.

61. The correct scheme for a feedback system is: A. Input-Feedback-Output \--Processing--/. B. Feedback-Processing-Output \----Input-----/. C. Input-Processing-Output \----Feedback----/. D. Output-Processing-Input \----Feedback----/.

62. What happens if you convert a vehicle, originally equipped with a feedback system, without using an approved equivalent LPG feedback system? A. Federal or state officials issue citations. B. Fine. C. Jail. D. Could be all of the above.

63. The computer ignores most sensor inputs... A. If working properly. B. In closed loop mode. C. In open loop mode. D. Even if they are feeding back information constantly.

64. Fresh air from the air injection pump is directed into the engine exhaust manifold... A. In open loop mode. B. During cold start. C. In closed loop mode. D. During start up.

Liquefied Petroleum Gas Training Program PAGE 8-37 Liquefied Petroleum MODULE 8: LPG FUEL SYSTEM OVERVIEW Gas

65. The computer switches from open loop once the oxygen sensor temperature reaches _____. A. 600 degrees F. B. 550 degrees F. C. 500 degrees F. D. Between 500-600 degrees F.

66. The computer controls the air/fuel ratio: A. In open loop mode. B. In cold start mode. C. In post-cold start mode. D. In closed loop mode.

67. Closed loop is the most efficient way to control which of the following? A. Power. B. Fuel economy. C. Performance. D. All of the above.

68. If the EGO signal is _____ volts, the mixture is _____; if the signal is _____ volts, the mixture is _____. A. 1-1.5; rich; .5-1.0; lean. B. 0-1.5; rich; 1.5-1.8; lean. C. 0-.5; lean; .5-1.0; rich. D. 0-.5; rich; .5-1.5; lean.

69. _____ is the ability to record common drivability conditions. A. Onboard memory. B. Adaptive learn. C. CPU dymanic read. D. Machine learning.

70. _____ are used to avoid false trouble code conditions. A. Electronic interface devices. B. Specialized feedback sensors. C. PCM RS-232 sensor adapters. D. Analog/digital conversion modules.

71. If the PCM finds sensor readings outside the range of gasoline performance, A. The Check Engine light comes on. B. Drivability suffers. C. It logs a trouble code. D. Could be one or more of the above.

72. The _____ generate a gasoline compatible signal to satisfy the _____ diagnostics, while sending the _____ the correct signals with which it can control fuel mixtures. A. Code support modules; LPG ECM; OEM computer. B. Sensors; PCM; LPG ECM. C. Sensors; OEM computer; PCM. D. Code support modules; OEM computer; LPG ECM.

Liquefied Petroleum Gas Training Program PAGE 8-38 Liquefied Petroleum MODULE 8: LPG FUEL SYSTEM OVERVIEW Gas

73. Which sensor monitors the knock sensor curcuit and responds with a correct sensor signal? A. The EGR interface. B. The knock EGR interface. C. The knock sensor signal interface. D. The EGO sensor interface.

74. Which sensor monitors PCM signals related to exhaust gas recirculation and responds with correct sensor signals? A. The knock sensor interface. B. The EGR interface. C. The injector simulator interface. D. The PCM exhaust interface.

75. Which sensor supplies a simulated oxygen feedback signal to the PCM? A. The knock oxygen sensor interface. B. The EGR interface. C. The fuel injector simulator interface. D. The EGO/HEGO sensor interface.

76. Which sensor monitors the fuel injector drive circuit for pulse width or on-time status? A. The injector simulator interface. B. The injector EGO sensor interface. C. The injector EGR simulator interface. D. The EGO/HEGO injector interface.

77. Support modules do not support which functions: A. Code fixes. B. Relays. C. Back fire protection. D. Diagnostics.

Liquefied Petroleum Gas Training Program PAGE 8-39 Liquefied Petroleum MODULE 8: LPG FUEL SYSTEM OVERVIEW Gas

MRI SCORING KEY

1. D 49. C 2. C 50. B 3. B 51. D 4. D 52. C 5. A 53. A 6. D 54. A 7. B 55. B 8. D 56. D 9. B 57. D 10. C 58. B 11. D 59. A 12. A 60. C 13. C 61. C 14. D 62. D 15. B 63. C 16. B 64. B 17. A 65. A 18. D 66. D 19. B 67. D 20. B 68. C 21. A 69. B 22. D 70. A 23. A 71. D 24. C 72. D 25. B 73. C 26. D 74. B 27. A 75. D 28. C 76. A 29. D 77. D 30. D 31. A 32. A 33. C 34. D 35. B 36. A 37. D 38. A 39. D 40. B 41. A 42. C 43. C 44. B 45. A 46. B 47. D 48. A

Liquefied Petroleum Gas Training Program

Liquefied Petroleum MODULE 8: LPG FUEL SYSTEM OVERVIEW Gas

ACTIVITY 8-1: DATA PLATE INFORMATION

OBJECTIVE

To read and interpret propane tank data plates. To identify the specific characteristics of each tank.

MATERIALS NEEDED

Sample tank data plate (Optional- inventory of propane tanks)

METHOD

Given a sample tank data plate by your instructor, provide the following information, or Given a number of propane tanks, locate their data plates and provide the following information.

QUESTIONS

What is meant by Tare Weight? What is meant by Design Pressure, as compared to Working Pressure? What is the maximum psi the tank can be filled to?

Liquefied Petroleum Gas Training Program Liquefied Petroleum MODULE 8: LPG FUEL SYSTEM OVERVIEW Gas

Type of Service: ______

Mfg name/address or trade name: ______

______

Water Capacity (gallons): ______

Design pressure (psi): ______

Tare Weight (pounds): ______

Outside Surface Area (square feet): ______

Manufacturing Date: ______

Shell Thickness (inches): ______

Head Thickness (inches): ______

Overall Length (inches): ______

Outside Diameter (inches): ______

Height-to-Diameter ratio: ______

Mfg's Serial Number: ______

ASME code symbol: ______

Liquefied Petroleum Gas Training Program Liquefied Petroleum MODULE 8: LPG FUEL SYSTEM OVERVIEW Gas

ACTIVITY 8-2: IMPCO MIXER TEARDOWN

OBJECTIVE

To become familiar with and describe the operation of various mixer designs.

MATERIALS NEEDED

One of the following IMPCO mixers: 175, 220, 300, or 425 IMPCO service manual Basic hand tools

METHOD

Using the recommended manufacturer’s service procedures, disassemble and re-assemble a mixer. As the mixer is opened, note the theory of its operation, including the air flow and gas flow through the unit. Determine what if any adjustments that can be made and how they would affect air or gas metering.

QUESTIONS

How does vacuum enter to the upper half of the diaphragm chamber? What adjustments can the technician make on the mixer while it is on the vehicle? Is your mixer tamperproof? How do you know? How does tamperproofing alter the adjustment procedure?

COMMENTS

If possible, obtain a tamperproof mixer for analysis.

Liquefied Petroleum Gas Training Program

Liquefied Petroleum MODULE 8: LPG FUEL SYSTEM OVERVIEW Gas

ACTIVITY 8-3: REGULATOR PRESSURE/VOLUME RELATIONSHIPS

OBJECTIVE

To determine primary and secondary pressure relationships as they relate to gas flow. To adjust an IMPCO PEV regulator. To disassemble and re-assemble a regulator.

MATERIALS NEEDED

IMPCO PEV Regulator 0-10 psi pressure gauge 0-10” water column pressure gauge 0-400 SCHF flow meter Hand-held vacuum pump Basic hand tools

METHOD

Safety Note- Observe standard shop practice with the use of air hoses and connections. Shop line pressure is approximately 120 psi and good judgement should be used. Apply shop air to the high pressure inlet of the PEV regulator. Record the first stage and second stage and flow volume numbers in the table. Adjust the existing spring throughout the full range and observe the effects. Change springs and repeat.

QUESTIONS

What is the minimum and maximum outlet pressures for each spring? How do these values compare to the manufacturer specifications

Liquefied Petroleum Gas Training Program Liquefied Petroleum MODULE 8: LPG FUEL SYSTEM OVERVIEW Gas

TRIAL #1 Spring Color: ______

Primary Secondary Flow Adjustment Pressure Pressure (SCFM) ______High ______

______Low ______

TRIAL #2 Spring Color: ______

Primary Secondary Flow Adjustment Pressure Pressure (SCFM) ______High ______

______Low ______

Liquefied Petroleum Gas Training Program 1 MODULE 8: LPG Fuel System Overview 2 FUEL TANKS AND TANK STANDARDS • Built of steel or aluminum • Must withstand vapor pressures • Must conform to DOT or ASME standards • Use only tanks designed for motor vehicles 3 8-1 DATA PLATE 4 8-2 DATAPLATE 5 FUEL TANKS AND TANK STANDARDS Data plate information: • Type of service • Tank mgf info • Water capacity (lbs or gal.) • Design psi • LPG only wording • Tare weight • Outside surface area 6 FUEL TANKS AND TANK STANDARDS Data Plate Information (continued): • Year made • Shell and head (ends) thicknesses • Overall length (OL) • Outside diameter (OD) • Height to diameter ratio (HD) • Mfg’s serial number • ASME code symbol • Must be visible after tank installation 7 GUARD PLATE • Protects valves and hose connections • Attached securely to the tank • Metal housing "Seal Shell" covers internally mounted tanks 8 SELECTING THE RIGHT DESIGN AND SIZE OF A FUEL TANK • Correctly size the tank to the application • Maximum driving range • Fuel availability • Conversion type • Physical limitations 9 SELECTING THE RIGHT DESIGN AND SIZE OF A FUEL TANK • Range up to maximuim allowed 300 gals. WC • Passenger carrying vehicles limited to 200 gals. WC • Passenger car tanks from 20-40 gals. WC • Commercial vehicle tanks from 25-115 gals. WC • Tanks only filled to 80% to allow thermal expansion • Excess pressure vented by pressure relief valve • Most tanks have 80% automatic stop fill valves 10 SELECTING THE RIGHT DESIGN AND SIZE OF A FUEL TANK • Tank diameters from 12" - 24" • Tank lengths from 30" - 80" • Double tanks; drum tanks • Tank weight factored into conversion design • Heavier tank weight offset by lighter LPG weight 11 FUEL TANK INSTALLATION IN ENCLOSED COMPARTMENTS • Must have working psi of 312.5 • Must have gas tight vapor shield • Optional fixed remote fueling connections • Shield spark producing equipment • Vent compartment at lowest point 12 8-3 TRUNK-MOUNTED TANK FITTINGS 13 FUEL TANK INSTALLATION IN ENCLOSED COMPARTMENTS NFPA 58, 8-2.7:

• Tank compartment must be sealed from passenger compartment • Tanks designed so valves and fittings are routed outside passenger compartment • Suggest tanks with vapor seal covers 14 PROPANE VALVES • Made of brass • Specified for LPG, or specific applications 15 8-4 PROPANE VALVES 16 PRESSURE RELIEF VALVE • Internal spring type valve • Opens automatically if pressure exceeds pressure setting • Spring and valve inside tank to reduce damage • Approved by UL • Opening labeled "RELIEF" • Port positioned in vapor area, not liquid area • Check sizing and presure rating for application 17 PRESSURE RELIEF VALVE Labeling: – CFM discharge rate – Mfg and part number – Mfg date 18 8-5 PRESSURE RELIEF VALVE 19 FILL VALVE • Double back check design to contain liquid if sheared off • Direct fill valve for external tanks • Remote fill valve for internal or limited access tanks • Automatic stop fill valves use either float movement or pressure differential designs 20 8-6 FILL VALVE 21 80% FIXED LIQUID LEVEL GAUGE • Bleed valve, "Spit" valve, Outage valve • Determine when 80% filled • White cloud ofwater vapor spurts out a #54 drill size hole when 80% reached • Manual shutoff valve used with remote fills • Liquid level gauge must still be monitored during filling 22 8-7 BLEEDER VALVE 23 PROPANE LIQUID SERVICE/SHUTOFF VALVE • Shuts off fuel flow to engine • Internal excess flow check valve restricts fuel surges through line • Check valves rated from 1.7-2.4 gals/min. • Checked shut valves must be manually reset • Designed to minimize fuel loss if sheared off 24 8-8 PROPANE LIQUID SERVICE/SHUTOFF VALVE 25 VAPOR SERVICE VALVE • For certain non-automotive applications • Aperture is usually plugged 26 8-9 LIQUID AND VAPOR VALVES 27 FUEL GAUGE • Internal float determines liquid volume • Float arm connected to gauge dial assembly • Direct reading magnetic dial • Sending unit to OEM gauge • Fuel gauge not solely used for refilling to 80% 28 8-10 TANK FLOAT 29 8-11 FUEL GAUGE 30 FUEL LINES, LOCKS, AND FILTERS FUEL LINES • Supplies fuel to carburetion components • Flexible stainless steel wire braided hose common • Hose preferred over pipe and tubing • NFPA 58 Section 8-2.5 Lines and Fittings: – Withstand 350 psi – Safety factor of 5:1 – Burst pressure of 1750 psi 31 8-12 TWO TANK CHECK VALVE 32 PIPE AND TUBING • Wrought iron, steel, brass, copper, polyethylene pipe • Steel, brass, copper, or polyethylene seamless tubing • Heavy walled brass fittings, 45o SAE flare • 37o JIC flares not permitted • May need bending tools and guides, and sealant 33 HOSE • Easily installed • Long lasting • Excellent safety record • Marked "LP GAS, PROPANE, 350 PSI WORKING PRESSURE, 1750 PSI BURST PRESSURE", mfg's name, UL listed for LPG use every 18". • Fittings- 45o SAE flare • Crimped collet-type fittings OK if listed for LPG • Push-on type fittings not permitted 34 8-13 HOSE AND FITTINGS 35 8-14 45o SAE FLARE ELBOW 36 HOSE Ideal Hose: • Gasoline and oil resistant • Non-leaching thermoplastic liner • Reinforced with stainless steel wire braid • Rubber or cloth weave outer sheath • Do not use push-on type hose for fuel lines 37 FITTINGS • Used at hose ends to make connections • High pressure • Brass, steel, copper, malleable or ductile iron • 45o SAE inverted flares only • Two-piece reusable, mandrel-type, or approved crimped collet-type • Straight, 45o, and 90o elbows • Bulkhead straight-throughs, 3-ways, and 4-ways • Do not use push-on type fittings 38 HYDROSTATIC RELIEF VALVE • Installed between two positive shut-off valves • Start-to-discharge pressure between 400-500 psi • Vents excessive liquid pressure from piping if shut-offs close • Protective cap covers discharge outlet 39 8-15 HYDROSTATIC RELIEF VALVE 40 BULKHEAD FITTINGS • Fuel line fittings going through body panels • Straight-through, three-way, and four-way outlets • May connect with hydrostatic relief valve or check valve 41 8-16 BULKHEAD FITTING 42 FUEL LOCK AND AUTOMATIC SHUT-OFF VALVE • Fuel lock or "lock-off" • Opens only when fuel is needed by engine • Vacuum and electrical solenoid types • Required positive shut-off capability • Electrics need vacuum or oil pressure switch 43 8-17 FUEL LOCK AND AUTOMATIC SHUT-OFF VALVE 44 FUEL FILTERS • In-line • Straight through or tee-type • Traps contaminants 45 8-18 FUEL FILTERS 46 CONVERTER VAPORIZER-REGULATOR • Converts high pressure LPG to low pressure vapor 47 LIQUID TO VAPOR • In expansion chamber, metered LPG expands and its volume increases • Circulating engine coolant prevents converter freeze up and inproves efficiency • High pressure valve controlled by a diaphragm reacting to vapor pressure 48 8-19 OHG X-1 CONVERTER CUTAWAY 49 8-20 HIGH-PRESSURE VALVE AND VAPORIZING CHAMBER 50 8-21 OHG X-1 CONVERTER EXPLODED VIEW 51 PRIMERS • Starting aid for some primers • Supplies fuel to mixer and engine via the vapor hose to the air-fuel mixer • Activated only long enough to supply LPG for starting • Used for weak engines 52 VAPOR HOSE • Connects the converter to the air-fuel mixer • Must use hose listed only for this purpose 53 8-22 VAPOR HOSE 54 AIR FUEL MIXERS FUEL METERING THEORY • Carburetor known as air-fuel mixer • Mixes air and fuel in correct ratio • Stoichiometry is ideal combustion of fuel and air • 10% more fuel over ideal ratio is rich; gives best engine performance • 10% less fuel than ideal ratio is lean; gives best economy • Compromise between emissions, performance, economy vs. operating loads and conditions 55 AIR-VALVE MIXERS • Throttle controls weight of air entering engine • Air valve mixer mixes fuel and air before throttle • Air valve assembly meters fuel, compensates for atmospheric changes 56 8-23 AIR VALVE MIXER POSITIONS 57 8-24 AIR VALVE 58 8-25 OHG X-450 EXPLODED VIEW 59 VENTURI PRINCIPLE MIXERS • Air passing through a narrow restriction ("venturi") speeds up, creates drop in pressure • Mounted above or below throttle • Holes or slots below venturi let fuel into air stream and mix with air • Common on small engines • Meters fuel well at fixed engine speeds • No moving parts, low maintenance 60 FUEL SWITCHING AND MONITORING COMPONENTS • Electronics modify the system for improved emissions, power, timing, and false code protection • Excellent electrical connections avoid false readings 61 8-26 FUEL SELECTOR SWITCH 62 TIMING ADAPTATION COMPONENTS • LPG burns slower; timing may need advancing • Use a timing advance processor, recurve module, dual curve, or timing optimizer 63 8-28 DIGITAL SAMPLING TO ADVANCE TIMING 64 TIMING DELAY METHOD • Distributor is physically set 15o advanced • On gasoline, device retards timing 15o • On LPG, timing adjusted 0-15o depending on RPM 65 TIMING ADVANCE METHOD • Advances LPG timing based on sampling two gasoline ignition signals during two spark events • Timing advance for third determined by previous two 66 8-27 IGNITION TIMING CURVE 67 TIMING OPTIMIZATION METHOD • Adjusts as engine is loaded • Works from MAP, or TPS with RPM 68 LPG CLOSED LOOP FEEDBACK SYSTEMS • Computer uses sensor inputs to control engine operation • MUST use equivalent feedback system in conversion if original system was so equipped • Systems interacting with OEM computers and sensors 69 COLD START • Computer ignores sensors, uses predetermined operating conditions from memory • Cold start indicated by engine coolant temp sensor • Fresh air pumped into exhaust manifold to burn off excess fuel until catalytic converter reaches operating conditions 70 COLD START • Engine given predetermined rich fuel mix o •O2 sensor locked out until temp reaches 600 F. • Above 600o computer switches to closed loop • Computer then controls fuel mixtures, fresh air then to catalytic converter or vented 71 8-29 LPG FEEDBACK PROCESSOR 72 STABILIZED ENGINE CLOSED LOOP OPERATION • Computer controls air/fuel ratio from sensor feedback • Allows performance optimization

•O2 sensor is reference control • Lean mixture: EGO .0 - .5 VDC output • Rich mixture: EGO .5 - 1.0 VDC output 73 STABILIZED ENGINE CLOSED LOOP OPERATION • Pressure, air, or fuel then regulated • Systems becoming non-adjustable • Adaptive Learn systems record and recall driving and mixture conditions • Feedback systems improve fuel delivery, response times, and control 74 ELECTRONIC CONVERSION SUPPORT MODULES • OEM PCM looking for sensor signals for gasoline • May operate "Check Engine" light or change drivability • Code support modules interface gasoline signals to LPG signals • DO NOT use illegal or unapproved devices 75 8-30 ELECTRONIC INTERFACE 76 KNOCK SENSOR SIGNAL INTERFACE • Monitors the knock sensor circuit, provides correct signal • Simulated knock signal sent periodically or after knock-generating ignition condition 77 EGR INTERFACE • Monitors PCM exhaust gas recirculation signals • Some send false lean sensors, others force the fuel mixture lean 78 EGO/HEGO SENSOR INTERFACE • Simulates the O2 feedback signal • Some send signal to OEM PCM • Others stop sending signal if actual mixture is bad and let OBD override 79 INJECTOR SIMULATOR INTERFACE • Provides PCM with pulse width signal even if injectors are off when running on LPG 80 PROPANE FUEL INJECTION FUEL INJECTION SYSTEM OVERVIEW Current LPG fuel injection system includes: • Vaporizer/Regulator • Compuvalve (metering valve and computer) – Absolute pressure sensors – Fuel temperature sensors • Gas discharge nozzles • Temperature sensors • Fuel selector switch 81 PROPANE FUEL INJECTION FUEL INJECTION SYSTEM OVERVIEW • LPG from tanks through filter to vaporizer/regulator • From open fuel lock to vaporizer heat exchanger where heated engine coolant changes LPG to gas • Two-stage regulator sends vapor to compuvalve • Compuvalve meters fuel, optimizes spark advance 82 PROPANE FUEL INJECTION FUEL INJECTION SYSTEM OVERVIEW • Sensor readings monitor engine conditions and performance • Fuel from compuvalve through low pressure hose to air intake system via discharge nozzles • If LPG selected, compuvalve interfaces LPG signals to PCM 83 8-31 GENERALIZED SCHEMATIC OF FUEL INJECTION SYSTEM

