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Emerson Steam University Virtual Series Emerson Steam University Virtual Series A Practical Approach To Understanding Steam Systems Day 3 – Pressure Relief for Steam Generation & Pressure Reduction Applications R.E. Mason Confidential and Proprietary/For internal use only Safety Moment: Selfie Safety Emerson Steam University Virtual Series Housekeeping • Today’s webinar is scheduled to last 1.5 hrs including Q&A • All participants will be muted to enable the speakers to present without interruption • Questions can be submitted via the GoToWebinar Questions Panel at any time • A link to slides & recordings will be emailed 72 hours after the last session in this series has concluded Wednesday, June 2 • Complete polls & surveys to mark attendance for PDH credits. Total PDH credits for today’s session: 1.5 (Live Session ONLY) • Tell us how we did by completing the survey The survey will launch after this session Emerson Steam University Virtual Series Agenda At-A-Glance Day Topic Length Presenter & Facilitator Kyle Richard Introduction to Steam Systems 1 HR 1 Rick Vance Rick Vance Steam Trap Fundamentals and Testing 1 HR 2 Brett Easterling Dean Barnes Pressure Relief for Steam Generation 1 HR Carl Sitler 3 Jeff Welch Pressure Reduction Applications 30 MIN Carl Sitler Brad Emry Control Valve & Steam Conditioning Applications 30 MIN Kyle Richard 4 Leif Rickles Isolation Valve Applications 30 MIN Kyle Richard Boiler Feedwater 30 MIN Tim Dwyer Boiler Level Monitoring 20 MIN 5 Rick Vance ARC Valve 10 MIN Session Agenda 1 Pressure Relief for Steam Generation Dean Barnes 2 Break 3 Pressure Reduction Applications Jeff Welch 4 Q&A Emerson Steam University Virtual Series Meet Our Experts Dean Barnes US Southeast Area Growth Manager Speaker Image Emerson Working with Pressure Relief Valve products for over 30 years. Started with Anderson Greenwood in 1991, working in many roles in PRV technical sales and applications. I have worked in the SE region for the past 17 years, reporting directly to the Emerson Stafford, TX manufacturing facility. Prior to starting my career with AG, I served six years in the US Navy as a Boiler Technician second class PO. Received business administration degree from Faulkner University in 1996. [email protected] Emerson Steam University Virtual Series Pressure Relief for Steam Generation Dean Barnes Emerson Emerson Steam University Virtual Series Pressure Relief Introduction • The purpose of Pressure Relief Valves is to protect personnel and property. • Pressure Relief devices are the last line of defense against catastrophic overpressure events. • Pressure Relief Valves (PRVs) are used for primary overpressure protection of systems containing tanks, vessels, piping, etc. • The specifications for overpressure protection are typically determined by various codes or regulations that outline the requirements for pressure-containing systems which include pressure relief devices. • The three most referenced organizations are the American Society of Mechanical Engineers (ASME), the American Petroleum Institute (API) and the National Board of Boiler Inspectors (NBBI & NBIC). How do ASME, NBBI, NBIC and API work together? ASME Provides rules for PRV construction/testing Describes required design elements Describes Capacity certification process Requirements for use of Code symbols NBBI NBIC Enforces ASME Code Provides rules for PRV repair Provides Capacity Certifications Refers to original Code of construction (ASME) Writes NBIC Refers to ASME for test requirements Certifies UV/V/VR stamp holders NBBI provides “third party inspection” API Provides standardization of product Provides methodology for sizing/selection Provides seat tightness standards Emerson Pressure Relief Overview Industries Served . Capabilities . Process: Refining, Chemical, Petrochemical, • Engineered solutions Pulp & Paper • Applications expertise . Oil & Gas: Upstream Onshore and Offshore, • Global codes and regulations coverage Midstream, Downstream • Product sizing and selection tools including PRV2Size . Power: Conventional, Nuclear, Renewables . Comprehensive Product Portfolio Common Overpressure Protection Scenarios • Direct spring pressure relief valves • High and low pressure pilot operated relief Blocked valves Discharges & Thermal Runaway External Expansion Reactions Fire Overfilling • Electro Pneumatic Relief Valves, safety selector valves, and rupture discs . Global Reach • Global manufacturing and distribution locations • QuickShip and Service Centers Overpressure Protection Overview • What is Overpressure Protection? Any method of controlled discharging (venting) the fluid (liquids and/or vapors) from a system to atmosphere or to some other system, so that the pressure will not exceed the specified safe value Accident Investigations