Dry Pipe Valve

Flange x Flange - AF

Manufactured by: Central Sprinkler Company 451 North Cannon Avenue, Lansdale, Pennsylvania 19446

pressure, utilizing either a factory air Product supply, or an optional automatic air compressor. 3" Dry Description Central’s Accelerator (quick- opening device) may also be easily The Central Dry Pipe Valve is a dry connected to the Dry Pipe Valve Pipe pipe sprinkler system water-supply Trim. control valve that makes possible the The Dry Pipe Valve is available in installation of sprinkler systems in the flange-by-flange style. Valve & buildings subject to freezing The Valves are Listed by Under- temperatures. It is designed so that writer’s Laboratories, and Approved air pressure in the piping system will by Factory Mutual for use in fire Trim hold back water pressure at the valve sprinkler systems with a maximum until such time as a sprinkler is working pressure of 175 psi. activated. Upon such activation the air pressure in the system will decay sufficiently to cause automatic Technical operation of the valve and admission of water into the system. Data The valve has a 5:1 pressure differential ratio. The overall clapper area, exposed to system air pressure, Model: AF is five times the area sealing against Style: Flange-x-Flange the water supply. These two areas Size: 3" (76.2 mm) are concentric to each other, and are Approvals: U.L., U.L.C., F.M. separated by an intermediate Maximum Working Pressure: 175 psi chamber normally maintained at Factory Hydro Test: 100% at 350 psi atmospheric pressure. (with clapper open) The Dry Pipe Valve Trim package Standard Finish: Blue enamel includes the necessary valves, Flange Specifications: gauges, fittings and nipples to provide AF Inlet - Class 125 ANSI B16.1 an air supply connection, priming AF Outlet - Class 125 ANSI B16.1 3 water connection, drain connections, Piping Take-Out: 13 ⁄4" (34.9 cm) alarm connection, accelerator Required Accessories: connections and alarm test bypass Standard Trim (as shown) (Note: Accelerator trim sold Optional Accessories: separately). The Dry Pipe Valves are Air Maintenance Device Listed/Approved with Central's Trim Air Compressor only. Any substitutions or omissions Accelerator and Trim may void such Listings and Pressure Alarm Switch Approvals, without prior approval Water Motor Alarm from Central Sprinkler. Low Air Pressure Switch Central’s Air Maintenance Device is Mfgr. Source: U.S. easily installed, and is designed to Weight: Valve - 80 lbs. (36.24 kg) establish and regulate system air Trim - 38 lbs. (17.21 kg) No. 10-3.2 Figure 1 Dry Pipe Valve Section

Flanged Outlet - Model AF Air Supply Connection (3/4" NPT)

9 Cover Gasket 10 Cover Bolt (3/4")

Body 1

Priming 8 Cover Connection (3/4" NPT) 13 3/4" 7 Clapper Assembly

Air Seat Ring 3 4 Body Bushing

Inter. Chamber 6 Pipe Plug (3/8") Connection (3/4" NPT) 5 Hinge Pin

2 3/4" Water Seat 2 1 7/8" Ring

4 1/4" Main Drain Connection (1 1/4" NPT)

Note: The Clapper Assembly may be removed from the body of the Dry Pipe Valve Note: Theby removing clapper assembly the two may 3/8" be plugs removed (#6) fromand theremoving body of the the hingedry pipe pin valve (#5). by removing the two 3/8" plugs (#6) and removing the hinge pin (#5).

Parts List - 3" Dry Pipe Valve (Model AF Part No. 2213)

Identification Number Number Required Description Part Number 1 1 Body 300-188-00 2 1 Water Seat Ring* 300-183-00 3 1 Air Seat Ring* 300-184-00 4 2 Body Bushing 300-187-00 5 1 Hinge Pin 818-10-100 6 2 Pipe Plug, 3/8"-18 NPT 818-12-000 7 1 Clapper Assembly 300-186-00 8 1 Cover 300-02-000 9 1 Cover Gasket 300-04-000 10 6 Cover Bolt 3/4"-10 x 2" Long 600-03-000 *Not field replaceable.