MODULE 8: LPG Fuel System Overview

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 8-1

FUEL TANKS AND TANK STANDARDS

• Built of steel or aluminum • Must withstand vapor pressures • Must conform to DOT or ASME standards • Use only tanks designed for motor vehicles

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 8-2

8-1 DATA PLATE

Courtesy of NPGA

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 8-3

8-2 DATAPLATE

Photo Copyright Harris Fogel

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 8-4

FUEL TANKS AND TANK STANDARDS

Data plate information: • Type of service • Tank mgf info • Water capacity (lbs or gal.) • Design psi • LPG only wording • Tare weight • Outside surface area

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 8-5

FUEL TANKS AND TANK STANDARDS

Data Plate Information (continued): • Year made • Shell and head (ends) thicknesses • Overall length (OL) • Outside diameter (OD) • Height to diameter ratio (HD) • Mfg’s serial number • ASME code symbol • Must be visible after tank installation

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 8-6

GUARD PLATE

• Protects valves and hose connections • Attached securely to the tank • Metal housing "Seal Shell" covers internally mounted tanks

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 8-7

SELECTING THE RIGHT DESIGN AND SIZE OF A FUEL TANK

• Correctly size the tank to the application • Maximum driving range • Fuel availability • Conversion type • Physical limitations

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 8-8

SELECTING THE RIGHT DESIGN AND SIZE OF A FUEL TANK

• Range up to maximuim allowed 300 gals. WC • Passenger carrying vehicles limited to 200 gals. WC • Passenger car tanks from 20-40 gals. WC • Commercial vehicle tanks from 25-115 gals. WC • Tanks only filled to 80% to allow thermal expansion • Excess pressure vented by pressure relief valve • Most tanks have 80% automatic stop fill valves

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 8-9

SELECTING THE RIGHT DESIGN AND SIZE OF A FUEL TANK

• Tank diameters from 12" - 24" • Tank lengths from 30" - 80" • Double tanks; drum tanks • Tank weight factored into conversion design • Heavier tank weight offset by lighter LPG weight

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 8-10

FUEL TANK INSTALLATION IN ENCLOSED COMPARTMENTS

• Must have working psi of 312.5 • Must have gas tight vapor shield • Optional fixed remote fueling connections • Shield spark producing equipment • Vent compartment at lowest point

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 8-11

8-3 TRUNK-MOUNTED TANK FITTINGS

Photo Copyright Harris Fogel College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 8-12

FUEL TANK INSTALLATION IN ENCLOSED COMPARTMENTS

NFPA 58, 8-2.7:

• Tank compartment must be sealed from passenger compartment • Tanks designed so valves and fittings are routed outside passenger compartment • Suggest tanks with vapor seal covers

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 8-13

PROPANE VALVES

• Made of brass • Specified for LPG, or specific applications

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 8-14

8-4 PROPANE VALVES

Liquid Level Gauge indicates when Pressure Relief Fill Fuel Supply and Manual tank is filled to 80% capacity Valve Valve Shut Off Valve

Fuel Gauge or Sender Unit

Protective Guard Plate

Dataplate

Photo Copyright Harris Fogel College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 8-15

PRESSURE RELIEF VALVE

• Internal spring type valve • Opens automatically if pressure exceeds pressure setting • Spring and valve inside tank to reduce damage • Approved by UL • Opening labeled "RELIEF" • Port positioned in vapor area, not liquid area • Check sizing and presure rating for application

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 8-16

PRESSURE RELIEF VALVE

Labeling: – CFM discharge rate – Mfg and part number – Mfg date

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 8-17

8-5 PRESSURE RELIEF VALVE

Courtesy of Rego

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 8-18

FILL VALVE

• Double back check design to contain liquid if sheared off • Direct fill valve for external tanks • Remote fill valve for internal or limited access tanks • Automatic stop fill valves use either float movement or pressure differential designs

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 8-19

8-6 FILL VALVE

Courtesy of Rego

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 8-20

80% FIXED LIQUID LEVEL GAUGE

• Bleed valve, "Spit" valve, Outage valve • Determine when 80% filled • White cloud ofwater vapor spurts out a #54 drill size hole when 80% reached • Manual shutoff valve used with remote fills • Liquid level gauge must still be monitored during filling

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 8-21

8-7 BLEEDER VALVE

Photo Copyright Harris Fogel

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 8-22

PROPANE LIQUID SERVICE/SHUTOFF VALVE

• Shuts off fuel flow to engine • Internal excess flow check valve restricts fuel surges through line • Check valves rated from 1.7-2.4 gals/min. • Checked shut valves must be manually reset • Designed to minimize fuel loss if sheared off

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 8-23

8-8 PROPANE LIQUID SERVICE/SHUTOFF VALVE

Courtesy of Rego

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 8-24

VAPOR SERVICE VALVE

• For certain non-automotive applications • Aperture is usually plugged

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 8-25

8-9 LIQUID AND VAPOR VALVES

Photo Copyright Harris Fogel

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 8-26

FUEL GAUGE

• Internal float determines liquid volume • Float arm connected to gauge dial assembly • Direct reading magnetic dial • Sending unit to OEM gauge • Fuel gauge not solely used for refilling to 80%

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 8-27

8-10 TANK FLOAT

Photo Copyright Harris Fogel

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 8-28

8-11 FUEL GAUGE

Photo Copyright Harris Fogel

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 8-29

FUEL LINES, LOCKS, AND FILTERS FUEL LINES

• Supplies fuel to carburetion components • Flexible stainless steel wire braided hose common • Hose preferred over pipe and tubing • NFPA 58 Section 8-2.5 Lines and Fittings: – Withstand 350 psi – Safety factor of 5:1 – Burst pressure of 1750 psi

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 8-30

8-12 TWO TANK CHECK VALVE

Tank 1 Tank 2

To Engine

Courtesy of Sherwood

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 8-31

PIPE AND TUBING

• Wrought iron, steel, brass, copper, polyethylene pipe • Steel, brass, copper, or polyethylene seamless tubing • Heavy walled brass fittings, 45o SAE flare • 37o JIC flares not permitted • May need bending tools and guides, and sealant

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 8-32

HOSE

• Easily installed • Long lasting • Excellent safety record • Marked "LP GAS, PROPANE, 350 PSI WORKING PRESSURE, 1750 PSI BURST PRESSURE", mfg's name, UL listed for LPG use every 18". • Fittings- 45o SAE flare • Crimped collet-type fittings OK if listed for LPG • Push-on type fittings not permitted

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 8-33

8-13 HOSE AND FITTINGS

Photo Copyright Harris Fogel

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 8-34

8-14 45o SAE FLARE ELBOW

Photo Copyright Harris Fogel

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 8-35

HOSE

Ideal Hose: • Gasoline and oil resistant • Non-leaching thermoplastic liner • Reinforced with stainless steel wire braid • Rubber or cloth weave outer sheath • Do not use push-on type hose for fuel lines

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 8-36

FITTINGS

• Used at hose ends to make connections • High pressure • Brass, steel, copper, malleable or ductile iron • 45o SAE inverted flares only • Two-piece reusable, mandrel-type, or approved crimped collet-type • Straight, 45o, and 90o elbows • Bulkhead straight-throughs, 3-ways, and 4-ways • Do not use push-on type fittings

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 8-37

HYDROSTATIC RELIEF VALVE

• Installed between two positive shut-off valves • Start-to-discharge pressure between 400-500 psi • Vents excessive liquid pressure from piping if shut-offs close • Protective cap covers discharge outlet

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 8-38

8-15 HYDROSTATIC RELIEF VALVE

Photo Copyright Harris Fogel

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 8-39

BULKHEAD FITTINGS

• Fuel line fittings going through body panels • Straight-through, three-way, and four-way outlets • May connect with hydrostatic relief valve or check valve

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 8-40

8-16 BULKHEAD FITTING

Hydrostatic Relief Valve Trunk floor, bed or frame

Bulkhead fitting To Tank

Nut

Washer Propane Line

To Converter Courtesy of NPGA

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 8-41

FUEL LOCK AND AUTOMATIC SHUT-OFF VALVE

• Fuel lock or "lock-off" • Opens only when fuel is needed by engine • Vacuum and electrical solenoid types • Required positive shut-off capability • Electrics need vacuum or oil pressure switch

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 8-42

8-17 FUEL LOCK AND AUTOMATIC SHUT-OFF VALVE

Courtesy of IMPCO

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 8-43

FUEL FILTERS

• In-line • Straight through or tee-type • Traps contaminants

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 8-44

8-18 FUEL FILTERS

Courtesy of Squibb Taylor

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 8-45

CONVERTER VAPORIZER-REGULATOR

• Converts high pressure LPG to low pressure vapor

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 8-46

LIQUID TO VAPOR

• In expansion chamber, metered LPG expands and its volume increases • Circulating engine coolant prevents converter freeze up and inproves efficiency • High pressure valve controlled by a diaphragm reacting to vapor pressure

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 8-47

8-19 OHG X-1 CONVERTER CUTAWAY

Peter Aschwanden

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 8-48

8-20 HIGH-PRESSURE VALVE AND VAPORIZING CHAMBER

Water (coolant) passage Vaporizing chamber

Underside of body assembly (mid-section) showing high-pressure (primary) regulator valve

Peter Aschwanden

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 8-49

8-21 OHG X-1 CONVERTER EXPLODED VIEW

Peter Aschwanden

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 8-50

PRIMERS

• Starting aid for some primers • Supplies fuel to mixer and engine via the vapor hose to the air-fuel mixer • Activated only long enough to supply LPG for starting • Used for weak engines

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 8-51

VAPOR HOSE

• Connects the converter to the air-fuel mixer • Must use hose listed only for this purpose

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 8-52

8-22 VAPOR HOSE

Photo Copyright Harris Fogel

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 8-53

AIR FUEL MIXERS FUEL METERING THEORY

• Carburetor known as air-fuel mixer • Mixes air and fuel in correct ratio • Stoichiometry is ideal combustion of fuel and air • 10% more fuel over ideal ratio is rich; gives best engine performance • 10% less fuel than ideal ratio is lean; gives best economy • Compromise between emissions, performance, economy vs. operating loads and conditions

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 8-54

AIR-VALVE MIXERS

• Throttle controls weight of air entering engine • Air valve mixer mixes fuel and air before throttle • Air valve assembly meters fuel, compensates for atmospheric changes

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 8-55

8-23 AIR VALVE MIXER POSITIONS

IDLE HALF-THROTTLE FULL THROTTLE

Peter Aschwanden

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 8-56

8-24 AIR VALVE

Courtesy of IMPCO

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 8-57

8-25 OHG X-450 EXPLODED VIEW

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 8-58

VENTURI PRINCIPLE MIXERS

• Air passing through a narrow restriction ("venturi") speeds up, creates drop in pressure • Mounted above or below throttle • Holes or slots below venturi let fuel into air stream and mix with air • Common on small engines • Meters fuel well at fixed engine speeds • No moving parts, low maintenance

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 8-59

FUEL SWITCHING AND MONITORING COMPONENTS

• Electronics modify the system for improved emissions, power, timing, and false code protection • Excellent electrical connections avoid false readings

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 8-60

8-26 FUEL SELECTOR SWITCH

Violet/White - Mode Select Input Propane Black - Fuel Pump Power Output Gasoline Tank Sending Unit

Off Blue - Fuel Pump Power Input Red - Controller Power Output OEM Fuel Gauge LPG Tank Sending Unit Gasoline Brown - Lock-off Power Unit

Courtesy of Algas Carburetion

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 8-61

TIMING ADAPTATION COMPONENTS

• LPG burns slower; timing may need advancing • Use a timing advance processor, recurve module, dual curve, or timing optimizer

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 8-62

8-28 DIGITAL SAMPLING TO ADVANCE TIMING

Fred Moreno

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 8-63

TIMING DELAY METHOD

• Distributor is physically set 15o advanced • On gasoline, device retards timing 15o • On LPG, timing adjusted 0-15o depending on RPM

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 8-64

TIMING ADVANCE METHOD

• Advances LPG timing based on sampling two gasoline ignition signals during two spark events • Timing advance for third determined by previous two

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 8-65

8-27 IGNITION TIMING CURVE

Courtesy Autotronic Controls College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 8-66

TIMING OPTIMIZATION METHOD

• Adjusts as engine is loaded • Works from MAP, or TPS with RPM

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 8-67

LPG CLOSED LOOP FEEDBACK SYSTEMS

• Computer uses sensor inputs to control engine operation • MUST use equivalent feedback system in conversion if original system was so equipped • Systems interacting with OEM computers and sensors

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 8-68

COLD START

• Computer ignores sensors, uses predetermined operating conditions from memory • Cold start indicated by engine coolant temp sensor • Fresh air pumped into exhaust manifold to burn off excess fuel until catalytic converter reaches operating conditions

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 8-69

COLD START

• Engine given predetermined rich fuel mix o •O2 sensor locked out until temp reaches 600 F. • Above 600o computer switches to closed loop • Computer then controls fuel mixtures, fresh air then to catalytic converter or vented

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 8-70

8-29 LPG FEEDBACK PROCESSOR

Mount Install 3/16” Throttle position sensor solenoid here vacuum line To mixer valve Back-check vacuum port 6”-8” WC valve with orifice Fuel control valve TPS ground TPS signal

Gray Violet wire wire

Blue wire control signal

Orange wire +12v to solenoid To factory computer

Cut 1 loop for six cylinder vehicles For monitoring Oxygen Cut 2 loops for 4 cylinder vehicles actual O2 signal sensor

Green wire

Courtesy Autotronic Controls College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 8-71

STABILIZED ENGINE CLOSED LOOP OPERATION

• Computer controls air/fuel ratio from sensor feedback • Allows performance optimization

•O2 sensor is reference control • Lean mixture: EGO .0 - .5 VDC output • Rich mixture: EGO .5 - 1.0 VDC output

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 8-72

STABILIZED ENGINE CLOSED LOOP OPERATION

• Pressure, air, or fuel then regulated • Systems becoming non-adjustable • Adaptive Learn systems record and recall driving and mixture conditions • Feedback systems improve fuel delivery, response times, and control

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 8-73

ELECTRONIC CONVERSION SUPPORT MODULES

• OEM PCM looking for sensor signals for gasoline • May operate "Check Engine" light or change drivability • Code support modules interface gasoline signals to LPG signals • DO NOT use illegal or unapproved devices

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 8-74

8-30 ELECTRONIC INTERFACE

Courtesy of Autotronic Controls

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 8-75

KNOCK SENSOR SIGNAL INTERFACE

• Monitors the knock sensor circuit, provides correct signal • Simulated knock signal sent periodically or after knock-generating ignition condition

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 8-76

EGR INTERFACE

• Monitors PCM exhaust gas recirculation signals • Some send false lean sensors, others force the fuel mixture lean

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 8-77

EGO/HEGO SENSOR INTERFACE

• Simulates the O2 feedback signal • Some send signal to OEM PCM • Others stop sending signal if actual mixture is bad and let OBD override

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 8-78

INJECTOR SIMULATOR INTERFACE

• Provides PCM with pulse width signal even if injectors are off when running on LPG

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 8-79

PROPANE FUEL INJECTION FUEL INJECTION SYSTEM OVERVIEW

Current LPG fuel injection system includes: • Vaporizer/Regulator • Compuvalve (metering valve and computer) – Absolute pressure sensors – Fuel temperature sensors • Gas discharge nozzles • Temperature sensors • Fuel selector switch

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 8-80

PROPANE FUEL INJECTION FUEL INJECTION SYSTEM OVERVIEW

• LPG from tanks through filter to vaporizer/ regulator • From open fuel lock to vaporizer heat exchanger where heated engine coolant changes LPG to gas • Two-stage regulator sends vapor to compuvalve • Compuvalve meters fuel, optimizes spark advance

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 8-81

PROPANE FUEL INJECTION FUEL INJECTION SYSTEM OVERVIEW

• Sensor readings monitor engine conditions and performance • Fuel from compuvalve through low pressure hose to air intake system via discharge nozzles • If LPG selected, compuvalve interfaces LPG signals to PCM

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 8-82

8-31 GENERALIZED SCHEMATIC OF FUEL INJECTION SYSTEM

Indicator light

Selector switch

Filter Vaporizer

Compuvalve Spray Disks (throttle body) IAT

Fuse & relay board

MST Coolant lines MAP Spray bar takeoff Relief valve vent hose (port injected) Courtesy of GFI

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 8-83

MODULE 9: Safety and Regulations

State of Oklahoma College of the Desert West Virginia University

Liquefied Petroleum MODULE 9: SAFETY AND REGULATIONS Gas

CONTENTS

OBJECTIVES...... 9-i INSTRUCTOR NOTES ...... 9-ii REVIEW THE PROPERTIES OF LPG...... 9-1 SAFETY PROCEDURES FOR INSTALLING AND SERVICING LPG EQUIPMENT...... 9-1 SAFETY PROCEDURES FOR HANDLING PRESSURIZED GASES ...... 9 - 2 FACILITY SAFETY MODIFICATIONS ...... 9-2 SAFETY NOTES & WARNINGS...... 9-3 NPFA 58 HIGHLIGHTS...... 9-5 PERSONAL LIABILITY...... 9-6 MODULE REVIEW ITEMS ...... 9-7 MRI SCORING KEY ...... 9-9 ACTIVITY 9-1: SCHOOL BUS CONVERSION PROBLEM HANDOUT: SUBURBAN PROPANE MATERIAL SAFETY DATA SHEET HANDOUT: NFPA 58 STANDARD FOR THE STORAGE AND HANDLING OF LIQUEFIED PETROLEUM GASES OVERHEAD TRANSPARENCY MASTERS

Liquefied Petroleum Gas Training Program

PAGE 9-i Liquefied Petroleum MODULE 9: SAFETY AND REGULATIONS Gas

OBJECTIVES

At the completion of this module, the technician will be able to: • Review the properties of LPG. • Identify the safety procedure for installing and servicing LPG equipment. • Describe the safety procedure when handling pressurized gases. • Explain the facility safety modifications necessary when handling pressurized gases. • Identify sppecific safety warnings. • Review liability issues. • Discuss NFPA 58, and review its highlights.

Liquefied Petroleum Gas Training Program PAGE 9-ii Liquefied Petroleum MODULE 9: SAFETY AND REGULATIONS Gas

INSTRUCTOR NOTES

INSTRUCTOR MATERIALS/MEDIA NEEDED Overhead projector or LCD panel/projection equipment Master overhead transparencies or Microsoft PowerPoint 4.0 presentation file Mod9.ppt

Note: Slides correspond to text as indicated by icon

VCR with TV or projection unit

Laboratory Activities: Activity 9-1: School Bus Conversion Problem

Note: Lab activities correspond to text as indicated by icon

Handouts: Suburban Propane Material Safety Data Sheet NFPA 58 Standard for the Storage and Handling of Liquefied Petroleum Gases

Note: Handouts correspond to text as indicated by icon

STUDENT MATERIALS/MEDIA NEEDED Module 9: Safety and Regulations

OVERHEAD TRANSPARENCY MASTERS The printouts enclosed with this module are taken from the Microsoft PowerPoint 4.0 presentation file Mod9.ppt . Instructors planning to use overhead projectors should make transparencies from these printouts on a copier or laser printer designed to safely print to acetate.

Note: Please review Module 25: Training of Trainers for more hints on instructional needs and strategies.