Properly sized and maintained pressure relief valve will allow for a controlled discharge Emerson Confidential 12 Pressure Relief Overview - Codes and Standards • ASME Boiler and Pressure Vessel Code Section I – Power Boilers o “V” Stamp V o Governing rules for construction of Power Boilers with MAWP of greater than 15 psig o Safety Valves and Safety Relief Valves PG 67- PG 73 Section IV – Low Pressure Steam & Hot Water / Low Temperature Boilers o Governing boilers intended for steam at pressures of 15 psi or heating boilers intended for pressures up to160 psig and temperatures up to 250°F HV Section VIII – Pressure Vessels o “UV” Stamp o Governing rules for pressure vessels with MAWP of 15 psig or greater o Pressure Relief Devices UG 125- UG 137 UV • The National Board o Certifies valve capacity and verifies valve compliance with the ASME code o ASME does not certify or approve any device ASME Code Section I - Overpressure Protection Requirements • Boilers in which steam or vapor is generated at a pressure of > 15psig . High-temperature water boilers intended for operation at pressures >160 psig and or temperatures > 250°F • Safety Valves & Safety Relief Valves PG-67 Boiler / Safety Valve Requirements PG-68 Superheater and Reheater / Safety Valve Requirements PG-69 Certification of Capacity of Pressure Relief Valves PG-70 Capacity of Safety Valves PG-71 Mounting of Pressure Relief Valves PG-72 Operation of Pressure Relief Valves o Designed to operate without chattering, full lift at 3% overpressure PG-73 Minimum Requirements for Pressure Relief Valves o Supplied with lifting device (lever), seat/body arrangement, body drain below seat level, sealed adjustment ring settings and set point Case: o 2254 Changeover valves installed between safety valves and boilers . Permitted when boiler MAWP does not exceed 800 psi and maximum temperature of 800°F Where are Pressure Relief Valves Typically Installed on a Boiler? Economizer Typical Super Critical Boiler Unit Tubular heat transfer system to preheat boiler feedwater with thermal energy extracted from the flue gas Steam Drum Pressure chamber located at upper extremity of a boiler circulatory system in which steam generated in the boiler is separated from the water Superheater A bank of tubes located within the boiler which receives saturated steam directly from the steam drum and heats this saturated steam above saturation point Reheater (Hot and Cold) Piping from (Cold) and to (Hot) the turbine HP and IP sections being used to reheat and utilize residual steam. Basic Section I Sizing Rules Basic Section I Sizing Rules - Low set drum valve set at design pressure - Other valves shall have staggered settings - Not permitted to rise more than 6% above MAWP, taking into account 3% accumulation All valves open/full flowing 106% Low Set Drum Valve open/full flowing (High Set Drum Valve set pressure) 103% Design Pressure (MAWP) (Low Set Drum Valve set pressure) 100% Spring Operated Valves (ASME Section I) • Section 1 control ring settings Raising the upper ring (guide ring) will decrease (shorten) blowdown Raising the lower ring (nozzle ring) will decrease (reduce) simmer Lowering the upper ring will increase (lengthen) blowdown Lowering the lower ring will increase simmer Boiler Set Sizing Total Relieving Capacity of all Code valves must be equal to or greater than the RHO maximum continuous rating of the boiler(Drum & SHO) or reheater (RHO & RHI). SHO Drum Steam Drum Valves must RHI relieve a minimum of 75% of boiler capacity. Superheater safety can take a maximum of 25% of boiler capacity. Pressure Relief Overview – API Codes and Standards • API Recommended Practices (RP) and Standards (STD) STD 521 – Petroleum and Natural Gas Industries – Pressure Relieving and Depressuring Systems o Highlights causes and prevention of overpressure o Determination of individual relieving rates o Selection and design of disposal systems STD 520 Part 1 – Sizing and Selection of Pressure Relieving Devices in Refineries o Sizing equations – Gas/Vapor, Liquids, Steam, Two-phase, Rupture Disc o Determination relief requirement (capacity) o Backpressure, relieving pressure, API Effective Area and Effective Coefficient of Discharge STD 520 Part II – Installation of Pressure Relieving Devices in Refineries o Inlet and Discharge piping o Isolation valves in piping o PRV location and positioning Pressure Relief Overview – API Codes and Standards • API Recommended Practices (RP) and Standards (STD) continued STD 526 – Flanged Steel Pressure Relief Valves o Industry standards for dimensions, pressure/temperature ratings o Maximum set pressures by orifice size/body materials o Spring loaded and piloted valves STD 527 – Seat Tightness of Pressure Relief Valves o Permissible leakage rate of conventional,
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