2 Figure 2 Dry Pipe Valve Clapper Assembly

Plan View

Latch Pin 8

9 Retaining Ring 2 6 Clapper Clapper Bushing Bushing 1 Clapper

Section View

Latch Spring 10

7 Latch 4 3 5 Retaining Rubber Bolt Plate Seal

Parts List - 3" Clapper Assembly (Assembly No. 300-186-00)

Identification Number Number Required Description Part Number 1 1 Clapper 300-182-00 2 2 Clapper Bushing (thru body) 818-08-000 3 1 Rubber Seal 300-180-00 4 1 Retaining Plate 300-181-00 5 5 1/4"-20 x 5/8" Hex Head Bolts 300-16-000 6 2 Clapper Bushing (thru latch) 818-08-000 7 1 Latch 300-10-000 8 1 Latch Pin 300-23-000 9 2 Retaining Ring 300-22-000 10 1 Latch Spring 300-21-000

3 of air in the sprinkler piping. The Drawings Operation larger the volume, the slower the air The dry pipe system working pressure decays, which slows drawings must show: operation of the Dry Pipe Valve. 1. The manufacturer, style, model Central’s Accelerator is an Approved number, and size of the Dry When the Dry Pipe Valve is in the Quick Opening Device (QOD) that is Pipe Valve. set position, the rubber-faced clapper sensitive to a rapid, small drop in 2. The total number of sprinklers is tightly closed on two concentric system air pressure. Its quick on each dry pipe system, and, seat rings. The inner ring is the operation directs system air pressure 3. The capacity (gallons) of each supply water ring and the outer ring to the underside of the clapper in the dry pipe system. is the system air ring. The annular area of the intermediate chamber. As Pendent sprinklers in dry pipe space between the two seat rings the air pressure in the intermediate systems must be of the dry pendent (intermediate chamber) is open to the chamber rises to the level of the type in areas that are subject to atmosphere via the alarm connection system pressure, the differential freezing. trim piping to the normally open pressure ratio on the valve clapper is Dry pipe systems that supply automatic ball drip valve. reduced rapidly. The dry pipe valve freezer areas must be equipped with Priming water is provided above will then trip much sooner than would a local, Low Air Pressure Alarm which the clapper up to the level of the have been possible without the may be connected to the system riser priming connection. Above the accelerator. The operation of just above the Dry Pipe Valve. For priming water, compressed air (or Central’s Accelerator is described in “freezer area” systems, a desiccant nitrogen) is maintained at a pressure greater detail in a separate Central air dryer should be provided in the air sufficient to hold the clapper closed. bulletin. supply line to remove moisture from The Dry Pipe Valve has a differential the compressed air. trip ratio of approximately 5 to 1. Thus the valve will open (trip) when Design Dry System Capacity the air pressure in the system piping If the dry pipe system capacity is reduced to approximately one-fifth exceeds 500 gallons, the Dry Pipe of the water supply pressure. Data Valve must be equipped with a The purpose of the priming water is Central Accelerator. See the appro- to assist in providing a positive seal DESIGN CONSIDERATIONS priate Central Bulletin for details. at the air seat ring to prevent air from The capacity (gallons) of the piping escaping into the intermediate General system may be calculated using the chamber and on to the atmosphere. The Central Model AF Dry Pipe following table: The clapper will remain in the closed Valves must be installed in the position as long as the air pressure in vertical position. They should be Capacity (gal./ft.) the piping system is maintained at located in a sprinklered area not Diameter (in.) Sch. 40 Sch. 10 the proper level. subject to freezing conditions, such as a well-lighted and heated valve When a sprinkler operates, the air 3/4 .028 — pressure in the piping system decays house or similar enclosure having 1 .045 .049 due to the air escaping from the sufficient room to enable ease of 1 1/4 .078 .085 opened sprinkler. When the air installation, care and maintenance. 1 1/2 .106 .115 pressure has decayed to the point When properly installed, the trim 2 .174 .190 that it is no longer adequate to hold on the Dry Pipe Valve protrudes the 2 1/2 .248 .283 the clapper shut, the water supply following horizontal distances from 3 .383 .433 pressure lifts the clapper which the center line (C.L.) of the riser: 4 .660 .740 6 1.501 1.6491 automatically latches in the open 8 2.663 2.7762 position. Water flows into the system Trim 3" piping to the open sprinkler(s). At the 1 Protrusion* Valve 0.134" wall pipe same time, water flows via the 2 0.188" wall pipe intermediate chamber into the alarm C.L. to left 15" 3 Schedule 30 pipe connection trim piping (closing the C.L. to right 17" C.L. to rear 8" automatic ball drip valve) and In accordance with current NFPA continues on through the alarm line * When the observer is facing the 13, the maximum allowable capacity to operate the pressure actuated valve body cover plate. of a single dry pipe system is nor- alarm switch and/or the water motor mally 750 gallons. The capacity may alarm. exceed 750 gallons only if water can When a sprinkler opens, the be delivered to the inspector’s test resulting air pressure decay is connection in 60 seconds or less. inversely proportional to the volume