Liquefied Petroleum Gas Training Program PAGE 9-1 Liquefied Petroleum MODULE 9: SAFETY AND REGULATIONS Gas

REVIEW THE PROPERTIES OF LPG Key Points & Notes Technicians should know and understand the properties, uses, and safety precautions of LPG before working with the gas or associated 9-2 equipment or both. Propane is one of the lightest, simplest hydrocarbons. Because propane has such a simple chemical structure, it is among the cleanest of any alternative fuels. The makeup of LP gas can vary, 1. LPG CAN COLLECT IN but the common forms include propane, butane, FLOOR PITS, WATE R / and butane/propane mixes. Propane is odorless, so OIL SEPAR A TORS, IN an artificial smell is added. It is non-toxic. LPG is BUCKETS AND BOXES, slightly heavier than air; thus, LPG can collect in AND NEAR PILOT LIGHT sewers and other low areas. LPG can be dispersed AND BURNERS AT into the air with the aid of wind or ventilation FLOOR LEVEL. systems. Initial releases of LPG expand from a 2. SMALL AMOUNTS OF liquid state to a gaseous state with a volume LIQUID PROPAN E increase of about 270 times. Ambient temperature EX P AND TO A LOT OF LPG liquid absorbs heat from the surrounding air as it vaporizes VAP O R . (i.e., heat of vaporization), causing the air/vapor mixture to be cold. The vapors are heaviest when they are cold and will disperse more Suburban Propane easily as they are warmed to ambient temperature. Properly Material Safety Data controlled combustion can lower vehicle emissions well below Sheet gasoline. However, it is never safe to run an engine in an enclosed area (such as a shop) without proper ventilation. NFPA 58 Standard for the Storage and SAFETY PROCEDURES FOR INSTALLING AND SERVICING LPG Handling of Liquefied EQUIPMENT Petroleum Gases LPG is stored as a liquid under pres s u r e and when it is exposed to air it vaporizes. During the vaporization process, LPG extracts heat 9-3 fr om the surrounding air and anything in that air. Theref o r e, gloves should be worn when refueling because skin contact with an LPG leak can cause frostbite. High concentrations of LPG displace oxygen levels that can cause asphyxiation, with early symptoms of dizziness. No harmful long-te r m effects have been reported from ex p o s u r e to propane vapors. Storage and maintenance facilities must be designed to include ventilation. Fuel tanks certified by the American Society of Mechanical Engineers (ASME) are used to store LPG under pressure in 9-4 LPG-fueled vehicles. As with all fuel tanks, the possibility of LPG tank explosions does exist under extreme conditions. These conditions are present when high vaporization rates build pressure faster than the pressure relief system can lower it (e.g., fire engulfs the tank), or pressure relief equipment is not functional (e.g., the tank is physically rolled over such that liquid is vented through the relief system rather than vapors). LPG tanks are safe because of the many safety features designed into them, including the following: • LPG tanks are designed and built to withstand 1000 psi even though normal LPG operating pressures are only 130 to 170 psi. As a result, LPG tanks are less likely to rupture than conventional gasoline tanks. • LPG tanks are designed to be filled to only 80 percent capacity to allow for gas expansion due to temperature increase.

Liquefied Petroleum Gas Training Program PAGE 9-2 Liquefied Petroleum MODULE 9: SAFETY AND REGULATIONS Gas

• LPG tank ruptures from external damage are not likely to result Key Points & Notes in an explosion because tank pressure will be vented at the rupture point. • Ignition inside a tank is highly unlikely because no oxygen is present. • Propane vehicle tanks are constructed from carbon steel under a code developed by the American Society of Mechanical Engineers (ASME). A propane tank is 20 times more puncture-resistant than a typical gasoline tank. In addition, a properly installed propane tank can actually add to the structural strength of a vehicle. Note: ASME motor fuel tanks should not be stored containing fuel. • The Research Institute for Road Vehicles (Delft, Netherlands) has conducted extensive vehicle crash testing with propane-fueled vehicles. In these tests, propane storage tanks did not leak, even when the vehicles were severely damaged. In addition to crash testing, the Institute conducted fire testing in which the propane tanks were exposed to bonfire and extreme heat. Once again, the propane tanks did not fail. Tanks should be assigned to a definite, isolated area for fuel storage and the area should be posted with the name of the gas stored. The 9-5 ar ea should be dry, cool and well ventilated, and preferably fire resistant. Tanks should be protected from excessive temperatures by storing them away from radiators or other sources of heat. In general, tanks must be secured while in storage. Tanks containing LPG should be stored away from other combustible materials. Empty and full tanks should be stored separately and properly labeled. SAFETY PROCEDURES FOR HANDLING PRESSURIZED GASES Training of industry personnel who handle propane has long been in existence. Effective January 13, 1995, all employees employed in 9-6 handling LPG shall be trained in proper handling and operating procedures, which the employer shall document (NFPA 58, 1-5 1995). The National Propane Gas Association has enhanced these training procedures to develop a uniform, nationally recognized training program for tasks involving handling propane, its equipment and appliances. The Certified Employee Tr a i n i n g Program (CETP) continues to train personnel in handling propane gas. Similar training programs, such as this one you are taking, are being developed for propane motor fuel technicians. FACILITY SAFETY MODIFICATIONS Like any other energy source, LPG requires careful handling to avoid mishaps. When working with or around LPG, keep the 9-7 following potential hazards in mind. Escaping propane could lead to one or more of the following incidents: fire due to ignition of a combustible mixture of gas and air, explosion due to ignition of combustible mixture of gas and air in a confined space; asphyxiation due to the lack of oxygen. If escaping gas is encountered, all possible sources of ignition must be considered and eliminated or controlled. In addition, sources of ignition should be eliminated within 25 feet of refueling sites.

Liquefied Petroleum Gas Training Program PAGE 9-3 Liquefied Petroleum MODULE 9: SAFETY AND REGULATIONS Gas

Do not remain in a propane-rich atmosphere for any prolonged Key Points & Notes length of time. Propane vapors are non-toxic, but they can reduce the oxygen content in a vapor cloud or enclosed space. In an atmosphere with high concentrations of propane vapor, a person could become unconscious. Standards for the installation and operation of propane dispensers are contained in a publication produced by the National Fire Protection Association, NFPA 58, Standard for the Storage and Handling Liquefied Petroleum Gases. Various state and local codes may also apply to these operations. SAFETY NOTES & WARNINGS Note: These Safety Notes & Warnings are courtesy of GFI Systems. • Important Safety Notice: Appropriate service methods and proper repair procedures are required for safe, reliable operation 9-8 of motor vehicles as well as the safety of the technicians performing maintenance procedures.

ALWAYS DISCONNECT BATTERY: • When disconnecting the battery, disconnect BOTH terminals. Disconnect the negative (–) side first. 9-9 • When installing new equipment on vehicle. • When making electrical connections. • When disconnecting electrical connections. • When testing circuits for electrical continuity.

FOR YOUR SAFETY: • Set parking brake when vehicle is stopped. • Use safety stands when working under vehicle. 9-10, 9-11 • Keep clothing and yourself away from moving parts when the engine is running. • Remove jewelry and loose clothing before beginning to work on vehicle. • Always wear safety glasses for eye protection. • Do not attempt to lift or move tank cylinders or other heavy objects alone. Use at least two people. Wear proper lifting support braces. Use lifting devices when available. • Keep work area clean and free of oil and debris.

WORKING AND OPERATING THE VEHICLE • Do not smoke while working on a vehicle or in the service area. •To prevent serious burns, avoid contact with hot metal parts 9-12, 9-13 such as the radiator, exhaust manifold, tail pipe, catalytic converter, and muffler. • Operate the engine only in a well-ventilated area to avoid the danger of carbon monoxide. • Cover all exposed engine openings when removing parts from vehicle (e.g., upper manifold). Use a clean lint-free cloth or plastic.

Liquefied Petroleum Gas Training Program PAGE 9-4 Liquefied Petroleum MODULE 9: SAFETY AND REGULATIONS Gas

Key Points & Notes

9-28

9-29

9-34

Courtesy of NFPA 9- 1 LPG warning and fuel identification labels.

•Work on parts removed from vehicle should be done on a covered, non-abrasive surface. • Do not step on bumpers or fenders. • Cover fenders and bed floor and exposed surfaces that may be touched during work on vehicle. WARNINGS: • When fueling or venting propane, extinguish all smoking material and shut off engine. 9-14, 9-15 • Vent fuel only in a well ventilated area and follow local regulations concerning off-loading propane gas. Consult your local fire and environmental authorities for specific regulations. • Do not attempt to remove or disassemble propane components while system is pressurized. •Tanks should not be installed with a quantity of fuel loaded. Do not open valves until system is installed or valve ports are otherwise sealed. • Do not use damaged or broken parts and components. JACKING OR LIFTING: Most vehicles may be lifted using normal jacking procedures as described in the OEM owner’s manual. It is important that the 9-16 following additional steps are observed. • DO shutoff all tank valves before lifting. • DO NOT use the propane gas components (e.g., tanks, tank brackets, covers, and fuel lines) as lift or contact points.

Liquefied Petroleum Gas Training Program PAGE 9-5 Liquefied Petroleum MODULE 9: SAFETY AND REGULATIONS Gas

TOWING A CONVERTED VEHICLE Key Points & Notes Converted vehicles can be towed using normal towing procedures. Please observe the following additional steps. • DO shutoff all tank valves before lifting or towing. • DO NOT attach tow bars, towing chains or safety chains to the propane gas components (e.g., tanks, tank brackets, covers and fuel lines). • DO NOT allow tow bars, towing chains or safety chains to rest or rub against the propane gas components. • For vehicles equipped with a tank aft of the rear axle, DO NOT tow from the rear. Tow from the front.

VEHICLES INVOLVED IN ACCIDENTS Vehicles involved in an accident that may cause damage to the propane gas components must be inspected and certified before being returned to service. This includes tank inspection and leak testing as well as system integrity and function. NPFA 58 HIGHLIGHTS 9-17 The following outline highlights Chapters and Sections of NPFA 58 that apply to LPG motor fuel work. These NPFA guidelines are for 9-18 general safety and do not necessarily supercede other local, state, or federal regulations. They are the minimum standards related to safety – not emissions or vehicle perfo r mance (NFPA 58, 1995 9-19 Ed i t i o n ) . Chapter 1 General provisions 9-20 - 9-25 A. 1-5 Qualification of personnel Chapter 3-7 Ignition control A. 3-7.2 Electrical equipment B. 3-7.3 Other sources of ignition Chapter 3-9 Vehicle fuel dispenser and dispensing stations A. 3-9.3 General installation provisions. B. 3-9.4 Installation of vehicle fuel dispensers Chapter 3-10 Fire protection A. 3-10.2 General 1. 3-10.2.5 Fire extinguisher (#18) 2. 3-10.2.6 LPG fires shall not normally be extinguished until source of fuel is shut off. 3. 3-10.2.7 Emergency controls Chapter 4 Lp-gas liquid transfer A. 4-2.1.1 Transfer personnel shall be in attendance during the entire transfer operation B. 4-2.3 Arrangement and operation of transfer systems 1. 4-2.3.2 Sources of ignition shall be controlled 2. 4-2.3.2 (a) Internal combustion engines (15’) 3. 4-2.3.2 (b) Smoking, open flames, electrical tools & lights (2 5 ’ )

Liquefied Petroleum Gas Training Program PAGE 9-6 Liquefied Petroleum MODULE 9: SAFETY AND REGULATIONS Gas

4. 4-2.3.2 (6) Sources of ignition, pilot lights, burners, Key Points & Notes electric ignition devices. (common cause of accidents associated with rec. veh.) 5. 4-4.3 Compliance with maximum permitted filling limit provisions. Chapter 8 Engine fuel systems A. 8-1.4 Properly trained (and licensed, where required) 9-26, 9-27 B. 8-2 General purpose vehicle engines fueled by Lp-gas 1. 8-2.2 Containers 2. 8-2.2(c) Container markings 3. 8-2.2(d)(e) Aggregate water capacity 4. 8-2.2(g) Container labeling C. 8-2.3 Container appurtenances 1. 8-2.3(a)4&5 Internal or flush-type relief valve 2. 8-2.3(a)8. Automatic stop fill valve (Jan. 1,1984 and on) D. 8-2.4 Carburetion equipment 8-2.4(b)4 Engine exhaust gas, heat for vaporizer 9-30 - 9-33 8-2.4(d) Automatic shut off valve or equivalent E. 8-2.5 Piping, hose and fittings 8-2.5(d)1. Hose, hose connections, and flexible connectors (stainless steel only) 8-2.5(d)1.A. Hose markings F. 8-2.6 Installation of containers and container appurtenance 8-2.6(d) Container locations with respect to vehicle 8-2.6(i)1. to 4. Relief valve pipe away requirements G. 8-2.7 Containers mounted in the interior of vehicles 8-2.7(a)1.& 2. Gas-tight integrity 8-2.7(b) Permanently mounted remote fill H. 8-2.8 Pipe and hose installation 8-2.8(h) Hydrostatic relief valve requirements I. 8-2.9 Equipment installation 8-2.9(a) Manufacturer’s recommendations J. 8-2.10 Marking (black diamond) Activity 9-1: School K. 8-6(a)(b)(c) Garaging of vehicles, residential garages and Bus Conversion sources of ignition Problem PERSONAL LIABILITY All combustible gases can be dangerous once the handler loses co n t r ol of the fuel. Casual, careless handling is foolish. You, the 9-35 ha n d l e r , are responsible for the work you perfo r m on and around the vehicle and its fuel. Responsible means liable, which also means law suits and personal loss. The best insurance policies are common sense, safe handling, and integrity of the fuel system and yourself.

Liquefied Petroleum Gas Training Program Liquefied Petroleum MODULE 9: SAFETY AND REGULATIONS Gas

ACTIVITY 9-1: SCHOOL BUS CONVERSION PROBLEM

OBJECTIVE

To reference NFPA 58 and locate regulations concerning installations.

MATERIALS NEEDED

NFPA 58, 1995 or current version

QUESTION

You are in the design phase of a conversion of a school bus to LPG. Your customer is a school district in the state of Texas. There is a question about the venting of the fuel tanks. Determine and explain the proper design of the installation of the fuel tanks according to NFPA 58 in the space below.

______

Liquefied Petroleum Gas Training Program

PAGE 9-9 Liquefied Petroleum MODULE 9: SAFETY AND REGULATIONS Gas

MODULE REVIEW ITEMS

Note to Technician: Consider all choices carefully and select the best answer to each. 1. Which of the following safety precautions should be taken when handling LPG? A. Gloves should be worn when refueling. B. Always refuel in an enclosed area. C. Only fill a fuel tank to 80% of its capacity. D. A and C.

2. One propane characteristic is that it is heavier than air. What potential dangers can this cause? A. Ignite upon contact with the air. B. Has the potential to collect in low lying areas. C. Freeze upon contact with air. D. Disperse readily into the air.

3. What happens when pressurized LPG is exposed to air? A. It explodes. B. It extracts heat from the surrounding air. C. It vaporizes. D. B & C.

4. What organization certifies LPG tanks? A. Local filling stations. B. State inspectors. C. American Society of Mechanical Engineers (ASME). D. National Propane Gas Association.

5. Why are LPG tanks considered to be safe? A. Tanks are designed to withstand 1000 psi. B. Tanks are designed to be filled only to 80 percent capacity. C. Tanks are constructed from carbon steel and are highly puncture resistant. D. All of the above.

6. Propane industry personnel are required to be certified in handling propane gas. A. True. B. False.

7. What is one of the first things to do if a LPG leak was to occur? A. Close all doors and windows immediately to stop ventilation. B. Release any excess LPG in the tank. C. Eliminate all possible sources of ignition. D. Cool the area as much as possible.

8. Which of the following should LPG technicians be familiar with? A. Properties of LPG. B. Uses of LPG. C. Safety precautions necessary to work with LPG. D. All of the above.

Liquefied Petroleum Gas Training Program PAGE 9-10 Liquefied Petroleum MODULE 9: SAFETY AND REGULATIONS Gas

9. Why is propane among the cleanest of all alternative fuels? A. Propane has a simple chemical structure. B. Propane gas can be liquefied. C. Propane is one of the lightest, simplest hydrocarbons. D. A and D.

10. High concentrations of LPG can reduce oxygen levels that can cause: A. Fires. B. Asphyxiation. C. Harmful long-term side effects. D. None of the above.

11. Where should LPG tanks be stored? A. In a dry, cool, well ventilted area. B. Securely while in storage, away from other combustibles. C. In an area protected from excessive heat. D. All of the above.

12. In what publication can standards for installation and operation of propane dispensers be found? A. Journal of LP Gas. B. American Society of Mechanical Engineers. C. National Fire Protection Agency (NPGA 58). D. National Propane Gas Agency Journal.

Liquefied Petroleum Gas Training Program PAGE 9-11 Liquefied Petroleum MODULE 9: SAFETY AND REGULATIONS Gas

MRI SCORING KEY

1. D 2. B 3. D 4. C 5. D 6. A 7. C 8. D 9. D 10. B 11. D 12. C

Liquefied Petroleum Gas Training Program

1 MODULE 9: Safety and Regulations 2 REVIEW THE PROPERTIES OF LPG • Made of propane, butane, and mixes of both • Added artificial smell • Harmful if inhaled in place of oxygen • Heavier than air- 1.5 specific gravity • Dispersable into air with wind or vent systems • Expands from liquid state to gaseous state with volume increase of 270x • Absorbs heat from air as it vaporizes • Lower exhaust emissions than gasoline 3 SAFETY PROCEDURES FOR INSTALLING AND SERVICING LPG EQUIPMENT • Wear gloves during refueling • Causes asphyxiation in high concentrations • Vent facilities properly 4 SAFETY PROCEDURES FOR INSTALLING AND SERVICING LPG EQUIPMENT Fuel Tanks: • Can explode under extreme conditions or faulty pressure relief systems • Withstand 1000 psi • Fill to only to 80% • Ruptures will probably be leaks vs. explosions • No ignition inside tank- no oxygen present inside • Made of carbon steel; very puncture resistant, adds to vehicle structural strength, crash worthy 5 SAFETY PROCEDURES FOR INSTALLING AND SERVICING LPG EQUIPMENT Tank Storage: • Store empties in designated conspicuous, secured, isolated area • Area should be dry, cool, vented, fire resistant • Tanks with LPG should be stored away from combustibles • Separate and label empty & full tanks 6 SAFETY PROCEDURES FOR HANDLING PRESSURIZED GASES • All employees will be trained in proper handling and operating procedures • NPGA national training program for handling, equipment, and appliances • Certified Employee Training Program (CERT) 7 FACILITY SAFETY MODIFICATIONS • Potential hazards: – Fire – Explosion – Asphyxiation • Eliminate ignition sources from within 25’ of refueling sites • See NFPA #58 for LPG dispenser installation and operation • Check state and local codes 8 SAFETY NOTES AND WARNINGS NOTICE

Appropriate service methods and proper repair procedures are required for safe, reliable operation of motor vehicles as well as the safety of the technicians performing maintenance procedures 9 DISCONNECT BATTERY • Negative (-) first then positive (+) • When installing new equipment • When making electrical connections • When disconnecting electrical connections 10 PERSONAL SAFETY • Set parking brake when vehicle is stopped • Use safety stands when working under vehicle • Keep clothing and oneself away from moving parts when the engine is running • Remove jewelry and loose clothing before working on vehicle • Always wear safety glasses for eye protection 11 PERSONAL SAFETY • Do not lift or move tanks or other heavy objects alone – Use at least two people – Wear proper lifting support braces – Use lifting devices when available 12 WORKING ON AND OPERATING THE VEHICLE • No smoking around vehicle • Avoid skin contact with hot metal parts (radiator, exhaust manifold, tail pipe, catalytic converter and muffler) • Operate the engine only in well-ventilated area • Cover all exposed openings when removing parts from vehicle with clean lint- free cloth or plastic 13 WORKING ON AND OPERATING THE VEHICLE • Work on parts removed from vehicle on a covered, non-abrasive surface • Do not step on bumpers or fenders • Cover fenders, bed floor and exposed surfaces that may betouched during work on vehicle 14 WARNINGS • Stop smoking, shut off engine when fueling or venting propane • Vent fuel only in well ventilated area. Consult local authorities for specific off- loading regulations • Do not attempt to remove or disassemble propane components while system is pressurized 15 WARNINGS • Tanks may be installed with a quantity of fuel loaded. – Do not open valves until system is installed or valve ports are sealed • Do not use damaged or broken parts and components 16 JACKING OR LIFTING THE VEHICLE • See OEM owner's manual for jacking information • DO shutoff all tank valves before lifting • DO NOT use propane gas components (tanks, tank brackets, covers, fuel lines) as lift or contact points 17 TOWING A CONVERTED VEHICLE • Converted Vehicles OK to tow • DO shutoff all tank valves before lifting or towing • DO NOT attach tow bars, towing chains or safety chains to propane gas components (tanks, tank brackets, covers, fuel lines) • DO NOT allow tow bars, towing chains or safety chains to rest or rub against propane gas components • DO NOT tow vehicles equipped with a tank aft of the rear axle from the rear- tow from front 18 VEHICLES INVOLVED IN ACCIDENTS • Damaged vehicles may have damage to LPG components • Inspect and certify components and system integrity before returning vehicle to service • Inspect and leak check tank 19 NFPA #58 HIGHLIGHTS • Following highlights pertain to LPG motor fuel work • Minimal standards for general safety • May not supercede local, state, or federal regulations 20 CHAPTER 1 GENERAL PROVISIONS A. 1-5 Qualification of personnel 21 CHAPTER 3-7 IGNITION CONTROL A. 3-7.2 Electrical equipment B. 3-7.3 Other sources of ignition 22 CHAPTER 3-9 VEHICLE FUEL DISPENSER AND DISPENSING STATIONS A. 3-9.3 General installation provisions B. 3-9.4 Installation of vehicle fuel dispensers 23 CHAPTER 3-10 FIRE PROTECTION A. 3-10.2 General 1. 3-10.2.5 Fire extinguisher (#18) 2. 3-10.2.6 LPG fires shall not normally be extinguished until source of fuel is shut off 3. 3-10.2 .7 Emergency controls 24 CHAPTER 4 LPG LIQUID TRANSFER A. 4-2.1.1 Transfer personnel shall be in attendance during the entire transfer operation B. 4-2.3 Arrangement and operation of transfer systems 1. 4-2.3.2 Sources of ignition shall be controlled 2. 4-2.3.2 (a) Internal combustion engines (15') 3. 4-2.3.2 (b) Smoking, open flames, electrical tools & lights (25') 25 CHAPTER 4 LPG LIQUID TRANSFER B. 4-2.3 Arrangement and operation of transfer systems 4. 4-2.3.2 (6) Sources of ignition, pilot lights, burners, electric ignition devices 5. 4-4.3 Compliance with maximum permitted filling limit provisions 26 CHAPTER 8 ENGINE FUEL SYSTEMS A. 8-1.4 Properly trained (and licensed, where required) B. 8-2 General purpose vehicle engines fueled by LPG 1. 8-2.2 Containers 2. 8-2.2(c) Container markings 3. 8-2.2(d)(e) Aggregate water capacity 4. 8-2.2(g) Container labeling 27 CHAPTER 8 ENGINE FUEL SYSTEMS C. 8-2.3 Container appurtenances 1. 8-2.3(a)4&5 Internal or flush-type relief valve 2. 8-2.3(a)8. Automatic stop fill valve (Jan. 1,1984 and on) 28 9-1 LPG WARNING AND FUEL ID LABELS 29 9-1 LPG WARNING AND FUEL ID LABELS 30 CHAPTER 8 ENGINE FUEL SYSTEMS D. 8-2.4 Carburetion equipment 8-2.4(b)4 Engine exhaust gas, heat for vaporizer 8-2.4(d) Automatic shut off valve or equivalent E. 8-2.5 Piping, hose and fittings 8-2.5(d)1. Hose, hose connections, and flexible connectors (stainless steel only) 8-2. 5(d)1.A. Hose markings 31 CHAPTER 8 ENGINE FUEL SYSTEMS F. 8-2.6 Installation of containers and container appurtenance 8-2.6(d) Container locations with respect to vehicle 8-2.6(i)1. to 4. Relief valve pipe away requirements 32 CHAPTER 8 ENGINE FUEL SYSTEMS G. 8-2.7 Containers mounted in the interior of vehicles 8-2 . 7(a)1. & 2. Gas-tight integrity 8-2.7(b) Permanently mounted remote fill H. 8-2.8 Pipe and hose installation 8-2.8(h) Hydrostatic relief valve requirements 33 CHAPTER 8 ENGINE FUEL SYSTEMS I. 8-2.9 Equipment installation 8-2.9(a) Manufacturer's recommendations J. 8-2.10 Marking (black diamond) K. 8-6(a)(b)(c) Garaging of vehicles, residential garages and sources of ignition 34 9-1 BLACK DIAMOND MARKING 35 PERSONAL LIABILITY • All combustible gases can be dangerous • Casual, careless handling is foolish • Installers are responsible for the work performed on and around the vehicle (and its fuel) • Responsible means liable, which includes law suits and personal loss • Best insurance policies are common sense, safe handling, and integrity of the fuel system and the installer MODULE 9: Safety and Regulations

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 9-1

REVIEW THE PROPERTIES OF LPG

• Made of propane, butane, and mixes of both • Added artificial smell • Harmful if inhaled in place of oxygen • Heavier than air- 1.5 specific gravity • Dispersable into air with wind or vent systems • Expands from liquid state to gaseous state with volume increase of 270x • Absorbs heat from air as it vaporizes • Lower exhaust emissions than gasoline

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 9-2

SAFETY PROCEDURES FOR INSTALLING AND SERVICING LPG EQUIPMENT

• Wear gloves during refueling • Causes asphyxiation in high concentrations • Vent facilities properly

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 9-3

SAFETY PROCEDURES FOR INSTALLING AND SERVICING LPG EQUIPMENT

Fuel Tanks: • Can explode under extreme conditions or faulty pressure relief systems • Withstand 1000 psi • Fill to only to 80% • Ruptures will probably be leaks vs. explosions • No ignition inside tank- no oxygen present inside • Made of carbon steel; very puncture resistant, adds to vehicle structural strength, crash worthy

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 9-4

SAFETY PROCEDURES FOR INSTALLING AND SERVICING LPG EQUIPMENT

Tank Storage: • Store empties in designated conspicuous, secured, isolated area • Area should be dry, cool, vented, fire resistant • Tanks with LPG should be stored away from combustibles • Separate and label empty & full tanks

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 9-5

SAFETY PROCEDURES FOR HANDLING PRESSURIZED GASES

• All employees will be trained in proper handling and operating procedures • NPGA national training program for handling, equipment, and appliances • Certified Employee Training Program (CERT)

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 9-6

FACILITY SAFETY MODIFICATIONS

• Potential hazards: – Fire – Explosion – Asphyxiation • Eliminate ignition sources from within 25’ of refueling sites • See NFPA #58 for LPG dispenser installation and operation • Check state and local codes

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 9-7

SAFETY NOTES AND WARNINGS

NOTICE

Appropriate service methods and proper repair procedures are required for safe, reliable operation of motor vehicles as well as the safety of the technicians performing maintenance procedures

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 9-8

DISCONNECT BATTERY

• Negative (-) first then positive (+) • When installing new equipment • When making electrical connections • When disconnecting electrical connections

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 9-9

PERSONAL SAFETY

• Set parking brake when vehicle is stopped • Use safety stands when working under vehicle • Keep clothing and oneself away from moving parts when the engine is running • Remove jewelry and loose clothing before working on vehicle • Always wear safety glasses for eye protection

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 9-10

PERSONAL SAFETY

• Do not lift or move tanks or other heavy objects alone – Use at least two people – Wear proper lifting support braces – Use lifting devices when available

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 9-11

WORKING ON AND OPERATING THE VEHICLE

• No smoking around vehicle • Avoid skin contact with hot metal parts (radiator, exhaust manifold, tail pipe, catalytic converter and muffler) • Operate the engine only in well-ventilated area • Cover all exposed openings when removing parts from vehicle with clean lint-free cloth or plastic

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 9-12

WORKING ON AND OPERATING THE VEHICLE

• Work on parts removed from vehicle on a covered, non-abrasive surface • Do not step on bumpers or fenders • Cover fenders, bed floor and exposed surfaces that may betouched during work on vehicle

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 9-13

WARNINGS

• Stop smoking, shut off engine when fueling or venting propane • Vent fuel only in well ventilated area. Consult local authorities for specific off-loading regulations • Do not attempt to remove or disassemble propane components while system is pressurized

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 9-14

WARNINGS

• Tanks may be installed with a quantity of fuel loaded. – Do not open valves until system is installed or valve ports are sealed • Do not use damaged or broken parts and components

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 9-15

JACKING OR LIFTING THE VEHICLE

• See OEM owner's manual for jacking information • DO shutoff all tank valves before lifting • DO NOT use propane gas components (tanks, tank brackets, covers, fuel lines) as lift or contact points

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 9-16

TOWING A CONVERTED VEHICLE

• Converted Vehicles OK to tow • DO shutoff all tank valves before lifting or towing • DO NOT attach tow bars, towing chains or safety chains to propane gas components (tanks, tank brackets, covers, fuel lines) • DO NOT allow tow bars, towing chains or safety chains to rest or rub against propane gas components • DO NOT tow vehicles equipped with a tank aft of the rear axle from the rear- tow from front

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 9-17

VEHICLES INVOLVED IN ACCIDENTS

• Damaged vehicles may have damage to LPG components • Inspect and certify components and system integrity before returning vehicle to service • Inspect and leak check tank

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 9-18

NFPA #58 HIGHLIGHTS

• Following highlights pertain to LPG motor fuel work • Minimal standards for general safety • May not supercede local, state, or federal regulations

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 9-19

CHAPTER 1 GENERAL PROVISIONS

A. 1-5 Qualification of personnel

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 9-20

CHAPTER 3-7 IGNITION CONTROL

A. 3-7.2 Electrical equipment B. 3-7.3 Other sources of ignition

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 9-21

CHAPTER 3-9 VEHICLE FUEL DISPENSER AND DISPENSING STATIONS

A. 3-9.3 General installation provisions B. 3-9.4 Installation of vehicle fuel dispensers

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 9-22

CHAPTER 3-10 FIRE PROTECTION

A. 3-10.2 General 1. 3-10.2.5 Fire extinguisher (#18) 2. 3-10.2.6 LPG fires shall not normally be extinguished until source of fuel is shut off 3. 3-10.2 .7 Emergency controls

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 9-23

CHAPTER 4 LPG LIQUID TRANSFER

A. 4-2.1.1 Transfer personnel shall be in attendance during the entire transfer operation B. 4-2.3 Arrangement and operation of transfer systems 1. 4-2.3.2 Sources of ignition shall be controlled 2. 4-2.3.2 (a) Internal combustion engines (15') 3. 4-2.3.2 (b) Smoking, open flames, electrical tools & lights (25')

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 9-24

CHAPTER 4 LPG LIQUID TRANSFER

B. 4-2.3 Arrangement and operation of transfer systems 4. 4-2.3.2 (6) Sources of ignition, pilot lights, burners, electric ignition devices 5. 4-4.3 Compliance with maximum permitted filling limit provisions

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 9-25

CHAPTER 8 ENGINE FUEL SYSTEMS

A. 8-1.4 Properly trained (and licensed, where required) B. 8-2 General purpose vehicle engines fueled by LPG 1. 8-2.2 Containers 2. 8-2.2(c) Container markings 3. 8-2.2(d)(e) Aggregate water capacity 4. 8-2.2(g) Container labeling

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 9-26

CHAPTER 8 ENGINE FUEL SYSTEMS

C. 8-2.3 Container appurtenances 1. 8-2.3(a)4&5 Internal or flush-type relief valve 2. 8-2.3(a)8. Automatic stop fill valve (Jan. 1,1984 and on)

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 9-27

9-1 LPG WARNING AND FUEL ID LABELS

Courtesy of NFPA

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9-1 LPG WARNING AND FUEL ID LABELS

Courtesy of NFPA

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CHAPTER 8 ENGINE FUEL SYSTEMS

D. 8-2.4 Carburetion equipment 8-2.4(b)4 Engine exhaust gas, heat for vaporizer 8-2.4(d) Automatic shut off valve or equivalent E. 8-2.5 Piping, hose and fittings 8-2.5(d)1. Hose, hose connections, and flexible connectors (stainless steel only) 8-2. 5(d)1.A. Hose markings

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 9-30

CHAPTER 8 ENGINE FUEL SYSTEMS

F. 8-2.6 Installation of containers and container appurtenance 8-2.6(d) Container locations with respect to vehicle 8-2.6(i)1. to 4. Relief valve pipe away requirements

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 9-31

CHAPTER 8 ENGINE FUEL SYSTEMS

G. 8-2.7 Containers mounted in the interior of vehicles 8-2 . 7(a)1. & 2. Gas-tight integrity 8-2.7(b) Permanently mounted remote fill H. 8-2.8 Pipe and hose installation 8-2.8(h) Hydrostatic relief valve requirements

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 9-32

CHAPTER 8 ENGINE FUEL SYSTEMS

I. 8-2.9 Equipment installation 8-2.9(a) Manufacturer's recommendations J. 8-2.10 Marking (black diamond) K. 8-6(a)(b)(c) Garaging of vehicles, residential garages and sources of ignition

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 9-33

9-1 BLACK DIAMOND MARKING

Courtesy of NFPA

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 9-34

PERSONAL LIABILITY

• All combustible gases can be dangerous • Casual, careless handling is foolish • Installers are responsible for the work performed on and around the vehicle (and its fuel) • Responsible means liable, which includes law suits and personal loss • Best insurance policies are common sense, safe handling, and integrity of the fuel system and the installer

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 9-35

MODULE 10: Vehicle Compatibility Analysis

State of Oklahoma College of the Desert West Virginia University

Liquefied Petroleum MODULE 10: VEHICLE COMPATIBILITY ANALYSIS Gas

CONTENTS

OBJECTIVES...... 10-i INSTRUCTOR NOTES ...... 10-ii VEHICLE PREPARATIONS NECESSARY PRIOR TO A CONVERSION...... 10-1 SELECTING A VEHICLE FOR CONVERSION...... 10-1 WHAT ABOUT THE MANUFACTURER’S WARRANTY?...... 10-2 GATHER VEHICLE INFORMATION...... 10-2 DEDICATED, BI-FUEL, AND DUAL-FUEL VEHICLES ...... 10-2 STANDARDS AND REGULATIONS ...... 10-3 CREATE A RECORDED HISTORY OF THE VEHICLE...... 10-3 CUSTOMER & CONTACT INFORMATION...... 10-3 PRIOR EMISSION RECORDS FOR THE VEHICLE...... 10-4 PRE-CONVERSION PROCEDURES...... 10-4 EVALUATE ENGINE CONDITION...... 10-4 TEST FOR VEHICLE PERFORMANCE...... 10-4 CHECK COMPRESSION...... 10-5 IGNITION SYSTEM INSPECTION...... 10-5 CHECK THE FLUIDS...... 10-10 CHECK FILTERS, HOSES AND ELECTRICAL CONNECTIONS...... 10-11 ELECTRONIC ENGINE CONTROLS...... 10-13 CHECK THE EXHAUST SYSTEM...... 10-14 SUMMARY ...... 10-15 MODULE REVIEW ITEMS ...... 10-17 MRI SCORING KEY ...... 10-19 ACTIVITY 10-1: VEHICLE INFORMATION REGISTRATION OVERHEAD TRANSPARENCY MASTERS

Liquefied Petroleum Gas Training Program

PAGE 10-i Liquefied Petroleum MODULE 10: VEHICLE COMPATIBILITY ANALYSIS Gas

OBJECTIVES

At the completion of this module, the technician will be able to: • Identify vehicle preparations necessary prior to a conversion. • Discuss the process of selecting a vehicle for conversion. • Discuss the differences between a dedicated vs. bi-fuel conversions. • Discuss driving needs: range, LPG fuel tank(s) storage capacity and/or payload/storage. • Discuss the importance of emission records for the vehicle. • Develop a preliminary checklist prior to a conversion. • Perform a pre-conversion check on a vehicle prior to conversion. • Discuss the standards and regulations associated with a LPG conversion.

Liquefied Petroleum Gas Training Program PAGE 10-ii Liquefied Petroleum MODULE 10: VEHICLE COMPATIBILITY ANALYSIS Gas

INSTRUCTOR NOTES

INSTRUCTOR MATERIALS/MEDIA NEEDED Overhead projector or LCD panel/projection equipment Master overhead transparencies or Microsoft PowerPoint 4.0 presentation file Mod10.ppt

Note: Slides correspond to text as indicated by icon

VCR with TV or projection unit

Laboratory Activities: Activity 10-1: Vehicle Information Registration

Note: Lab activities correspond to text as indicated by icon

STUDENT MATERIALS/MEDIA NEEDED Module 10: Vehicle Compatibility Analysis

OVERHEAD TRANSPARENCY MASTERS The printouts enclosed with this module are taken from the Microsoft PowerPoint 4.0 presentation file Mod10.ppt . Instructors planning to use overhead projectors should make transparencies from these printouts on a copier (or laser printer designed to safely print to acetate.

Note: Please review Module 25: Training of Trainers for more hints on instructional needs and strategies.

Liquefied Petroleum Gas Training Program PAGE 10-1 Liquefied Petroleum MODULE 10: VEHICLE COMPATIBILITY ANALYSIS Gas

An obvious starting point for converting a vehicle to LPG is to select Key Points & Notes the conversion system. Before ordering a system, it is necessary to gather some information about the vehicle you have selected for conversion. VEHICLE PREPARATIONS NECESSARY PRIOR TO A CONVERSION Before an engine is converted to run on propane, it should be carefully inspected. An engine that is not in good mechanical 10-2 condition cannot deliver satisfactory performance. Any subsequent problems or mechanical failures the engine experiences might be unjustly blamed on the conversion or on the propane fuel system itself. The minimum items that should be checked are shown in the pre- conversion check form, Table 10-A. Though checking each and every item described on Table 10-A may not be necessary on every conversion, keep in mind that checking the engine beforehand may avoid trouble later. The more thorough the inspection, the less likely problems are to appear later. If the engine is mechanically sound, you can be reasonably sure it will continue to perform well regardless of the fuel used. See Table 10-A for a sample of a data collection form. Additional information may be required by fleet policy or other regulation. Also refer to equipment manufacturers pre-conversion guidelines. Note: It is not uncommon that new vehicles have mechanical or electrical problems. For example, those that sit on dealer lots for long periods may develop “lot rot” or a tank of stale gasoline. SELECTING A VEHICLE FOR CONVERSION While nearly any vehicle can be converted to use LPG, not all vehicles are good choices for conversion. A measure of common 10-3 sense is needed in selecting a vehicle for conversion. Keeping in mind that a significant investment of both parts and labor will be necessary, inspect the vehicle selected for conversion as if you are buying a used car. Is it mechanically sound? Will it be able to handle the extra weight of fuel tanks? Is there adequate space for the fuel tanks and other system components? Changing fuel systems will not correct any existing mechanical problems the vehicle had before conversion! Decide if the vehicle type will make a good LPG conversion. Compacts and sub-compacts are least desirable for conversions when long driving ranges are expected because they lack sufficient space for fuel tanks. The age of the vehicle also should be considered. Newer vehicles with on-board computer diagnostic systems are much more efficient in controlling fuel delivery systems and reducing emissions. Typically, newer fuel injected vehicles have less power loss after conversion than do carburated vehicles using manifold heating. It is extremely important to analyze a potential conversion to ensure proper condition of the vehicle before proceeding. Generally, an acceptance test is applied to a vehicle that is a few years old or has 10-4

Liquefied Petroleum Gas Training Program PAGE 10-2 Liquefied Petroleum MODULE 10: VEHICLE COMPATIBILITY ANALYSIS Gas a high odometer reading. This test will aid in evaluating the status Key Points & Notes of the vehicle’s engine, compression ratio, fuel system, and ignition system. The results of this test will indicate if the vehicle is a good candidate for a LPG conversion. Acceptance measures commonly involve: • inspecting areas where tanks are to be mounted for possible weakening caused by rust and corrosion; • analyzing suspension potential for carrying increased loads resulting from on-board fuel tank(s); • performing a compression test to indicate if piston rings and valves are in acceptable condition; • checking the ignition system along with the starting circuit and the charging circuit to ensure proper operating condition; and • analyzing engine, horsepower, and emissions according to the manufacturer’s vehicle performance expectations. It is very important to verify the vehicle’s power output over its speed range before making a conversion. This measure will be used 10-5 as a baseline to indicate proper system installation and tuning. Excessive loss of power after a conversion may result from improper installation or tuning. Quality installation is imperative for insuring operating efficiency and safety. Poor installation of LPG system components is the number one cause of problems involving LPG vehicles.

WHAT ABOUT THE MANUFACTURER’S WARRANTY? It is important to find out if the vehicle’s manufacturer’s warranty will remain in effect. If a conversion damages another component, 10-6 the warranty may not apply. Contacting the manufacturer before a conversion may help confirm what components and policies can be affected if vehicle failure is caused by an LPG conversion. Generally, the OEMs will honor warranties if the conversion does not affect the integrity of the gasoline operation. However, unless the vehicle was converted and warranteed by the vehicle manufacture r, the supplemental LPG equipment will not be covered. For the reasons mentioned – and others – conversions are not done until the engine has broken in and run enough to assure that all OEM components are working well. Drive for a minimum of 200 miles to seat the piston rings and get the bugs out of electrical and mechanical systems.

GATHER VEHICLE INFORMATION Once a vehicle has been targeted for conversion, gather the following information: vehicle identification number (VIN), year, 10-7, 10-8 make, model, engine size and model, and carburetion or fuel injection. Some system manufacturers may need highly specific information such as: the carburetor manufacturer and model, throat diameter of the carburetor, and specifics of the fuel injection system (e.g., multiport or throttle body). It is also a good idea to test drive the vehicle before the conversion and see how it runs so that after the conversion is completed you will know what to expect.