4 Air Compressor Friction Loss The compressed air supply for the For use in hydraulic calculations, Installation dry pipe system is usually provided by the pressure loss through the Dry a continuously available, electrically Pipe Valve may be expressed in driven, air compressor which is equivalent length of schedule 40, automatically controlled to turn on C=120 pipe as follows: General and off at the designed minimum and maximum pressures, respectively. 3" Valve = 29 feet Dry Pipe Valves must be installed in After initial pressurization of the a sprinklered area not subject to system, the air supply is maintained Drainage (per NFPA 13) freezing conditions, such as a well- through an in-line, 1/8” orifice in the The dry pipe system must be lighted and heated valve house or piping of the Air Maintenance Device. designed so that all portions of the similar enclosure having sufficient The orifice is small enough that when piping system may be drained. In room to enable ease of installation, a sprinkler opens, the air supply will order to assure proper drainage: care and maintenance. not interfere with the operation of the 1. Branch lines, cross and feed Prior to installing the Dry Pipe Dry Pipe Valve by rapidly supplying mains shall be pitched in Valve in the piping system, the water additional air pressure to the upper accordance with NFPA 13, Sec. supply line must be thoroughly chamber of the Dry Pipe Valve. 3-6.1.3. flushed to assure that no foreign The air compressor must be 2. Trapped sections of piping must matter is present. adequately sized to be able to bring be equipped with auxiliary The valve must be installed in a the system air pressure up to the drains as follows: vertical position in the system piping. design level in 30 minutes or less. a. If the trapped section is less Trim according to the Trim Assembly The required size of the air than 5 gallons capacity, Diagram on page 7. compressor in C.F.M., may be provide a 3/4” valve with plug Remove the hand hole cover and determined from the following or with nipple and cap. gasket and check the valve clapper equation: b. If the trapped section is for freedom of movement. C.F.M. = 0.012 X System Capacity greater than 5 gallons In order to place the Dry Pipe Valve (gallons), where C.F.M. is the free air capacity, provide a drum drip into operation, the valve must be “set” delivery in cubic feet per minute (2” x 12” pipe nipple with a 1” (see Setting Procedure on page 8). based on standard air at sea level. valve on each end) with the The system side of the valve clapper outlet valve equipped with a assembly must be primed with water plug or nipple and cap. to the level of the priming connection.

Note: Priming water is as follows: Friction Loss 3" = 1/2 Gallon

The system piping must be 3" subsequently pressurized with air (or nitrogen) via the air connection. After priming and pressurization of the Dry Pipe Valve, the main system water control valve must be opened fully. After initial installation, the alarm test, main drain test and trip test(s) must be performed and the system reset and placed in service. It is recommended that Central’s Automatic Air Maintenance Device be permanently connected to the system to avoid the possibility of false valve trips which may result from small piping leaks gradually lowering system air pressure. If difficulty in performance is experienced, Central Sprinkler Company should be contacted if any field adjustment is to be made.

5 Figure 3 - Set Position

System

Pressure Relief Air

Air Supply Fill Port

Priming Water Level Drain Alarm Line Condensate (to Water Gong) Drain

Ball Drip

Alarm Test Main Main Supply Drain

Figure 4 - Activated Position

System

Pressure Relief Water

Air Supply Fill Port

Priming Alarm Line Drain (to Water Gong) Condensate Drain

Ball Drip

Alarm Test Main Main Supply Drain 6 Figure 5 Trim Assembly Diagram - 3" Dry Pipe Valve Model AF

Normal Valve Position 3 Normally Closed 8 Normally Open 15 Normally Closed 19 Sealed Open 27 Normally Open *Indicates Accelerator Trim Connection Point. 37 (Plug) Normally Screwed Tight Note: Detail trim kit is available without gauges. 40 Normally Closed Detail Detail Number Description Quantity Number Description Quantity 1 1 1/4" x 2 1/2" Nipple 1 24 3/4" x 3/4" x 1/4" Tee 2 2 1 1/4" x 1 1/4" x 1/2" Tee 2 25 3/4" 90° Elbow 1 3 1 1/4" MxF Ball Valve 1 26 1/2" Relief Valve 1 4 1 1/4" x 4" Nipple 1 27 3/4" Globe Valve 1 5 1/2" x 1 1/2" Nipple 6 28 1/2" Pipe Plug 2 6 1/2" x 1/4" x 1/2" Tee 1 29 3/4" x 1/2" Red. Bush. 2 7 1/4" x 2" Nipple 1 30 1/2" x 5" Nipple 1 8 1/4" 3-way Globe Valve 2 31 1/2" x 1/2" x 1/4" Tee 1 9 1/4" Pipe Plug 3 32 1/2" Ball Drip Valve 1 10 1/4" Close Nipple 4 33 1/2" Drip Cup 1 11 1/4" 90° Elbow 1 34 1/2" Check Valve 1 12 1/2" x 2 1/2" Nipple 2 35 3/4" x 7 1/2" Nipple 1 13 1/2" Union 1 36 3/4" x 3/4" x 1" Tee 1 14 1/2" 90° Elbow 3 37 1" Pipe Plug 1 15 1/2" Ball Valve 1 38 3/4" x 1/4" Red. Bush. 1 16 1/2" x 7 1/2" Nipple 1 39 1/4" 90° Street Elbow 1 17 3/4" x 3/4" x 1/2" Tee 2 40 1/4" Globe Valve 2 18 3/4" x 2" Nipple 2 41 1/4" Gauge, Air 1 19 3/4" Ball Valve 1 42 1/4" Gauge, Water 1 20 3/4" Close Nipple 9 43 1 1/4" x Close Nipple 1 21 3/4" Check Valve 2 44 1/2" x 3" Nipple 1 22 3/4" Cross 1 45 1 1/4" 90° Elbow 1 23 3/4" x 1/2" x 3/4" Tee 1