Liquefied Petroleum Gas Training Program PAGE 10-3 Liquefied Petroleum MODULE 10: VEHICLE COMPATIBILITY ANALYSIS Gas

Write down notes about performance, idle, acceleration or any other Key Points & Notes characteristics of the vehicle. No t e : Some customers re q u i re recorded performance tests done before and after conversion with a dynamometer. DEDICATED, BI-FUEL, AND DUAL-FUEL VEHICLES There are two major types of conversions – dedicated and bi-fuel. A dedicated LPG vehicle uses only LPG as a motor fuel. Dedicated 10-9 propane powered vehicles are also known as straight or mono-fuel vehicles. Bi-fuel vehicles run on either one fuel or another, typically gasoline or propane; or gasoline or natural gas. Dual-fuel refers to an engine that runs on two fuels simultaneously, such as diesel and propane, or diesel and natural gas. These conversions are mostly made on compression ignition diesel engines, typically found in heavy-duty applications; and theref o r e not covered in this manual. These systems fall into three categories: fumigation, central point injection, and multi-point propane injection. STANDARDS AND REGULATIONS It is imperative that, as a technician, you have a good working knowledge of safety regulations and emission standards that 10-10 pertain to the installation of the propane fuel system components. In the United States, federal regulations within the Department of Transportation as well as state regulations apply to equipment and installation practices. In some instances, even local codes tell you what you can and can’t do. Special regulations may also apply to school buses, industrial trucks, and stationary engines. In Canada, a national installation code applies to all propane conversions. Most of these governmental bodies rely on the National Fire Protection Association (NFPA) Standard 58 for their basic safety rules, and those standards are followed in this manual. Be sure you know which rules apply to the vehicles you convert and that your work conforms to those standards. In the U.S., all states and most municipalities base their regulations on NFPA 58 in its capacity as an American National Standard. Some states supplement this standard, but rarely do they supersede it. Be sure that you are intimately familiar with the rules and regulations that apply to the equipment and vehicles which you are converting and that your work conforms to these requirements. CREATE A RECORDED HISTORY OF THE VEHICLE

CUSTOMER & CONTACT INFORMATION Fill out each block (refer to Table 10-A) as completely as possible to en s u r e that there are no future misunderstandings. The informa t i o n 10-11 blocks are as follows: Activity 10-1: Vehicle Shop Location: Name the conversion center. Information District: Note any applicable accounting code. Registration Customer: Enter the full name of the fleet or vehicle owner. Customer: Note any applicable customer identification code.

Liquefied Petroleum Gas Training Program PAGE 10-4 Liquefied Petroleum MODULE 10: VEHICLE COMPATIBILITY ANALYSIS Gas

Contact Name: Enter the name of person responsible for Key Points & Notes coordination of conversions. Phone: Phone number of contact. Fax: Fax number of contact. Address, City, State, & Zip: Enter the complete physical address of the customer for pickup and delivery.

PRIOR EMISSION RECORDS FOR THE VEHICLE If any emission records exist for the vehicle, retrieve the records to use for comparison data. Perform pre-conversion emission analysis if required.

PRE-CONVERSION PROCEDURES Enter all information as precisely as possible as this may be refered to in the future for a variety of reasons including but not limited to maintenance, equipment upgrades, problem disputes, and warranty information. Year: Enter the model year of the vehicle (not necessarily the production year). Make: Enter the OEM builder of the vehicle. Model: Enter the model designation of the vehicle. VIN: Enter the seventeen digit manufacturer’s identification code. Unit: The number or code the fleet uses to identify the vehicle, if applicable. Location: Where the fleet keeps the vehicle. Type: Check the block which best describes the type of vehicle or equipment configuration, or write in a better description.

EVALUATE ENGINE CONDITION Check the engine’s mileage or accumulated hours of running time. On most vehicles, the mileage can be determined by simply reading 10-12 the odometer. If the engine has been replaced or overhauled, figure only the mileage since then. On forklifts, industrial, off-road vehicles and stationary engines, use the engine hour meter as your guide. If an engine has more than 60,000 miles on it (or about 2,000 hours), it should receive an especially thorough pre-conversion inspection. Any questionable engine wear or damage should be repaired. All repairs, for example a valve job, should bring the engine up to unleaded fuel standards. Because propane is an unleaded fuel, the engine does not benefit from valve lubrication characteristics that leaded gasoline provides. All engines designed to operate on leaded fuel, which is no longer available in most areas, will eventually develop fuel-related problems, regardless of whether unleaded gasoline or propane is used. For this reason, all engines should be repaired appropriately. Finally, consider the type of use the engine has had during its life. Light-duty highway miles are not as hard on engines as short-trip, stop-and-go miles, or heavy-duty use.

Liquefied Petroleum Gas Training Program PAGE 10-5 Liquefied Petroleum MODULE 10: VEHICLE COMPATIBILITY ANALYSIS Gas

TEST FOR VEHICLE PERFORMANCE Key Points & Notes An experienced mechanic can often quickly judge an engine’s condition after observing how it runs and sounds. Start the engine 10-13 and note its behavior. Is it slow to start? Does it idle roughly or misfire? Does the engine make any unusual noises? Is there excessive smoke from the exhaust? Any of these conditions could indicate a problem. Take a test drive to determine the perfo r mance of the overall drive- train as well as steering, suspension, and brakes. If the vehicle does not perfo r m well on gasoline, it will not perfo r m well on propane. Any poor drivability conditions should be rec o r ded and brought to the attention of the customer prior to conversion. On computer control l e d vehicles, make sure the malfunction indicator light (MIL) comes on when the ignition is switched on — key on, engine off (KOEO).

CHECK COMPRESSION All spark plugs must be removed from the engine and the throttle opened to perform a proper compression test so all the cylinders 10-14 can be compared equally. Install a compression gauge into one of the spark plug holes and crank the engine an equal number of rotations (five to seven) for each cylinder. Note: a threaded, screw-in type compression tester is more reliable than the push-and-hold-in tester. Crank the engine with a remote starter switch or key, if you can disable the ignition. Repeat this test, recording the results for each cylinder. If the compression readings vary by more than 25 percent, perform a wet compression test. The wet test is a simple way to find out whether the piston rings or valves are the more likely source of your problem. Squirt a few shots of oil (one teaspoon or less) through the spark plug holes into the cylinders. The oil will coat the cylinder walls to compensate for piston ring wear. Prior to making the compression check, crank the engine a few seconds to help spread the oil. An increase in compression during a wet test indicates worn rings; no change in compression indicates valve/head wear. A very low compression reading in two adjacent cylinders is a typical symptom of a blown or leaking head gasket. A zero reading in a cylinder usually indicates a bad valve or damaged piston. Any of these conditions should be brought to the customer’s attention prior to conversion. Inspect the spark plugs before reinstalling them.

IGNITION SYSTEM INSPECTION The ignition system plays a key role in engine perf o rm a n c e reg a r dless of the type of fuel used. It must deliver sufficient firing 10-15 voltage at precisely the right instant to ignite the air-fuel mixture in the cylinders. Any weakness in the system that reduces the available firing voltage can cause hard starting and misfiring as well as reduced fuel economy and perfo r mance and increased emissions. Both electronic and point-type ignition systems can pro d u c e adequate voltage for propane ignition. But for peak voltage output,

Liquefied Petroleum Gas Training Program PAGE 10-6 Liquefied Petroleum MODULE 10: VEHICLE COMPATIBILITY ANALYSIS Gas all the ignition components, such as coil, cap and rotor, wires, Key Points & Notes plugs, condenser, points, pickup, and ignition module, must be in top condition. Adequate primary voltage is essential to ensure secondary output; a 1-volt drop in the primary voltage may result in a 5,000-volt drop in coil secondary voltage output. Refer to Figure 10-1. Any weaknesses or problems should be corrected beforehand because propane requires more firing voltage and increases the demands on the system. Therefore, a preliminary inspection of the ignition system should include the following.

Ignition Coil The ignition coil should be visually inspected for cracks or signs of arcing around the high voltage tower and primary terminals. Coil 10-17 output should be checked on the oscilloscope (minimum acceptable output should be within OEM specifications). If a scope is not available, check spark condition with a spark tester. If you suspect a weak coil, check the primary and secondary coil resistance with an ohmmeter. If it is not within OEM specifications, replace the coil. With E-core coils, check for signs of arcing between the laminated sections. Note: Do not connect any auxiliary devices, such as alternative fuel support modules, fuel lock, alarm, or hour meters to the power primary side of the ignition coil since it may result in a drop in secondary ignition voltage. Because propane has fewer carbon molecules than gasoline, it requires more voltage to ignite or ionize the combustible mixture. Therefore, more voltage is needed to fire the spark plugs. The three necessary ingredients of combustion are air, fuel, and heat. In a cylinder, the heat source is the spark from the spark plug.

10-16 8v

5ms 5ms 5ms 5ms 5ms 5ms 5ms 5ms 5ms Colin Messer 10 - 1 Se c o n d a r y ignition oscilloscope pattern, 1v = 1000v (normal gasoline engine patterns shown).

Liquefied Petroleum Gas Training Program PAGE 10-7 Liquefied Petroleum MODULE 10: VEHICLE COMPATIBILITY ANALYSIS Gas

Furthermore, a lean air-fuel mixture does not conduct electricity as Key Points & Notes well as a rich one, so more voltage is needed to jump the spark across the plug gap. Generally speaking, the plugs require a consistent minimum of 18,000 to 25,000 volts to ignite propane. By comparison, gasoline will fire with as little as 8,000 volts. NOTE: The ignition system should have ample reserve to supply adequate secondary ignition voltage. The open secondary ignition voltage should be 32,000 volts. Refer to Figure 10-1.

Spark Plugs The spark plugs should be removed and inspected. Plugs that have sharp, clean electrodes can be re-gapped and reused, as long as 10-18 they are of the proper heat range. However, visual inspection may not be sufficient. A new, healthy looking spark plug electrode may malfunction; therefore, a secondary ignition oscilloscope test should be performed. Selecting the correct spark plug heat range for the application is important because it affects engine performance. If a spark plug is too hot for the application, it can cause prei g n i t i o n , detonation, and decreased plug life. If the plug is too cold, it can quickly foul, causing misfire or incomplete combustion. A hotter plug has a longer heat path between the firing tip and cylinder head,

10-19

Short Path (Cold Plug) Long Path (Hot Plug) Courtesy of Champion Spark Plug Co. HOT PLUG COLD PLUG 10-20

Small Large insulator insulator base base absorbs absorbs little heat much heat

Insulator seal 49% of heat transfers to Insulator seal head gasket 42% of heat Heat transfer transfers at point threads Courtesy of IMPCO 10 - 2 Heat transfer paths differ for a hot and cold spark plug.

Liquefied Petroleum Gas Training Program PAGE 10-8 Liquefied Petroleum MODULE 10: VEHICLE COMPATIBILITY ANALYSIS Gas which dissipates combustion heat slower than a cold plug. Refer to Key Points & Notes Fi g u r e 10-2. A cold plug req u i r es more voltage to fire which puts an even grea t e r demand on the ignition system. The benefit of a cold plug is its ability to dissipate heat. When choosing a spark plug, determine the standard operating conditions of the vehicle. A standard heat range plug (OEM specified) performs best in light-duty or dual-fuel applications. For dedicated pr opane and heavy duty applications, a spark plug that is one or two he a t ranges colder than OEM specifications is recommended. Noble metal alloy and fine wire spark plugs conduct voltage well and provide long service. Split fire plugs should not be used as they put more metal into the combustion chamber, increasing chances of preigintion. Copper electrodes have wide heat ranges and good service life. Consult manufacturer literature for heat range and plug/engine specifications. Correct spark plug gap is also essential for proper combustion. Gap plugs on propane engines to tighter than OEM specifications. General recommendations are: a) On conventional point-type ignition, set gap to 0.027”. b) On electronic ignition (general applications), set gap to 0.035” or 0.020” less than OEM specifications, whichever is greater. c) On bi-fuel or emissions specific applications, set gap to OEM sp e c s .

Spark Plug Wires The plug wires should be visually inspected for cracks, broken insulation, or burns. The terminals should fit snugly into the 10-21 distributor cap and the boots should fit tightly around the spark plugs to keep out dirt, oil, and moisture. Check each plug wire’s resistance from end to end with an ohmmeter. If resistance exceeds factory specifications, install a new set of premium quality wires. Eight millimeter (8mm) silicone resistance type wires, found on most late-model high-voltage electronic ignition systems will provide better service with propane. Silicone resistance (premium) wires, tailored to fit the engine at hand, should be used in place of solid core wires. Silicone di-electric compound applied to plug, d i s t r i b u t o r, and coil terminal ends of each wire will re d u c e moisture, corrosion, and damage to plug wires when removed in the future.

Distributor Cap and Rotor The distributor cap and rotor should be removed and inspected closely for signs of wear, corrosion, cracking, or carbon tracking. If 10-22 any problems are found, a new premium quality cap or rotor or both should be installed. On point-type ignitions be sure to inspect point condition and gap. NOTE: Electronic pickup and capacitive discharge kits are available to upgrade point-type systems to electronic ignition.

Liquefied Petroleum Gas Training Program PAGE 10-9 Liquefied Petroleum MODULE 10: VEHICLE COMPATIBILITY ANALYSIS Gas

Firing Voltage and Pattern Key Points & Notes Observing ignition performance on an oscilloscope is the best way to detect ignition faults. The scope will identify common problems 10-23 such as inadequate firing voltage, excessive point resistance, fouled spark plugs, bad plug wires, etc.

o 50 10-25

40o LPG Curve

30o

Gasoline Curve 20o

10o

Courtesy of Autotronic Controls TDC 1000 2000 3000 4000 5000 6000 7000 Engine Speed (RPM) 10 - 3 Ignition advance curves for propane and gasoline.

Ignition Timing and Advance Check and record the ignition timing curve, including initial timing without vacuum advance, mechanical (centrifugal) timing without 10-24 vacuum advance, and the total timing with vacuum advance. Be sure to follow OEM manufacturer’s procedures for checking initial or base timing. Propane, having a higher octane level (105+), will tolerate a more aggressive initial increase in the advance curve than gasoline but will generally require a slightly lower total advance than gasoline. Refer to Figure 10-3. On non-computer controlled ignition advance mechanisms, timing curves of 10o initial, 28o mechanical, and 35o total (+ or -2o) are considered acceptable. However, modifications of these advance mechanisms may be considered tampering under emissions laws. For dedicated conversions on computer-controlled ignition advance systems, initial timing should be set to factory specifications; no other adjustments are necessary. Consult manufacture r ’ s procedure for timing adjustment.

Liquefied Petroleum Gas Training Program PAGE 10-10 Liquefied Petroleum MODULE 10: VEHICLE COMPATIBILITY ANALYSIS Gas

NOTE: Be sure that the timing advances smoothly from idle to Key Points & Notes total advance. Check this with a variable advance timing light. Propane, which has a higher octane rating than gasoline, burns slower than gasoline; therefore, ignition must start sooner to ensure complete combustion. Retarded timing may cause backfire s , incomplete combustion, and increased exhaust temperature s . Over-advancing the timing may cause autoignition and valve or piston damage as well as increased NOX emissions. NOTE: Many new engines have turbulent combustion chambers that burn the combustible charge rapidly. While modified timing advance may improve propane performance on some engines, it may not be necessary on engines with fast burning combustion chambers. Advanced timing may increase emissions and decrease performance.

CHECK THE FLUIDS Check Oil Level and Condition Verify that oil is SAE certified and of the proper grade and viscosity for the application. Refer to the OEM recommendation. For 10-26 dedicated-fuel applications, a gaseous fuel (LP-gas or natural gas) grade engine oil is recommended. This type of oil is available from most of the major oil companies and each has similar characteristics, most notably the absence of detergents and ash content: These are added to gasoline and diesel fuel oils to absorb and neutralize the acidity typically present from operation of liquid fuels. These ashes, composed of various products such as phosphorus, calcium, zinc, and others, can eventually solidify and coagulate in the oil in the absence of the acidity and form undesirable deposits in the engine. The gaseous fuels grade oils will eliminate this possibility and generally increase engine life and oil change intervals.

Check Coolant Level and Condition It is essential to the operation of the propane converter that the cooling system should be clean and functioning properly. The specific gravity should be within the range of protection for applicable operating temperatures. Cooling systems that show severe mineral build-up should be thoroughly flushed for efficient heat dissipation. NOTE: One-sixteenth of an inch of mineral scale has the insulating value of four inches of cast iron; scale reduces a cooling system’s ability to absorb engine heat. If scale build-up in the cooling passages is sufficient to seriously hamper cooling efficiency, a muriatic acid flush is recommended for the entire system. This procedure is difficult and hazardous and should be handled by an experienced cooling system technician. Finally, pressure test the system to check for leaks. Ethylene glycol antifreeze/coolant has a lower specific heat value than propylene glycol, which does not transfer heat well to the

Liquefied Petroleum Gas Training Program PAGE 10-11 Liquefied Petroleum MODULE 10: VEHICLE COMPATIBILITY ANALYSIS Gas converter vaporizer-regulator. (See Specific Heat in glossary.) A Key Points & Notes properly operating thermostat maintains optimal engine coolant temperature. Correct engine temperature information is essential for the PCM to manage the engine.

Check Transmission Fluid Level and Condition Transmission fluid level should be within OEM specifications and in good condition. Inspect fluid for discoloration, particulates, and bu r nt odor. If necessary, drain the fluid, replace the filter, and ref i l l with the appropriate type of fluid. While this has no direct bearing on engine perfo r mance, it is essential to maximize power and torqu e distribution as well as to assure customer satisfaction. Most modern PCMs integrate the engine and transmission controls together; th e re f o r e, it is possible that a transmission related problem may appear to be an engine prob l e m .

CHECK FILTERS, HOSES, AND ELECTRICAL CONNECTIONS Check condition of air filter, PCV-valve, crankcase vent filter, belts, hoses, and component brackets. Replace any of these accessories as 10-27 necessary. Check battery level and condition, wires, and terminals. Replenish electrolyte with distilled water and recharge as necessary. Inspect wires and terminal connectors as necessary. NO T E : Most starting and other “hard to solve” electrical prob l e m s may be caused by bad connections at the battery, voltage drops in the battery cables, or by poor small wire connections or grou n d s . Refer to Figure 10-4. Because electronic components use such small amounts of current (milliamps), connections starting at the battery all the way through the system must be clean and tight. En s u r e that all engine to chassis ground straps are intact and se c u re .

10-28

Courtesy of Oklahoma Dept. of Vocational & Technical Education 10-4 Poor wire connections.

Hoses Inspect the cooling system hoses for kinks, cracks, cuts, tears, and dry rot. This is a good time to determine the directions of flow through the hoses and thus where the best points of insertion for the “water Y” fittings. Replace any hoses that look or feel worn. Do not use inferior clamps; there will be more junctions in the system and it is desirable to minimize the chances for leaks.

Liquefied Petroleum Gas Training Program PAGE 10-12 Liquefied Petroleum MODULE 10: VEHICLE COMPATIBILITY ANALYSIS Gas

Filter Element Key Points & Notes It is advisable to replace all filters at this time, if practical. Otherwise, inspect all filters and replace as necessary.

Air Filter Inspect the air filter for debris and perforations of the filter element itself. Ensure that the rubber seal on the upper and lower surfaces of the element are in good condition and will provide an adequate seal and verify proper application for the element. Replace if necessary. The air filter is one of the components in the system that is taken least seriously. In fact, it is one of the more critical parts of the system. Airborne contamination is one of the leading causes of catastrophic engine failure. An undersized or over contaminated element will limit the engine’s performance and economy. Inferior quality elements frequently have fewer folds and less surface area in the element. Even though they may appear to have the same shape and size as the proper element, they may not have the same flow rating. If the engine is equipped with the OEM fresh air intake system, do not replace it unless the replacement is of similar design. Replace open “racing” style air cleaners with a fresh air system. Fresh, cool air is critical to engine performance. For every 10o F of increase in the temperature of intake air above 60o F, the engine looses one percent of its efficiency. For example, if underhood temperatures were 200o F (95o C), you could experience as much as a 14 percent drop in performance. Record the part number in the applicable block (Table 10-A).

Oil Filter If the oil inspection indicated the need for changing, be sure to change the oil filter. Dispose of the filter properly. Record the part number in the applicable block.

PCV Filter Inspect the crank case vent filter for dirt and excess oil residue. Replace if necessary. Record the part number in the applicable block. Note: If the original air filter assembly is replaced, ensure that the crankcase ventilation hose is routed to filtered air.

Belts Inspect the belts for cracks, dry rot, separation, and proper tension. Tighten or replace as necessary. Record the part number in the applicable block. Inspect serpentine belt tensioners for bearing noise, weak tension or misalignment.

Battery Inspect battery for charge, leaks, water level, and specific gravity. Inspect terminals, cables, battery box, and retaining fixtures for corrosion and secure attachment. Refer to Figure 10-5. Ensure that the battery has sufficient cold cranking amperage for the engine. Charge, water, or replace the battery as necessary. Clean, repair, or replace terminal fixtures and cables as necessary.

Liquefied Petroleum Gas Training Program PAGE 10-13 Liquefied Petroleum MODULE 10: VEHICLE COMPATIBILITY ANALYSIS Gas

NOTE: When the battery is disconnected, PCM Keep Alive Power Key Points & Notes is removed and all trouble codes and block learn memory are erased. Auxiliary Keep Alive Memory (KAM) Power adaptors are available. When disconnecting the battery, it is recommended that an alternative power supply be used to keep computer memory alive. This device, which uses a 9v battery, plugs into the cigarette lighter.

10-29

Courtesy of Oklahoma Dept. of Vocational & Technical Education 10-5 Common battery problems.

ELECTRONIC ENGINE CONTROLS Applicable emissions and electronic engine controls must function correctly. This includes, but is not limited to, the following fuel and emission control components: the air pump, EGR, EFE, EVAP, HEGO, and PCV.

Emissions Equipment Using an emissions component standards guide, locate and inspect each required component. Ensure that each one is present and 10-30 operational. These include, but are not limited to: PCV: Inspect the positive crankcase ventilation valve and hose for good seals and wear. Remove the PCV and shake it to ensure that the valve seat is not stuck. Run the RPM up and verify that the valve has flow. Replace hose or valve if necessary. Indicate status in appropriate block. EGR: Check the exhaust gas recirculation valve for secure mount. Inspect vacuum tubing and control valve for cracks, dry rot, and good terminal connections. Under no circumstances should the EGR valve be blocked off or the control valve disabled. Indicate the status of the component in the applicable block. Perform an EGR test following OEM procedures. AIR: Inspect the air injection reaction pump or “smog pump,” if so equipped, to ensure that the pulley is spinning freely and that

Liquefied Petroleum Gas Training Program PAGE 10-14 Liquefied Petroleum MODULE 10: VEHICLE COMPATIBILITY ANALYSIS Gas

the belt is free of cracks, dry rot, and separation. Adjust belt Key Points & Notes tension if necessary. Inspect the hoses for secure clamping, kinks, or dry rot and verify proper routing. Check diverter valve operation and vacuum tubing, control valves, and terminals. Verify pump, diverter valves, and control valve operation. Under no circumstances should the pump or related components be removed or rendered inoperative. Indicate the status of the component in the applicable block. CANP: Inspect the canister purge charcoal reservoir for secure mount and tubing connections. Inspect all tubing for cracks, kinks, dry rot, and proper routing. If the charcoal canister appears to have been saturated with gasoline liquid, it can become deactivated and should be replaced. Inspect purge control valve, wiring, and terminals for good connections and operation. Replace any dysfunctional components as necessary. Indicate the status of the component in the applicable block. On mono-fuel dedicated vehicles the CANP may be removed if the gasoline tank has been removed. However, this is done if the modification is permitted by emissions regulations. EFE: Inspect early fuel evaporation system, if so equipped, by applying vacuum to the baffle control dashpot and verifying that it opens. Inspect the hose from the exhaust manifold and all related vacuum tubing for secure connections. Replace any tubing, hose, or components as required. Indicate the status of the component in the applicable block. CAT: Locate and verify that all required catalytic converters or thermal reactors are present and operational. Inspect each unit housing for evidence of heat damage, impact, or leaks. Check for cracks on welds or tightness of clamps where the unit is mounted to pipes. Replace components if necessary with a legal, OEM equivalent unit. Indicate the status of the component in the applicable block. Generally, if CAT back pressure is > 1.0 psig, the catalytic converter should be replaced.

O2S: Locate all oxygen sensors and check for secure installation, exhaust leaks, wiring, and terminal connections. Allow the engine to run until operating temperature is attained. Test sensors following OEM procedures. NOTE: False trouble codes may have been logged during the test 10-31 procedure and will have to be cleared after completion of the p re-conversion pro c e d u re s . Repair or replace sensors or connectors as necessary. Indicate the status of the component in the applicable block. DTC (Diagnostic T rouble Codes): Peter Aschwanden Perform a self-diagnostic test on the PCM using a scan tool and 10 - 6 Test PCM with scan tool.

Liquefied Petroleum Gas Training Program PAGE 10-15 Liquefied Petroleum MODULE 10: VEHICLE COMPATIBILITY ANALYSIS Gas

OEM diagnostic procedures. Record all trouble codes found in Key Points & Notes the applicable space on the form. Refer to technical manuals for diagnostic procedures. Run test and repair procedures on each code, starting with the lowest code number and working up through the remaining higher codes. Clear all codes after repairs are completed following the OEM instructions. Note: It is extremely important, especially on OBD II vehicles, to not simply clear codes but fix the cause of the code first.

CHECK THE EXHAUST SYSTEM Examine the entire exhaust system for leaks, connections, and mounting. Check the muffler and catalyst for proper operation. If 10-32 the catalyst rattles or appears to have structural or high- t e m p e r a t u re damage (discoloration, dents, cracks, or holes), perform a back-pressure test. This is easily done by removing the oxygen sensor and replacing it with a threaded fitting attached to a positive pressure gauge. High converter pressures will greatly reduce engine performance on any fuel. Run the engine under load at 2500 RPM while reading the gauge. It should not exceed manufacturer’s specifications.

SUMMARY All repairs or omissions of repairs requested by the customer should be noted on the pre-conversion check form along with other 10-33 comments and recommendations. They should be rated “Pass” or “Fail” as determined by the technician, then signed by both the technician and the customer. Strict adherence to, and documentation of, pre-conversion check procedures are essential for quality conversion, which will lead to good customer relations and protect technician liability and industry reputation.

Liquefied Petroleum Gas Training Program PAGE 10-16 Liquefied Petroleum MODULE 10: VEHICLE COMPATIBILITY ANALYSIS Gas

VEHICLE CONVERSION CHECK FORM FOR PRE-CONVERSION & POST-CONVERSION INSPECTIONS

SHOP LOCATION: DISTRICT NO:

CUSTOMER: CUSTOMER NO:

CONTACT NAME: PHONE FAX:

ADDRESS:

CITY: STATE: ZIP:

PRE-CONVERSION PROCEDURES YEAR: MAKE: MODEL: VIN:

MILES: UNIT NO: LOCATION: 5 8 10

TYPE: BUS VAN CAR P/U F/L GEN

COMPRESSION: 1 2 3 4 5 6 7 8

IGNITION: COIL: PLUGS: GAP: WIRES: CAP: ROTOR:

FLUIDS: COOLANT: TRANS: OIL: HOSES: FILTERS:AIR-OIL PCV:

BELTS: BATTERIES: EXHAUST:PIPE MUFFLER: BRACKET: GASKET

EMISSIONS: PCV EGR AIR CANP EFE CAT EGO IS WORKING IS DISABLED IS MISSING ECM TROUBLE CODES:

COMMENTS:

Table 10-A Pre-Conversion Check Form

Liquefied Petroleum Gas Training Program PAGE 10-17 Liquefied Petroleum MODULE 10: VEHICLE COMPATIBILITY ANALYSIS Gas

MODULE REVIEW ITEMS

Note to Technician: Consider all choices carefully and select the best answer to each. 1. What procedures should be followed prior to a conversion? A. Make sure the engine is in proper mechanical condition. B. Replace the engine if necessary. C. Repair all needed problems. D. A & C.

2. What are important factors to consider when evaluating a vehicle for conversion? A. Geographic location. B. Type of use (i.e., light-duty). C. Who will be driving the vehicle. D. None of the above.

3. Although nearly any vehicle can be converted to use LPG, not all are good choices for conversion. A. True. B. False.

4. What should be evaluated when test driving a vehicle prior to conversion? A. How the engine runs and sounds. B. How the engine starts. C. Any excessive exhaust smoke. D. All of the above.

5. Prior to conversion, verify that the vehicle will be able to handle extra _____ of the fuel tanks. A. Size. B. Pressure. C. Weight. D. A & C.

6. Changing the fuel system of a vehicle will not correct any existing mechanical problems it had prior to conversion. A. True. B. False.

7. Which of the following refers to an engine that runs on two fuels simultaneously? A. Dual-fuel. B. Bi-fuel. C. Dedicated fuel. D. Di-fuel.

8. When would an acceptance test be applied to a vehicle that is being considered for conversion? A. When the vehicle is older. B. When the vehicle has a high odometer reading. C. A & B. D. None of the above.

Liquefied Petroleum Gas Training Program PAGE 10-18 Liquefied Petroleum MODULE 10: VEHICLE COMPATIBILITY ANALYSIS Gas

9. What do acceptance measures commonly involve? A. Inspecting tank areas for rust. B. Analyzing suspension potential. C. Performing a compression test. D. All of the above.

10. Why is it important to record the vehicle’s power output over its speed range prior to conversion? A. To ensure proper installation. B. To establish a baseline. C. To ensure proper tuning. D. All of the above.

11. What might excessive power loss after a conversion result from? A. Faulty electrical system. B. Faulty ignition system. C. Improper installation or tuning. D. None of the above.

12. What is the main cause of problems involving LPG vehicles after conversion? A. Poor quality components. B. Poor installation. C. Poor tuning. D. Poor emissions.

13. It is not important to find out if the vehicle manufacturer’s warranty will remain in effect. A. True. B. False.

14. Once a vehicle has been targeted for conversion, gather all of the following except: A. VIN. B. Engine size. C. Date of last oil change. D. Make and model.

Liquefied Petroleum Gas Training Program PAGE 10-19 Liquefied Petroleum MODULE 10: VEHICLE COMPATIBILITY ANALYSIS Gas

MRI SCORING KEY

1. D 2. B 3. A 4. D 5. D 6. A 7. A 8. C 9. D 10. D 11. C 12. B 13. B 14. C

Liquefied Petroleum Gas Training Program

Liquefied Petroleum MODULE 10: VEHICLE COMPATIBILITY ANALYSIS Gas

ACTIVITY 10-1: VEHICLE INFORMATION REGISTRATION

OBJECTIVE

To gain exposure to a vehicle inspection report. To begin entering vehicle information into the inspection report.

MATERIALS NEEDED

Vehicle inspection report form

METHOD

Observe the inspection report and what information it calls for. Enter the relevant information prior to your conversion and store the form where instructed. You will be using it later for the post-conversion inspection.

QUESTIONS

Are you familiar with the abbreviations used on the form? If not, ask the instructor for clarification.

Liquefied Petroleum Gas Training Program

1 MODULE 10: Vehicle Compatibility Analysis 2 VEHICLE PREPARATIONS NECESSARY PRIOR TO A CONVERSION • Careful engine inspection • Pre-conversion check form, Table 10-A • OEM pre-conversion guidelines • New vehicles may have problems too 3 SELECTING A VEHICLE FOR CONVERSION • Is it mechanically sound? • Will it handle the extra weight of fuel tanks? • Is there adequate space for fuel tanks and other components? • What are the driving ranges expected? • How old is the vehicle? 4 SELECTING A VEHICLE FOR CONVERSION Acceptance testing for: – Tank mounting area – Suspension for added weight – Compression test on piston rings and valves – Ignition, starting, and charging systems – Engine, horsepower, emissions 5 SELECTING A VEHICLE FOR CONVERSION • Baseline power output over speed range • Reference for proper system installation and tuning 6 MANUFACTURER’S WARRANTY • Will conversion affect warranty? • Check with all OEMs • Break-in period for engine 7 GATHER VEHICLE INFORMATION • Vehicle ID number • Year • Make • Model • Engine size and model • Carburetion or fuel injection 8 GATHER VEHICLE INFORMATION Include specific information if available: – Carburetor mfg and model – Throat diameter of carburetor – Multiport or throttle body fuel injector – Emissions data

Test drive the vehicle before conversion: – Note how it runs, idles, accelerates, etc. 9 DEDICATED, BI-FUEL, AND DUAL-FUEL VEHICLES • Dedicated – Straight or mono-fuel vehicles • Bi-Fuel – Runs on either one fuel or another • Gasoline or propane • Dual-Fuel – Runs on two fuels simultaneously • Diesel and propane 10 STANDARDS AND REGULATIONS • Safety regulations • Emission standards • Federal regulations – DOT • State regulations • National Fire Protection Association (NFPA) 11 CREATE A RECORDED HISTORY OF THE VEHICLE • Customer & Contact Information • Prior Emission Records for the Vehicle • Pre-Conversion Procedures 12 EVALUATE ENGINE CONDITION • Thorough engine inspection • Miles or hours of engine operation • Repairs or replacement • Type of engine use 13 TEST FOR VEHICLE PERFORMANCE Engine Performance: – Behavior – Operation – Sounds Other Vehicle Systems: – Steering – Suspension – Brakes 14 CHECK COMPRESSION • Remove all spark plugs • Open throttle • Install a compression gauge 15 IGNITION SYSTEM INSPECTION • Delivers firing voltage at precise time to ignite mixture • Electronic and point type systems • Voltage drops 16 10-1 SECONDARY VOLTAGE OUTPUT 17 IGNITION COIL • Test with scope or spark tester • LPG needs 18KV - 25KV to ignite • Gasoline needs 8KV 18 SPARK PLUGS • Remove and inspect • Correct spark plug heat range • Hot/cold plugs • Standard operating condition of vehicle • Gap width 19 10-2A HEAT TRANSFER PATHS 20 10-2B HEAT TRANSFER PATHS 21 SPARK PLUG WIRES • Inspect wires, terminals, and boots • Resistance • Silicone resistance type wires 22 DISTRIBUTOR CAP AND ROTOR • Inspect and replace as necessary 23 FIRING VOLTAGE AND PATTERN • Use oscilloscope to detect problems 24 IGNITION TIMING AND ADVANCE • Check and record timing – Initial timing w/o vacuum advance – Mechanical timing w/o vacuum advance – Total timing with vacuum advance • Timing curves of 10o initial, 28o mechanical, and 35o total (+ or -2o) acceptable • LPG burns slower so ignition must start sooner • New engines with turbulent combustion chambers 25 10-3 IGNITION ADVANCE CURVES 26 CHECK THE FLUIDS • Check oil level and condition • Check coolant level and condition • Check transmission fluid level and condition 27 CHECK FILTERS, HOSES AND ELECTRICAL CONNECTIONS • Hoses • Air filter • Oil filter • PCV filter • Belts • Battery 28 10-4 POOR WIRE CONNECTIONS 29 10-5 BATTERY PROBLEMS 30 ELECTRONIC ENGINE CONTROLS Emissions Equipment – PCV – EGR – AIR – CANP – EFE – CAT

–O2S – DTC 31 10-6 TEST PCM WITH SCAN TOOL 32 CHECK THE EXHAUST SYSTEM • Look for leaks, connections, mountings • Muffler, catalyst operation – Back-pressure test 33 SUMMARY • Note customer repairs • “Pass”/”Fail” • Quality inspection = quality conversion

MODULE 10: Vehicle Compatibility Analysis

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 10-1

VEHICLE PREPARATIONS NECESSARY PRIOR TO A CONVERSION

• Careful engine inspection • Pre-conversion check form, Table 10-A • OEM pre-conversion guidelines • New vehicles may have problems too

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 10-2

SELECTING A VEHICLE FOR CONVERSION

• Is it mechanically sound? • Will it handle the extra weight of fuel tanks? • Is there adequate space for fuel tanks and other components? • What are the driving ranges expected? • How old is the vehicle?

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 10-3

SELECTING A VEHICLE FOR CONVERSION

Acceptance testing for: – Tank mounting area – Suspension for added weight – Compression test on piston rings and valves – Ignition, starting, and charging systems – Engine, horsepower, emissions

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 10-4

SELECTING A VEHICLE FOR CONVERSION

• Baseline power output over speed range • Reference for proper system installation and tuning

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 10-5

MANUFACTURER’S WARRANTY

• Will conversion affect warranty? • Check with all OEMs • Break-in period for engine

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 10-6

GATHER VEHICLE INFORMATION

• Vehicle ID number • Year • Make • Model • Engine size and model • Carburetion or fuel injection

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 10-7

GATHER VEHICLE INFORMATION

Include specific information if available: – Carburetor mfg and model – Throat diameter of carburetor – Multiport or throttle body fuel injector – Emissions data

Test drive the vehicle before conversion: – Note how it runs, idles, accelerates, etc.

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 10-8

DEDICATED, BI-FUEL, AND DUAL-FUEL VEHICLES

• Dedicated – Straight or mono-fuel vehicles • Bi-Fuel – Runs on either one fuel or another • Gasoline or propane • Dual-Fuel – Runs on two fuels simultaneously • Diesel and propane

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 10-9

STANDARDS AND REGULATIONS

• Safety regulations • Emission standards • Federal regulations – DOT • State regulations • National Fire Protection Association (NFPA)

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 10-10

CREATE A RECORDED HISTORY OF THE VEHICLE

• Customer & Contact Information • Prior Emission Records for the Vehicle • Pre-Conversion Procedures

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 10-11

EVALUATE ENGINE CONDITION

• Thorough engine inspection • Miles or hours of engine operation • Repairs or replacement • Type of engine use

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 10-12

TEST FOR VEHICLE PERFORMANCE

Engine Performance: – Behavior – Operation – Sounds Other Vehicle Systems: – Steering – Suspension – Brakes

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 10-13

CHECK COMPRESSION

• Remove all spark plugs • Open throttle • Install a compression gauge

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 10-14

IGNITION SYSTEM INSPECTION

• Delivers firing voltage at precise time to ignite mixture • Electronic and point type systems • Voltage drops

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 10-15

10-1 SECONDARY VOLTAGE OUTPUT

Secondary ignition oscilloscope pattern, 1v = 1000v (normal gasoline engine patterns shown)

5ms 5ms 5ms 5ms 5ms 5ms 5ms 5ms

Colin Messer

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 10-16

IGNITION COIL

• Test with scope or spark tester • LPG needs 18KV - 25KV to ignite • Gasoline needs 8KV

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 10-17

SPARK PLUGS

• Remove and inspect • Correct spark plug heat range • Hot/cold plugs • Standard operating condition of vehicle • Gap width

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 10-18

10-2A HEAT TRANSFER PATHS

Short Path (Cold Plug) Long Path (Hot Plug)

Courtesy of Champion Spark Plug Co.

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 10-19

10-2B HEAT TRANSFER PATHS

COLD PLUG HOT PLUG

Small insulator Large insulator base absorbs base absorbs little heat much heat

Insulator seal

49% of heat transfers to Insulator seal head gasket Heat transfer 42% of heat point transfers at threads

Courtesy of IMPCO

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 10-20

SPARK PLUG WIRES

• Inspect wires, terminals, and boots • Resistance • Silicone resistance type wires

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 10-21

DISTRIBUTOR CAP AND ROTOR

• Inspect and replace as necessary

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 10-22

FIRING VOLTAGE AND PATTERN

• Use oscilloscope to detect problems

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 10-23

IGNITION TIMING AND ADVANCE

• Check and record timing – Initial timing w/o vacuum advance – Mechanical timing w/o vacuum advance – Total timing with vacuum advance • Timing curves of 10o initial, 28o mechanical, and 35o total (+ or -2o) acceptable • LPG burns slower so ignition must start sooner • New engines with turbulent combustion chambers

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 10-24

10-3 IGNITION ADVANCE CURVES

Courtesy Autotronic Controls College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 10-25

CHECK THE FLUIDS

• Check oil level and condition • Check coolant level and condition • Check transmission fluid level and condition

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 10-26

CHECK FILTERS, HOSES AND ELECTRICAL CONNECTIONS

• Hoses • Air filter • Oil filter • PCV filter • Belts • Battery

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 10-27

10-4 POOR WIRE CONNECTIONS

Courtesy of Oklahoma Dept. of Vocational & Technical Education

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 10-28

10-5 BATTERY PROBLEMS

Courtesy of Oklahoma Dept. of Vocational & Technical Education

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 10-29

ELECTRONIC ENGINE CONTROLS

Emissions Equipment – PCV – EGR – AIR – CANP – EFE – CAT

–O2S – DTC

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 10-30

10-6 TEST PCM WITH SCAN TOOL

Peter Aschwanden

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 10-31

CHECK THE EXHAUST SYSTEM

• Look for leaks, connections, mountings • Muffler, catalyst operation – Back-pressure test

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 10-32

SUMMARY

• Note customer repairs • “Pass”/”Fail” • Quality inspection = quality conversion

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 10-33

MODULE 11: Equipment Layout & Design

State of Oklahoma College of the Desert West Virginia University

Liquefied Petroleum MODULE 11: EQUIPMENT LAYOUT & DESIGN Gas

CONTENTS

OBJECTIVES...... 11-i INSTRUCTOR NOTES ...... 11-ii PRELIMINARY CONSIDERATIONS FOR SELECTING CONVERSION EQUIPMENT ...... 11-1 CONVERSION SYSTEM COMPANIES AND SUPPLIERS...... 11-1 SYSTEM SPECIFICATIONS, COST, VAAILABILITY, AND WARRANTIES...... 11-1 DRAW SCHEMATIC OF VEHICLE LAYOUT ...... 11-1 COMPONENT TO COMPONENT CHECKLIST ...... 11-1 MEASURE VEHICLE AND SIZE COMPONENTS FOR CONVERSION ...... 11-3 SAFETY GUIDELINES...... 11-3 EXHAUST REROUTING ...... 11-3 HEAT SHIELDING ...... 11-3 VAPOR TIGHT COMPARTMENT...... 11-3 EQUIPMENT PROTECTION...... 11-3 COSMETICS ...... 11-4 COMPARTMENT...... 11-4 MODULE REVIEW ITEMS...... 11-7 MRI SCORING KEY...... 11-9 OVERHEAD TRANSPARENCY MASTERS

Liquefied Petroleum Gas Training Program

PAGE 11-i Liquefied Petroleum MODULE 11: EQUIPMENT LAYOUT & DESIGN Gas

OBJECTIVES

At the completion of this module, the technician will be able to: • Describe and evaluate the considerations for selecting a conversion system. • Measure the vehicle, and size and number the components for the conversion. • Draw and interpret a schematic of the conversion. • Identify the tasks and duties for beginning the conversion. • Identify specific layout considerations and modify vehicle systems required for a conversion if necessary. • Be familiar with and discuss the NFPA 58 regulations concerning layout, design, and modifications.