7 Setting Procedure the closed and fully-seated position. accelerator may proceed concurrent Step 1. Close the main water supply Do not force the clapper in attempting with establishing the air pressure in control valve to the sprinkler system to make the Dry Pipe Valve tight. Do the system. (OS&Y, PIV or other). not use grease or other sealing materials on the seat rings or Step 16. Open the Air Supply Step 2. Close all valves in the Dry rubber seal. Control Valve (Fig. 5, #27) and admit Pipe Valve Trim, except the 1/4" air to the system. If the system is three-way valves (Fig. 5, #8) at the Step 9. Reinstall the valve body equipped with an automatic Air Air Pressure Gauge and Water Cover and Gasket, being careful to Maintenance Device, refer to the Pressure Gauge. tighten the bolts evenly in staggered appropriate Central Bulletin for fashion. detailed instructions. Step 3. Open the system main drain valve, the system inspector’s test Step 10. Open the Priming Supply Note: It is good practice to build valve, and all system auxiliary drain Plug (Fig. 5, #37), while making sure up the air pressure on the system valves connected to the piping. that the Condensate Drain Valve (Fig. to 10 psi and then individually Replace any sprinklers which may 5, #40) is closed. Prime the Dry Pipe open the auxiliary drains to force have activated. Valve by slowly pouring water into the any remaining water from the low By keeping the inspector’s test Priming Supply. Stop pouring when points in the system. When dry air connection open, the system piping water remains visible in the Priming starts to discharge, close the will be maintained at atmospheric Supply Line. valve(s) tightly and replace the pressure and the test connection will plug or cap. serve as a vent during system Note: Priming water is as follows: drainage and during priming of the Step 17. Continue to admit air into Dry Pipe Valve. 3" = 1/2 Gallon the system until the Air Pressure Gauge (Fig. 5, #41) registers the air Step 4. After all drainage has Step 11. Open the Condensate pressure required to hold the Dry stopped, tightly close all auxiliary Drain Valve to remove excess Pipe Valve closed against the water drain valves. Leave the inspector’s priming water from the Dry Pipe supply pressure. The recommended test valve and system main drain Valve. air pressure is a function of the water valve open. supply pressure as shown below: Step 12. Close the Condensate Step 5. Remove the valve body Drain Valve and replace the Priming Cover and Gasket (Fig. 1, #8 & #9). Supply Plug. Water Air (psi) (psi) Min. Max. Caution: Never attempt to remove Step 13. Check the Automatic Ball 50 15* 25 the valve cover while the valve is Drip Valve (Fig. 5, #32) for leakage. 75 25 35 under pressure. 100 35 45 a. If there is little or no leakage, the 125 40 50 Step 6. Lift the clapper assembly clapper is properly seated. 150 40 50 (Fig. 1, #7) and carefully inspect the Continue with the "Setting 175 40 50 water seat ring (Fig. 1, #2), air seat Procedure". ring (Fig. 1, #3), rubber seal (Fig. 2, b. If there is leakage, the clapper is * When an accelerator is installed with #3), and valve body interior. Clean if not properly seated, and the the Dry Pipe Valve, a minimum air necessary. Do not use cleaning priming water is leaking past the pressure of 25 psi is required. compounds which could damage the air seat into the intermediate rubber seal. Be careful not to scratch chamber. The Dry Pipe Valve or dent the seat rings. Damaged seat must be reopened and repaired. Step 18. Again, check the Automatic rings are not field-replaceable. Replace the rubber seal on the Ball Drip Valve for leakage. There clapper if it is worn. After should be none. Step 7. Verify that the clapper performing the necessary assembly moves freely and that the repairs, repeat steps 5 through a. If there is no leakage, the spring-loaded anti-reseat Latch (Fig. 13 above. clapper is properly seated. 2, #7) moves freely under hand- Continue with the "Setting applied pressure. Step 14. Close the system Procedure". inspector’s test valve. b. If there is leakage, the clapper Step 8. Raise the rear portion of the is not properly seated and is anti-reseat Latch so that it clears the Step 15. Clean the Accelerator, if the not holding the priming water. two cast-in-body latching positions, system is so equipped. Refer to the The Dry Pipe Valve must be and lower the clapper assembly to appropriate Central Bulletin for reopened, inspected, and detailed instructions. Cleaning the repaired or replaced. 8 Priming water must be retained in Hydrostatic Test drain pipe. If a full steady stream is the valve before the system can be The 2-hour, 200 psi hydrostatic test not discharging, check the main drain placed in service. After correcting of the sprinkler system piping must be piping for obstructions. any problems, repeat steps 3 through conducted with the valve clapper 18. latched in the open position. The Step 3. Allow the water to flow until rubber seal on the face of the clapper the reading on the Water Pressure Step 19. Activate the air supply to may be ruptured if the valve is tested Gauge drops and stabilizes. Then the Accelerator, if the system is so with the clapper in the closed posi- record this reading. This is the equipped. Refer to the Central tion. The test should be conducted residual pressure. Accelerator Bulletin for instructions. as weather permits, to prevent freezing of the piping. Step 4. Close the main drain valve To prevent a possible false trip of the slowly. Dry Pipe Valve, perform this accelerator activation step prior to Air Test Step 5. Compare static and residual opening the main water supply The 40 psi air pressure test of the pressure readings with any previously control valve. sprinkler system piping must be established or normal readings. If the conducted to verify there are no leaks readings compare favorably, the Step 20. Slowly open the main water that would allow a pressure loss of water supply may be considered supply control valve to the sprinkler 1.5 psi or more during the 24-hour satisfactory. If the readings vary to system. When water starts to test period. any great extent, the condition should discharge from the main drain, slowly be investigated to determine the Acceptance Testing close the main drain valve (Fig. 5, cause. Some possible causes are: After the installation of a Dry Pipe #3). Then fully open the main water System is complete and prior to final supply control valve (O,S&Y, PIV or a. Partially or totally closed water acceptance by the Authority Having other). supply control valves. Jurisdiction, the installer must con- b. Clogged or frozen water supply duct a Main Drain Test, Alarm Test, Step 21. Perform a Main Drain Test mains. and Trip Test. The test results must (see Main Drain Test Procedure). c. Serious leakage at water supply be recorded on the Contractor’s valves or mains. Material and Test Certificate. Step 22. Open the Alarm Test Valve d. Significant modifications to the Refer to the Trim Assembly (Fig. 5, #15), and then perform an water supply system since the Diagram (Figure 5) which correlates Alarm Test (see Alarm Test prior test. This may be verified with the I.D. numbers noted in the Procedure). with the local water supply utility following procedures: or fire department. Step 23. Seal, lock, or otherwise Main Drain Test Procedure secure the Alarm Control Valve (Fig. The purpose of the Main Drain Test Alarm Test Procedure 5, #19) and the main water supply is to show whether or not the normal Unlike wet sprinkler systems, it is control valve in the open position. water supply is available to the not practical to periodically test the The system is now ready for service. system. By comparing the static and operation of the alarm connected to a residual water pressure readings with dry pipe system by opening the Step 24. If alarms connect to a any previously established readings, inspectors test valve normally located central station or fire department, a Main Drain Test can indicate the at the most remote position of the notify the signal receiving station that possible presence of partially closed system piping. The reason being that the system has been placed in valves or other obstructions in the the entire dry system piping would fill service. supply piping. To avoid property with water, hence necessitating time- damage during testing, provision consuming system draining and must be made for proper disposal of resetting. Testing water issuing from the test outlet. If alarms connect to a central The procedure for conducting a station or fire department, notify the main drain test is as follows: signal receiving station prior to and at the completion of the Alarm Test. The procedure for testing the alarm General Step 1. While the Dry Pipe Valve is “set”, and the main drain valve is without tripping the system is as follows: Prior to completion of the installa- closed, note and record the reading tion of a Dry Pipe System, the piping on the Water Pressure Gauge (Fig. 5, #42). This is the static pressure. Step 1. Open the Alarm Test Valve must be tested for strength and water (Fig. 5, #15). This will pressurize the leakage (hydrostatic test) and for air alarm line, cause the pressure alarm leakage (air test). The test results Step 2. Open the main drain valve (Fig. 5, #3) slowly until it is wide switch (if any) to activate and the must be recorded on the Contractor’s water motor alarm (if any) to sound. Material and Test Certificate. open. Verify that a full steady flow of water is discharging from the main 