Liquefied Petroleum Gas Training Program PAGE 11-ii Liquefied Petroleum MODULE 11: EQUIPMENT LAYOUT & DESIGN Gas

INSTRUCTOR NOTES

INSTRUCTOR MATERIALS/MEDIA NEEDED Overhead projector or LCD panel/projection equipment Overhead transparency masters or Microsoft PowerPoint 4.0 presentation file Mod11.ppt

Note: Slides correspond to text as indicated by icon VCR with TV or projection unit

STUDENT MATERIALS/MEDIA NEEDED Module 11: Equipment Layout & Design

OVERHEAD TRANSPARENCY MASTERS The printouts enclosed with this module are taken from the Microsoft PowerPoint 4.0 presentation file Mod11.ppt . Instructors planning to use overhead projectors should make transparencies from these printouts on a copier (or laser printer designed to safely print to acetate.

Note: Please review Module 25: Training of Trainers for more hints on instructional needs and strategies.

Liquefied Petroleum Gas Training Program PAGE 11-1 Liquefied Petroleum MODULE 11: EQUIPMENT LAYOUT & DESIGN Gas

PRELIMINARY CONSIDERATIONS FOR SELECTING Key Points & Notes CONVERSION EQUIPMENT Before selling an installer a system, some manufacturers require that the technician attend their specialized training. The 11-2 complexities of some systems justify the extra training needed to become a proficient technician.

CONVERSION SYSTEM COMPANIES AND SUPPLIERS There are many conversion system manufacturers, and the options that may be available with certain systems vary. Investigate the 11-3 needs of the customer before ordering the system, because the manufacturer may not offer the specific options required. Also, emissions regulations stipulate that for a system to be legally installed on a vehicle, it must be certified for the engine in that vehicle. It is essential that the conversion system be designed for the specific engine.

SYSTEM SPECIFICATIONS, COST, AVAILABILITY, AND WARRANTIES Much like other purchases, shopping around for LPG conversion systems can pay off. Be aware that the conversion time is a major 11-4 factor in calculating the total cost of a LPG conversion. Certain systems may be less expensive, but the increased installation time may offset these savings. Experience is the best guide in selecting a system. Contact the conversion system manufacturer for specific answers to questions that may arise. Availability of a system for the specific vehicle and the parts, if replacement is ever needed, should be a consideration. Warranty coverage is changing; it has traditionally been one-year parts or labor or both with optional extended warranties of 3-5 years. New EPA regulations specify that the conversion emission warranty must be comparable to existing gasoline OEM warranties. Ultimately, these warranty options will be reflected in the price of the conversion system. Conversion equipment is best evaluated on merit and not solely on price. Consider technician labor to install, adjust and maintain the system. DRAW SCHEMATIC OF VEHICLE LAYOUT Use a template or sketch to draw locations of components. Write in dimensions and component names. or specific locations if 11-5 necessary. Attach smaller sketches of brackets and keep for the vehicle record. When performing the conversion, an accurate, well- designed plan is essential. Refer to Figures 11-1 and 11-2. COMPONENT-TO-COMPONENT CHECKLIST Again, refer to your system manual. Different systems have different components. Two or more components may be combined 11-8 into a single component, eliminating the need for hoses. Some components may be arranged in different orders. A general checklist of hose requirements and locations can include the following: • fuel tank relief valve vent hose;

Liquefied Petroleum Gas Training Program PAGE 11-2 Liquefied Petroleum MODULE 11: EQUIPMENT LAYOUT & DESIGN Gas

Key Points & Notes

11-6

West Virginia University 11-1 Typical LPG installation diagram.

11-7

11-2 Proposed conversion layout (truck shown).

Liquefied Petroleum Gas Training Program PAGE 11-3 Liquefied Petroleum MODULE 11: EQUIPMENT LAYOUT & DESIGN Gas

• fuel tank lockoff valve to hydrostatic relief valve; Key Points & Notes • hydrostatic relief valve to automatic lockoff; • automatic lockoff to fuel filter; • fuel filter to regulator; • regulator to vaporizer; and • vaporizer to carburetor/spray bar. Be sure to use the appropriate hose between each component. MEASURE VEHICLE AND SIZE COMPONENTS FOR CONVERSION See Table 11-A of components, part numbers, and vendors. A similar table may be used to track ordering information for conversion 11-9 equipment. The form can later be used as part of the vehicle‘s rec o rd . SAFETY GUIDELINES Consult local authorities of jurisdiction before proceeding with conversion. See NFPA 58, local regulations, and Module 9. 11-10 EXHAUST REROUTING To install a fuel tank, it may be necessary to cut, move, and reposition the exhaust system components. DO NOT under any 11-11 circumstances move the catalytic converter. Be sure to properly shield the tank and route the fuel supply line well away from the exhaust (8” minimum). If repositioned, the exhaust system should be securely mounted and insulated and the exhaust flow should not be restricted. Proper bending equipment is essential to bend exhaust pipe. Ensure that the system will be leak and rattle free. HEAT SHIELDING Shielding material is usually made of bent steel or aluminum sheet. The installation and mounting of the shield should be secure so it 11-12 won’t rattle or fall off and cause serious damage. When inserting mounting brackets and fasteners, do not damage wires, hoses, or cables while drilling into the body of the vehicle. NOTE: Refer to Module 9, NFPA 58, and local regulations for protecting fuel tank(s) and supply line. VAPOR TIGHT COMPARTMENT NFPA 58 outlines correct, safe installation guidelines to ensure that the tank(s), valves, and fittings are sealed from the passenger 11-13 compartment. This is done by completely insulating the trunk or compartment in which the tank is mounted or enclosing the valves with a sealed, tight, vented cover. Refer to Figure 11-3. EQUIPMENT PROTECTION Depending on local regulations or customer specifications, it may be necessary to build and install shields or heavy protection around 11-16 regulators or tanks. Major concerns are heat, road debris and obstacles, as well as collision. Passenger vehicles such as school

Liquefied Petroleum Gas Training Program PAGE 11-4 Liquefied Petroleum MODULE 11: EQUIPMENT LAYOUT & DESIGN Gas buses may require specially rated components that are installed Key Points & Notes under strict safety guidelines. COSMETICS Tanks installed in trunks, pickup beds, or van interiors may need to be covered by plywood or steel and possibly carpeted. Cosmetic 11-17 modifications or improvements are usually performed after the conversion is complete or done by one member of the production team while other work on the vehicle is in progress. Be sure to consult the customer regarding space that may be lost or gained by the modifications. Consider safety requirements such as access to tank valves and fittings as well as excess weight.

COMPARTMENT A clean, transparent installation usually re q u i res at least a minimum of cosmetic work. In a trunk installation, for example, a 11-18 box may be carpeted or painted. In pickup installations, the tank may be covered with a tool box or rack. Consider access to tank valves and fittings when planning modification. Maintain OEM equipment such as carpeting and flooring whenever possible. Fit carpet or floor covering around the tank supports, fuel lines, and such to blend the conversion and preserve the integrity of the vehicle. It may be de-converted before the end of its useful life.

11-15

11-14

Photo © Harris Fogel 11-3 Tank in trunk of passenger car with seal shell (vapor box) cover removed. Inset Cover in place.

Liquefied Petroleum Gas Training Program PAGE 11-5 Liquefied Petroleum MODULE 11: EQUIPMENT LAYOUT & DESIGN Gas

YEAR/VEHICLE VIN AGENCY LPG COMPONENTS VENDOR PHONE DATE ORD’D BY WHOM DATE REC’D COMMENTS KIT TYPE

P/N CONVERTER

P/N LOCKOFF(S)

ELECTRIC P/N

VACUUM P/N MIXER

P/N AIR FILTER ASSEMBLY

P/N TANK(S)

SIZE(S)

BRACKET(S)

SIZE(S) HYDROSTAT

P/N

Table 11-A Component checklist

Liquefied Petroleum Gas Training Program PAGE 11-6 Liquefied Petroleum MODULE 11: EQUIPMENT LAYOUT & DESIGN Gas

LPG COMPONENTS VENDOR PHONE DATE ORD’D BY WHOM DATE REC’D COMMENTS HOSE(S) FUEL SIZE/LENGTH

WATER SIZE/LENGTH

VAPOR HOSE

SIZE/LENGTH

FITTINGS

REMOTE FILL ASSEMBLY

P/N

GAUGE

P/N

FASTENERS & HARDWARE

ELECTRONICS P/N

P/N

ELECTRICAL CONNECTORS

Table 11-A Component checklist

Liquefied Petroleum Gas Training Program PAGE 11-7 Liquefied Petroleum MODULE 11: EQUIPMENT LAYOUT & DESIGN Gas

MODULE REVIEW ITEMS

Note to Technician: Consider all choices carefully and select the best answer to each. 1. No manufacturers require any special installation training sessions before installing their systems. A. True. B. False.

2. Which is not a consideration for choosing conversion systems suppliers? A. Know the needs of the customer. B. Have the right system for the particular engine. C. Know what the manufacturer might not offer. D. Know the needs of the system manufacturer.

3. Which is not a good consideration for choosing a conversion system? A. Ordering from only one vendor. B. Time of installation. C. Overall cost of installation. D. Experience of choosing systems.

4. Which is a correct component-to-component item in a checklist? A. Fuel filter to vaporizer. B. Fuel filter to regulator. C. Regulator to automatic fuel lockoff. D. Hydrostatic relief valve to vaporizer.

5. If necessary, move the catalytic converter to a more suitable position. A. True. B. False.

6. If repositioned, the exhaust system should not be: A. Securely mounted. B. Insulated. C. Restricted. D. Leak and rattle free.

7. When inserting mounting brackets and fastners, do not damage: A. Hoses. B. Wires. C. Cables. D. All of the the above.

8. NFPA 58 does not give vent sealing installation guidelines for: A. Fittings. B. Tanks. C. Hoses. D. Valves.

Liquefied Petroleum Gas Training Program PAGE 11-8 Liquefied Petroleum MODULE 11: EQUIPMENT LAYOUT & DESIGN Gas

9. When enclosing tanks, which is a safety consideration? A. Excess weight. B. Access to line components. C. Access to remote fill port. D. All of the above.

10. Carpet or floor coverings should not be fitted over: A. Fuel lines. B. Moving parts. C. Tank supports. D. Tanks.

Liquefied Petroleum Gas Training Program PAGE 11-9 Liquefied Petroleum MODULE 11: EQUIPMENT LAYOUT & DESIGN Gas

MRI SCORING KEY

1. B 2. D 3. A 4. B 5. B 6. C 7. D 8. C 9. A 10. B

Liquefied Petroleum Gas Training Program

1 MODULE 11: Equipment Layout & Design 2 PRELIMINARY CONSIDERATIONS FOR SELECTING CONVERSION EQUIPMENT • Some mfgs require specialized training 3 CONVERSION SYSTEM COMPANIES AND SUPPLIERS • Many systems and vendors • Know customers' needs • Know emissions regulations for operation area 4 SYSTEM SPECIFICATIONS, COST, AVAILABILITY, AND WARRANTIES • Conversion time factor • Availability for particular vehicle • Parts availability • Warranty options; OEM compatibility 5 DRAW SCHEMATIC OF VEHICLE LAYOUT • Use vehicle outline template • Clarity; labels; symbols; key • Refer to schematic frequently during installation 6 11-1 TYPICAL LPG INSTALLATION DIAGRAM 7 11-2 PROPOSED CONVERSION LAYOUT 8 COMPONENT-TO-COMPONENT CHECKLIST • Know which components are separate or combined • Know the in-line order of components 9 MEASURE VEHICLE AND SIZE COMPONENTS FOR CONVERSION • Table 11-A 10 SAFETY GUIDELINES • Consult local safety authorities before starting conversion • Refer to NFPA 58 11 EXHAUST REROUTING • Rerouting may be necessary • Do not move the catalytic converter • Shield the tank; route fuel supply away from heat • Use proper pipe bending equipment 12 HEAT SHIELDING • Bent steel or aluminum sheet • See NFPA 58 or Module 9 for protection regulations 13 VAPOR TIGHT COMPARTMENT • Completely insulated trunk or compartment • Valves enclosed in a sealed, tight, vented cover 14 11-3A VAPOR TIGHT COMPARTMENT 15 11-3B VAPOR COVER IN PLACE 16 EQUIPMENT PROTECTION • Some components may need shields or heavy protection • Heat, road debris, obstacles, collisions • School buses 17 COSMETICS • Covers for tanks and carpeting • Space lost by such additions • Safety requirements 18 COMPARTMENT • Access • OEM equipment maintained MODULE 11: Equipment Layout & Design

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 11-1

PRELIMINARY CONSIDERATIONS FOR SELECTING CONVERSION EQUIPMENT

• Some mfgs require specialized training

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 11-2

CONVERSION SYSTEM COMPANIES AND SUPPLIERS

• Many systems and vendors • Know customers' needs • Know emissions regulations for operation area

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 11-3

SYSTEM SPECIFICATIONS, COST, AVAILABILITY, AND WARRANTIES

• Conversion time factor • Availability for particular vehicle • Parts availability • Warranty options; OEM compatibility

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 11-4

DRAW SCHEMATIC OF VEHICLE LAYOUT

• Use vehicle outline template • Clarity; labels; symbols; key • Refer to schematic frequently during installation

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 11-5

11-1 TYPICAL LPG INSTALLATION DIAGRAM

West Virginia University

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 11-6

11-2 PROPOSED CONVERSION LAYOUT

West Virginia University

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 11-7

COMPONENT-TO-COMPONENT CHECKLIST

• Know which components are separate or combined • Know the in-line order of components

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 11-8

MEASURE VEHICLE AND SIZE COMPONENTS FOR CONVERSION

• Table 11-A

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 11-9

SAFETY GUIDELINES

• Consult local safety authorities before starting conversion • Refer to NFPA 58

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 11-10

EXHAUST REROUTING

• Rerouting may be necessary • Do not move the catalytic converter • Shield the tank; route fuel supply away from heat • Use proper pipe bending equipment

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 11-11

HEAT SHIELDING

• Bent steel or aluminum sheet • See NFPA 58 or Module 9 for protection regulations

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 11-12

VAPOR TIGHT COMPARTMENT

• Completely insulated trunk or compartment • Valves enclosed in a sealed, tight, vented cover

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 11-13

11-3A VAPOR TIGHT COMPARTMENT

Photo Copyright Harris Fogel

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 11-14

11-3B VAPOR COVER IN PLACE

Photo Copyright Harris Fogel

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 11-15

EQUIPMENT PROTECTION

• Some components may need shields or heavy protection • Heat, road debris, obstacles, collisions • School buses

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 11-16

COSMETICS

• Covers for tanks and carpeting • Space lost by such additions • Safety requirements

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 11-17

COMPARTMENT

• Access • OEM equipment maintained

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 11-18

MODULE 12: Fuel Tank Installation

State of Oklahoma College of the Desert West Virginia University

Liquefied Petroleum SECTION 12: FUEL TANK INSTALLATION Gas

CONTENTS

OBJECTIVES ...... 12-i INSTRUCTOR NOTES ...... 12-ii GASOLINE FUEL TANK ...... 12-1 IF THE GASOLINE TANK IS LEFT IN PLACE...... 12-1 IF THE GASOLINE TANK IS TO BE REMOVED...... 12-1 STORAGE SPACE VERSUS FUEL TANK PLACEMENT ...... 12-2 PROPANE FUEL TANK INSTALLATION ...... 12-2 INSTALLATION STEPS...... 12-4 MULTIPLE FUEL TANK INSTALLATION...... 12-7 SCHOOL BUS FUEL TANK INSTALLATION...... 12-7 FUEL TANK INSTALLATION IN ENCLOSED COMPARTMENTS...... 12-8 MODULE REVIEW ITEMS ...... 12-11 MRI SCORING KEY ...... 12-13 OVERHEAD TRANSPARENCY MASTERS

Liquefied Petroleum Gas Training Program

PAGE 12-i Liquefied Petroleum SECTION 12: FUEL TANK INSTALLATION Gas

OBJECTIVES

At the completion of this module, the technician will be able to: • Decide whether or not to remove the gasoline tank, and discuss the considerations of both decisions. • Assess remaining storage space vs. fuel tank placement. • Discuss considerations of fuel tank location and applications. • Install the fuel tank(s) and related components correctly and safely. • Discuss the considerations for mounting tanks in school buses. • Discuss the considerations for mounting tanks in enclosed compartments.

Liquefied Petroleum Gas Training Program PAGE 12-ii Liquefied Petroleum SECTION 12: FUEL TANK INSTALLATION Gas

INSTRUCTOR NOTES

INSTRUCTOR MATERIALS/MEDIA NEEDED Overhead projector or LCD panel/projection equipment Master overhead transparencies or Microsoft PowerPoint 4.0 presentation file Mod12.ppt

Note: Slides correspond to text as indicated by icon

STUDENT MATERIALS/MEDIA NEEDED Module 12: Fuel Tank Installation

OVERHEAD TRANSPARENCY MASTERS The printouts enclosed with this module are taken from the Microsoft PowerPoint 4.0 presentation file Mod12.ppt . Instructors planning to use overhead projectors should make transparencies from these printouts on a copier (or laser printer designed to safely print to acetate.

Note: Please review Module 25: Training of Trainers for more hints on instructional needs and strategies.

Liquefied Petroleum Gas Training Program PAGE 12-1 Liquefied Petroleum MODULE 12: FUEL TANK INSTALLATION Gas

GASOLINE FUEL TANK Key Points & Notes The technician has the option of removing the gasoline tank on a dedicated propane conversion. However, if it does not interfere with 12-2 the installation of the propane fuel tank, it can be left in place p rovided that it is re n d e red incapable of receiving gasoline. For reasons of safety and liability, it is recommended that the gasoline tank, pump, filter, and lines be removed. Refer to applicable rules and regulations. The customer may request that this equipment be packaged for storage to prevent deterioration in case it must be reinstalled for vehicle disposal.

IF THE GASOLINE TANK IS LEFT IN PLACE: 1. Carefully drain all the gasoline from the tank into an approved container. This must be done outside, away from any possible 12-3 s o u rce of flame or ignition. N o t e : Waste gasoline must be disposed of safely, according to local, state and federal regulations. Use extreme caution if pumping gasoline. The OEM fuel pump or an external pump may be used to transfer the tank into an approved container. Caution: When handling gasoline, or any fuel, use extreme caution as gasoline is highly combustible and toxic to touch and breathe. 2. Refer to manufacturer’s service manual to disconnect and plug the gasoline tank fuel piping and fuel pump circuit. 3. Pour a couple quarts of light weight motor oil into the gasoline tank. The oil will provide a slight film coating to the inner surface of the fuel tank and prevent rust, so the gasoline tank may be reused at a future date if necessary. 4. Secure or remove gasoline filler cap to prevent accidental filling with gasoline, or otherwise render the gasoline tank incapable of receiving fuel. The gasoline filler neck to the tank should also be removed. This also makes space for the propane tank remote fill assembly to be installed in the OEM fill door opening.