9 . Step 2. Close the Alarm Test Valve Step 4. While observing the Air Note: If there is an Accelerator to silence the sounding device. Pressure Gauge, have the inspector’s attached to the Dry Pipe Valve, test valve opened by an assistant and initial acceptance testing must Trip Test Procedure note the time. include two trip tests, one with and Dry Pipe Valves should be trip tested one without the Accelerator in during warm weather, preferably in Note: If two-way communication is service. the summer to allow all condensation not available, the time of opening to drain from the system piping before the inspector’s test valve may be the onset of cold weather. determined by observing when the Care & Before proceeding with any trip test needle on the Air Pressure Gauge of a Dry Pipe Valve, the water supply starts to move downward. Maintenance line to the system should be thoroughly flushed. The system main Step 5. When the Dry Pipe Valve drain may be used for this purpose. If trips, quickly note the time and the The Central Model AF Dry Pipe there is a hydrant on the supply line, reading on the Air Pressure Gauge. Valves and their accessory devices it should be used to flush the piping (air maintenance device, accelerator, before the main drain is opened. Step 6. Allow water to flow into the pressure alarm switch, water motor system. Note the time when water alarm), should be semiannually Note: Assistance is required to starts to discharge from the examined by experienced and perform some of the operations in inspector’s test connection. qualified personnel, to ensure proper this test procedure. operation and trouble-free service. Step 7. Keep the Inspector’s Test The procedure for conducting a full- Valve open until clean water is Warning: Any system flow trip test is as follows: flowing at the connection. Terminate maintenance or inspection that the test by closing the Inspector’s involves placing a control valve Step 1. While the dry pipe system is Test Valve and then the main water “out-of-service” will eliminate the “in service”, open the main drain supply control valve (O,S&Y, PIV or fire protection normally provided valve (Fig. 5, #3) slowly until it is wide other). by the system. open. Then check to make sure that a full steady flow of water is Step 8. Compare the data on trip Prior to proceeding, be certain to discharging from the main drain pipe. point pressure, trip time, and water secure permission from all Authorities Allow the water to flow at full pressure delivery time to the inspector’s test Having Jurisdiction and notify all long enough to clear the water supply connection, with previous test personnel who may be affected pipe of any accumulation of scale or records. If the data differs to any during system shutdown. A fire watch foreign material. great extent from previous records, during maintenance periods is a the cause should be investigated, and recommended precaution. Step 2. Slowly close the main drain the condition corrected. The owner is responsible for the valve. The Dry Pipe Valve is now proper operating condition of all fire ready for Trip Testing. Step 9. Drain the Dry Pipe System, protection devices and accessories. thoroughly clean the Dry Pipe Valve, The NFPA Standard 25 entitled, Step 3. Note and record the readings replace parts as required, and reset “Inspection, Testing and Maintenance on the Air Pressure Gauge and on the valve (see Setting Procedure). of Water-Based Fire Protection the Water Pressure Gauge. Systems”, contains guidelines and Step 10. The Dry Pipe Valve should minimum maintenance requirements. Caution: Before proceeding, be be provided with an attached tag Furthermore, the Authority Having prepared to record the following which shows the date when the valve Jurisdiction may have additional information; a watch with a sweep was tripped and the name of the regulations and requirements for second hand will be required. person and organization performing maintenance, testing and inspection the test. that must be obeyed. a. Air Pressure reading when the Dry Pipe Valve trips. The organization performing the Inspections b. The time when the inspector’s test should maintain separate records The areas of the Dry Pipe Valve test valve is opened. which show the test results including: and Trim that should be included in c. The elapsed time, in seconds, initial air and water pressures, trip semiannual inspections are described when the Dry Pipe Valve trips. time, trip air pressure, water delivery below. d. The elapsed time, in seconds, time to the inspector’s test connection when water begins flowing from and operating condition of the Dry Clapper Seal the inspector’s test connection. Pipe Valve and accessory devices. (Refer to Figure 2) The rubber seal (#3) should be checked for wear or

10 damage. It should be free of dirt or other foreign substances. If found to Air Pressure Ordering be worn or damaged, the rubber seal Air (or nitrogen) pressure must be should be replaced. If it is dirty, it maintained on the dry pipe system Information should be cleaned. Compounds throughout the year. Dry pipe which could damage the rubber seal systems should not be converted to When placing an order, indicate the must not be used. The rubber seal wet systems during the warm weather full product name. Please specify the should be inspected at any time there season because this will cause quantity, model number, style and is excessive water leakage at the increased corrosion and size. Automatic Ball Drip Valve (Fig. 5, #32). accumulation of foreign matter in the The Dry Pipe Valve does not piping. Maximum allowable air include trim, accelerator, air Clapper Seal Replacement pressure leakage is 1.5 psi per 24 maintenance device, pressure switch (Refer to Figure 2) The rubber seal hours. If this maximum is exceeded, or water motor alarm. Each must be may be replaced by removing the the leaks should be repaired. ordered separately. Clapper Assembly and removing the The Dry Pipe Valves do not include five bolts (#5) holding the Retaining Priming Water Level flange nuts, bolts, and gaskets or Plate (#4) against the rubber seal and (Refer to Figure 5) Loss of priming mechanical grooved couplings. to the clapper (#1). water, either through evaporation into These items must be ordered the system or by seepage past the air separately. Seat Rings seat ring, could result in operation of (Refer to Figure 1) The air (#3) and the Dry Pipe Valve. Conversely, Availability and Service: Central water (#2) seat rings should be accumulation of additional water from sprinklers, valves, accessories, and cleaned and checked for damage condensation in the system could other products are available such as nicks, scores or dents. Seat raise the priming water level up into throughout the U.S., Canada, and rings are not field replaceable. A the riser and slow the operation of the internationally, through a network of Dry Pipe Valve with damaged seat valve. Such water columning above Central Sprinkler sales and rings must be replaced. The seat the clapper may result in valve distribution centers. You may write rings should be inspected at any time malfunctioning and possible freezing directly to Central Sprinkler Company there is excessive water leakage at of water in the riser. The Condensate or call 215-362-0700 for the center the Automatic Ball Drip Valve. Drain Valve (#40) is utilized to check nearest you. the priming water level (see Setting Automatic Ball Drip Valve Procedure, steps 10 through 12). Guarantee: Central Sprinkler (Refer to Figure 5) The plunger on The priming water level should be Company will repair and/or replace the Ball Drip Valve (#32) should be checked at least quarterly. any products found to be defective in pushed in during inspection to verify material or workmanship within a that the ball is free and any slight Periodic Testing period of one year from the date of seepage of water from the intermedi- A Main Drain Test and Alarm Test shipment. Please refer to the current ate chamber of the Dry Pipe Valve should be performed on a quarterly price list for further details of the has escaped. Excessive seepage basis. A Trip Test should be warranty. indicates the rubber seal on the valve performed on an annual basis. clapper should be replaced. When the system is placed back in Patents: Patents are pending. service after any maintenance, notify Gauges all Authorities Having Jurisdiction, Conversion table: (Refer to Figure 5) The air (#41) and and the personnel who were affected 1 inch = 25.4 mm water (#42) pressure gauges should during system shutdown. 1 foot = 0.3040 M be checked for accuracy. Verify that 1 pound = 0.4536 kg the required air pressure is being 1 foot pound = 1.36 Nm applied to the system. If the gauges 1 p.s.i. = 6.895 Kpa are damaged or non-operational, they = 0.0689 bar should be replaced. = 0.0703 kg/cm2 1 U.S. gallon = 3.785 dm3 Accessory Devices = 3.785 liters The Air Maintenance Device, Accelerator and Anti-Flooding Device, Conversions are approximate. Pressure Alarm Switch and Water Motor Alarm should be inspected and maintained in accordance with the instructions in the appropriate Central Bulletin and NFPA 25A.