IF THE GASOLINE TANK IS TO BE REMOVED: 1. Refer to manufacturer’s service manual for gasoline tank removal. 12-4 2. Drain and seal gasoline fuel system and secure remaining fuel lines. Removal of all lines is recommended. Note: Plug or cap open fuel lines to prevent leaks. 3. If the vehicle has an electrical fuel pump mounted outside the fuel tank, disconnect fuel pump power source, remove fuse and the pump. Note: Disconnecting fuel pump might set computer fault codes (MIL). 4. Insulate and secure all disconnected wiring. 5. On vehicles with mechanical fuel pump, remove fuel pump, then seal and secure gasoline fuel lines. Install appropriate fuel pump cover plate.

Liquefied Petroleum Gas Training Program PAGE 12-2 Liquefied Petroleum MODULE 12: FUEL TANK INSTALLATION Gas

STORAGE SPACE VERSUS FUEL TANK PLACEMENT Key Points & Notes Before settling on the placement of the fuel tank(s), consider that the space the fuel tank(s) will occupy may also be needed for storage 12-5 or cargo. Remember to consider more than just the physical space the tank occupies; consider ground clearance and shields. All parts of the fuel system must be no closer than eight inches from the exhaust unless shielded. The expense of the fuel tank(s) is the other logical limitation of what size(s) of fuel tank(s) you will need. If the minimum fuel tank re q u i rement interf e res with carg o capacity, then a certain amount of creativity may be needed. This f requently re q u i res the fleet operator to determine which has a higher priority – vehicle range or cargo capacity. Fuel tanks can be mounted in many different configurations. The fuel receptacle can typically be located in the gasoline fuel receptacle on dedicated LPG vehicles or in a remote access panel or bracket for bi-fuel LPG vehicles. However, there are many options regarding where to place the fuel receptacle. Refer to Figure 12.1.

12-6

PROPANE FUEL TANK INSTALLATION When determining the fuel tank location and application consider how the tank would be affected in case of an accident. Make 12-7 mountings and brackets secure and build in protection when necessary. For design and layout purposes, ask the following questions: • Are the fuel tank valves protected? • If the fuel tank is going to be mounted in the vehicle compartment, is there a plan for all connectors to be vented? • Is the fuel tank placed in a manner that will provide for minimal damage during collision? The recommended placement is behind the front axle and in front of the rear bumper.

Liquefied Petroleum Gas Training Program PAGE 12-3 Liquefied Petroleum MODULE 12: FUEL TANK INSTALLATION Gas

Rear Key Points & Notes Front 12-9

Plane of lowest structural components, etc., forward of container

Courtesy of NFPA 12-2 Tank installation clearances

• Is there adequate road clearance if the fuel tank is mounted under the vehicle? The tank must be installed so that the lowest structural part of the tank (valves, guard, brackets) extends no lower than the lowest point of the vehicle forward of the tank itself (engine, transmission, cross member or exhaust). Refer to Figure 12-2. • Consider the angle from the tire footprint to the front and rear bumpers. • Is there clear access to the other side of the mounting surface or is there anything that could be harmed there? In some cases the mounting brackets require reinforcement plates to be placed on both sides of the selected frame areas. • Are the fuel tank(s) easy to guard, shield, and vent if necessary? The fuel tank(s) mounting location(s) must include suitable surfaces and room for mounting the shields, guards, and vents. • Is there a good route for the fuel line, connections, stress loops or valves to reach the fuel tank(s)? 12-8

12-10

Liquefied Petroleum Gas Training Program PAGE 12-4 Liquefied Petroleum MODULE 12: FUEL TANK INSTALLATION Gas

• Is the intended mounting surface sturdy enough for the fuel Key Points & Notes tank(s)? It is recommended that the mounted fuel tank(s) be able to withstand a force four times the full weight of the fuel tank(s) in all six directions. • Is the entire fuel tank(s) mount apparatus sturdy enough to stay in place with a force of four times the full weight of the tank(s) in all six directions? • Is there room to install the vapor barrier? Where will leaks be vented? Is the vent tube route clear of obstructions? • Is there enough room for the mounting brackets? The brackets a re larger than the fuel tank(s) and re q u i re extra room for the flanges that must be bolted together. • Will the shape of the brackets allow the fuel tank(s) to be installed once the brackets are bolted down? The orientation of the installed brackets may be such that the brackets will interfere with placing the fuel tank(s) into the brackets.

12-13

12-12

Photo © Harris Fogel 1 2 - 4 Saddle tanks – Note space left for vehicle specific cargo container. Inset Close-up of mounting bracket.

INSTALLATION STEPS 1. D e t e rmine the best location for the tank on the vehicle. Most regulations require that the tank be positioned so it is protected 12-11 f rom road hazards and possible collision damage. The tank cannot be mounted on top of the vehicle, ahead of the front axle, or beyond the rear bumper. Valves and fittings and tank structure must not protrude beyond the top, sides, or bottom of the vehicle. The tank(s) should be located away from the exhaust system or other sources of heat. If clearance is a problem, a heat shield should be installed. The minimum re c o m m e n d e d clearance from exhaust systems is eight inches. Refer to Figures 12-4, 12-5 and 12-6

Liquefied Petroleum Gas Training Program PAGE 12-5 Liquefied Petroleum MODULE 12: FUEL TANK INSTALLATION Gas

Remote fill in canopy 12-14

Passenger vehicle tank in trunk. Note: Seal shell vapor cover not shown

Outage Pressure gauge relief valve Remote sender

Liquid supply line Filler valve

Bracket/ Rubber Filler box grommet Filler valve & Pressure outage gauge relief vent from tank 12 - 5 In t e r nal tank applications

12-15

Bracket/ Filler box

Filler valve & Outage outage gauge gauge from tank

Filler valve Vapor Safety plug relief valve

Remote Liquid sender supply line 12-6 Under vehicle mounted tank applications

Liquefied Petroleum Gas Training Program PAGE 12-6 Liquefied Petroleum MODULE 12: FUEL TANK INSTALLATION Gas

Key Points & Notes

12-16

2. Make a trial fit of the fuel tank to see how everything lines up and ensure that it fits within the limitations previously mentioned. 3. Install the tank mounting brackets. The mounting must be strong enough to withstand a force of four times the weight of the full fuel tank, in any direction, without deforming the vehicle, mounting brackets or fasteners. These bolts should be a Grade 8 or stronger 1/2 inch bolts. Install backing plates for maximum s t rength. Backing plates are not necessary on frame mounted brackets but are re q u i red on brackets attached to the body or chassis sheet metal. These backing plates should be a minimum of four square inches surface area. A minimum of two bolts per mounting bracket (four where necessary) are required to ensure a secure mount. Use lock washers or lock nuts with fasteners.

12-17

Courtesy of Manchester Tank 12-8 Installing fuel tank under a vehicle body.

Liquefied Petroleum Gas Training Program PAGE 12-7 Liquefied Petroleum MODULE 12: FUEL TANK INSTALLATION Gas

Key Points & Notes

12-18

4. Bolt the fuel tank in place. The tank must be correctly oriented so: a) The valves will be in the proper position recommended by the tank manufacturer, to en s u r e proper operation. b) The data plate is easily visible. Refer to Chapter 2 for more information on tanks. c) The hand valve for fuel supply is accessible without removing any guards or equipment.

MULTIPLE FUEL TANK INSTALLATION 12-20

When several tanks are 12-19 used, a check valve must be installed in the liquid fuel lines to prevent transfer of liquid p ropane between the tanks. All other steps a re identical for single tank installation. The tanks should be mounted so that weight is distributed evenly and the suspension and Photo © Harris Fogel handling of the vehicle 12-10 Under body bracket mount are not compromised.

SCHOOL BUS FUEL TANK INSTALLATION Special fuel tanks and mounting procedures are required for school bus installations. These tanks usually have heavy duty reinforced 12-22 brackets with a larger surface area. Refer to NFPA 58 and local regulations. Refer to Figure 12-12.

Liquefied Petroleum Gas Training Program PAGE 12-8 Liquefied Petroleum MODULE 12: FUEL TANK INSTALLATION Gas

Key Points & Notes

12-21

Photo © Harris Fogel 12-11 Two-tank valve installed. FUEL TANK INSTALLATION IN ENCLOSED COMPARTMENTS A tank that is mounted in an enclosed compartment (such as trunk or passenger compartment) must have a working pre s s u re of at 12-24 least 312.5 psi and have gas tight vapor shield to seal the tank or fittings or both from the passenger compartment. NFPA 58, 8-2.7 lists the following means: 1. The compartment containing the tank fittings must be sealed from the passenger compartment, using approved materials.

Ported relief 12-23

B77l Bracket Remote fill for school bus using existing gasoline filler door Filler valve & outage gauge Hose from tank required Relief valve Vapor

Service line valve Filler valve Liquid Remote supply Outage gauge sender line

West Virginia University 12-12 Special school bus tank application

Liquefied Petroleum Gas Training Program PAGE 12-9 Liquefied Petroleum MODULE 12: FUEL TANK INSTALLATION Gas

Key Points & Notes

12-25

2. The tank(s) must be designed so the valves and fittings are routed outside of the passenger compartment. 3. The most common tank used currently is one that is manufactured with a vapor seal cover or fitted with a vapor seal that meets NFPA 58 provisions. In all of the above, containers must be fitted so that no gas from fueling or normal operations enters the passenger compartment or trunk, which may be accomplished by installing fixed re m o t e

Double back 80% automatic 12-26 Seal-shell cover check valve stop fill device

80% outage valve

Through 8 x 1/2” 4 x 1/4” vehicle floor straight fitting straight fitting or compartment wall Body panel Nut 8 x 1/2” elbow fitting

Seal-shell Mounting for passenger bolt car trunk or enclosed 4 x 1/4” compartment Back Remote fill elbow assembly installation fitting up plate West Virginia University 12-14 Detail of fuel line fill.

Liquefied Petroleum Gas Training Program PAGE 12-10 Liquefied Petroleum MODULE 12: FUEL TANK INSTALLATION Gas fueling connections. Any spark producing equipment, such as Key Points & Notes radio equipment, must also be isolated from tank(s), valves, and fittings. In addition, the enclosed compartment must be vented outside the vehicle at the lowest point. See Module 13, Ta n k Plumbing.

Liquefied Petroleum Gas Training Program PAGE 12-11 Liquefied Petroleum SECTION 12: FUEL TANK INSTALLATION Gas

MODULE REVIEW ITEMS

Note to Technician: Consider all choices carefully and select the best answer to each. 1. The gasoline tank must always be removed on a dedicated propane mono fuel conversion. A. True. B. False.

2. In case the gasoline fuel tank is to be reused at a later date it is recommended to coat the inner surface of the tank with _____ to prevent rust. A. Water. B. Gasoline. C. Motor oil. D. None of the above.

3. Before settling on the placement of the fuel tank, which of the following should be considered? A. Need for storage and cargo. B. Ground clearance. C. Size of the vehicle. D. All of the above.

4. In a dedicated LPG vehicle the fuel receptacle can typically be located in the old gasoline fuel receptacle. A. True. B. False.

5. The first step to installing a propane fuel tank should be... A. Planning the layout. B. Installing the brackets and mounts. C. Protecting the fuel tank valves. D. Venting the vehicle fuel compartment.

6. When installing a fuel tank, the following should be taken into consideration... A. Ventilation. B. Repercussions of an accident. C. Storage capacity. D. All of the above.

7. The fuel tank must be installed so the lowest structural point of the tank extends no lower than _____. A. Eight inches from the ground. B. The highest point of the vehicle. C. The lowest point of the vehicle. D. None of the above.

8. It is recommended that a mounted fuel tank(s) be able to withstand a force of _____ times the full weight of the tank(s). A. 4. B. 6. C. 8. D. None of the above.

Liquefied Petroleum Gas Training Program PAGE 12-12 Liquefied Petroleum SECTION 12: FUEL TANK INSTALLATION Gas

9. A propane tank cannot be mounted ... A. On top of the vehicle. B. Beyond the rear bumper. C. Ahead of the front axle. D. All of the above.

10. The minimum recommended clearance from the exhaust is _____ inches. A. 6. B. 8. C. 10. D. 12.

11. When several tanks are used, a _____ must be installed in the liquid fuel lines to prevent transfer of liquid propane between the tanks. A. Hand valve. B. Check valve. C. Heat shield. D. All of the above.

12. When mounting a tank in an enclosed compartment, what safety components are necessary? A. Heavy duty brackets and mountings. B. Heat shield. C. Vapor shield. D. None of the above.

13. A tank that is mounted in an enclosed compartment must have a working pressure of at least _____. A. 212 psi. B. 312.5 psi. C. 500.5 psi. D. None of the above.

14. If a tank is mounted in an enclosed compartment, the tank(s) must be designed so that the valves and fittings are routed inside of the passenger compartment. A. True. B. False.

15. When installing tanks within an enclosed compartment it is important to consider the following: A. Containers must be fitted so that no gas from fueling enters the passenger compartment. B. Install fixed remote fueling connections. C. Isolate any spark producing equipment from tanks, valves and fittings. D. All of the above.

Liquefied Petroleum Gas Training Program PAGE 12-13 Liquefied Petroleum SECTION 12: FUEL TANK INSTALLATION Gas

MRI SCORING KEY

1. B 2. C 3. D 4. A 5. A 6. D 7. C 8. A 9. D 10. B 11. B 12. C 13. B 14. B 15. D

Liquefied Petroleum Gas Training Program

1 MODULE 12: Fuel Tank Installation 2 GASOLINE FUEL TANK • Option to keep or remove the gasoline tank 3 IF THE GASOLINE TANK IS LEFT IN PLACE • Drain gasoline from tank • Disconnect and plug the tank fuel piping and pump circuitry • Coat the inner surface of the tank with oil • Secure or remove filler cap 4 IF THE GASOLINE TANK IS TO BE REMOVED • Drain and seal fuel system • Disconnect fuel pump power source • Insulate and secure all disconnected wiring 5 STORAGE SPACE VERSUS FUEL TANK PLACEMENT • Consider needed storage space • Consider ground clearance and shields • Determine priority: – Vehicle range – Cargo capacity 6 12-1 INSTALLED LPG TANK 7 PROPANE FUEL TANK INSTALLATION • Design and layout – Protect the tank valves – Plan for all connectors to be vented – Provide for minimal damage during collision – Provide for adequate road clearance – Guard the fuel tanks 8 PROPANE FUEL TANK INSTALLATION • Fuel tank mounting – Ensure good route for fuel line, connections, stress loops and valves – Ensure sturdy mounting surface – Ensure enough room to install vapor barrier – Ensure enough room for mounting brackets – Ensure the shape of the bracket allows tank to be installed once brackets are bolted down 9 12-2 TANK INSTALLATION CLEARANCE 10 12-3 INSTALLED TANK W/O PLUMBING 11 INSTALLATION STEPS • Determine best location • Make a trial fit • Install the mounting brackets • Bolt fuel tank in place • Ensure valves are in proper position • Ensure data plate is easily visible • Ensure hand valve for fuel supply is accessible 12 12-4 SADDLE TANKS 13 12-4A MOUNTING BRACKET 14 12-5 INTERNAL TANK APPLICATIONS 15 12-6 UNDER VEHICLE MOUNTED TANK APPLICATIONS 16 12-7 UNDERBODY MANIFOLD TANK INSTALLED 17 12-8 FUEL TANK UNDERBODY INSTALLATION 18 12-9 BRACKET AND FASTENER 19 12-10 UNDERBODY BRACKET MOUNT 20 MULTIPLE FUEL TANK INSTALLATION • Use check valve between each tank • Distribute weight of tanks across vehicle 21 12-11 TWO-TANK VALVE 22 SCHOOL BUS FUEL TANK INSTALLATION • Use heavier reinforced brackets • Check NFPA 58, local regulations 23 12-12 SCHOOL BUS TANK APPLICATION 24 FUEL TANK INSTALLATION IN ENCLOSED COMPARTMENTS • Tank compartment must be sealed from passenger compartment • Tanks designed so valves and fitings are routed outside the passenger compartment • Typical tanks have vapor seal covers meeting NFPA 58 guidelines 25 12-13 PASSENGER CAR TANK 26 12-14 FUEL LINE FILL DETAIL MODULE 12: Fuel Tank Installation

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 12-1

GASOLINE FUEL TANK

• Option to keep or remove the gasoline tank

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 12-2

IF THE GASOLINE TANK IS LEFT IN PLACE

• Drain gasoline from tank • Disconnect and plug the tank fuel piping and pump circuitry • Coat the inner surface of the tank with oil • Secure or remove filler cap

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 12-3

IF THE GASOLINE TANK IS TO BE REMOVED

• Drain and seal fuel system • Disconnect fuel pump power source • Insulate and secure all disconnected wiring

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 12-4

STORAGE SPACE VERSUS FUEL TANK PLACEMENT

• Consider needed storage space • Consider ground clearance and shields • Determine priority: – Vehicle range – Cargo capacity

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 12-5

12-1 INSTALLED LPG TANK

Photo Copyright Harris Fogel

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 12-6

PROPANE FUEL TANK INSTALLATION

• Design and layout – Protect the tank valves – Plan for all connectors to be vented – Provide for minimal damage during collision – Provide for adequate road clearance – Guard the fuel tanks

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 12-7

PROPANE FUEL TANK INSTALLATION

• Fuel tank mounting – Ensure good route for fuel line, connections, stress loops and valves – Ensure sturdy mounting surface – Ensure enough room to install vapor barrier – Ensure enough room for mounting brackets – Ensure the shape of the bracket allows tank to be installed once brackets are bolted down

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 12-8

12-2 TANK INSTALLATION CLEARANCE

Front Rear

Plane of lowest structural components, etc., forward of container

Courtesy of NFPA

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 12-9

12-3 INSTALLED TANK W/O PLUMBING

Photo Copyright Harris Fogel

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 12-10

INSTALLATION STEPS

• Determine best location • Make a trial fit • Install the mounting brackets • Bolt fuel tank in place • Ensure valves are in proper position • Ensure data plate is easily visible • Ensure hand valve for fuel supply is accessible

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 12-11

12-4 SADDLE TANKS

Photo Copyright Harris Fogel

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 12-12

12-4A MOUNTING BRACKET

Photo Copyright Harris Fogel

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 12-13

12-5 INTERNAL TANK APPLICATIONS

Remote fill in canopy Passenger vehicle tank in trunk. Note: Seal shell vapor cover not shown

Bracket/Filler box

Pressure relief vent Filler valve & outage gauge from tank

West Virginina University

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 12-14

12-6 UNDER VEHICLE MOUNTED TANK APPLICATIONS

Bracket/Filler box

Filler valve & outage gauge from tank

Liquid supply line

West Virginina University

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 12-15

12-7 UNDERBODY MANIFOLD TANK INSTALLED

Photo Copyright Harris Fogel

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 12-16

12-8 FUEL TANK UNDERBODY INSTALLATION

Courtesy of Manchester Tank

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 12-17

12-9 BRACKET AND FASTENER

Photo Copyright Harris Fogel

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 12-18

12-10 UNDERBODY BRACKET MOUNT

Photo Copyright Harris Fogel

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 12-19

MULTIPLE FUEL TANK INSTALLATION

• Use check valve between each tank • Distribute weight of tanks across vehicle

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 12-20

12-11 TWO-TANK VALVE

Photo Copyright Harris Fogel

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 12-21

SCHOOL BUS FUEL TANK INSTALLATION

• Use heavier reinforced brackets • Check NFPA 58, local regulations

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 12-22

12-12 SCHOOL BUS TANK APPLICATION

Ported relief

Remote fill for school bus using existing gasoline filler door

B77I Bracket Filler valve & outage gauge from tank

Liquid supply line

West Virginina University

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 12-23

FUEL TANK INSTALLATION IN ENCLOSED COMPARTMENTS

• Tank compartment must be sealed from passenger compartment • Tanks designed so valves and fitings are routed outside the passenger compartment • Typical tanks have vapor seal covers meeting NFPA 58 guidelines

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 12-24

12-13 PASSENGER CAR TANK

Photo Copyright Harris Fogel

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 12-25

12-14 FUEL LINE FILL DETAIL

Body panel Remote fill Nut assembly 4x1/4” elbow fitting

Mounting bolt Through vehicle floor 8x1/2” elbow fitting or compartment Back-up plate wall

80% outage valve Seal-shell cover Seal-shell for passenger car trunk or enclosed compartment installation

4x1/4” straight fitting 8x1/2” straight fitting

80% automatic Double back stop fill device check valve West Virginina University

College of the Desert / West Virginia University National Alternative Fuels Training Program (NAFTP) 12-26