Asme Relief Valve Orifice Size Chart

How to useHow to use. Part 2, Sizing, provides the information you need to choose the correct valve orifice area. This catalog simplifies the sizing and selection of Series 2600 process pressure relief valves. MERCER VALVE COMPANY, INC. of pressure relief valves is very important. Learn More. 2, 3/10/09 3 PURPOSE This Guide provides information for the proper application of the ASME B31. Pop-acting relief valves do not immediately open completely (to 100% lift). Series 740 safety and relief valve is designed for accuracy and reliability. Orifice area was chosen as per the ASME section VIII guidance( D,E,L,M)The orifice area for L = 2. understanding of relief valve sizing calculations. Pressure Safety Valve PSV Sizing Fire Case Liquid Filled Vessel PSV Sizing Fire Case Gas/Vapor Filled Vessel. Capacity data based on a maximum back pressure of 10%. There is a spill loop with an orifice plate, and the requirement is that the orifice. 4 Aquatrol • Safety Relief Valves SIZES FROM ½" TO 2" LIQUID/AIR/GAS RATED TO 750 PSI STEAM TO 300 PSI TEMPERATURES FROM-320°F TO 800°F Aquatrol's new Series 740 safety and relief valve is designed for accuracy and reliability.



The two standard pressure tapping arrangements for small bore orifices are shown in the drawings; the location of the pressure taps affects the discharge coefficient somewhat. I am trying to figure out how to calculate the diameter of an orifice for a pill loop in an oil heater and pump. The solution should entail the most economical and safe, reliable, long-term operation. 1 Normative references 6 2. Browse Item # 6131M4Y in the Circle Valve Technologies Inc. Contractorsunlimited. 04 2 229 347 503 5 338 512 742 10 415 630 912 15 426 646 936 20 426 646 936 29 426 646 936 Note 1. In 1996, Watts moved the manufacturing responsibility for safety valves to the Spence Engineering in Walden, New York. Multiple purpose safety and relief valve for all services: Liquid, Steam and Air/Gas. Pressure-relief valves (PRVs) or rupture disks (RDs) may be used independently or in combination with each other to provide the required protection against excessive pressure accumulation. Pressure Relief Valve Selection Chart. API Standard 520 - Sizing, Selection, & Installation of Pressure Relieving Devices Part I, Sizing & Selection Last update: June 16, 2005 520 Part I 7th - Jan. of pressure relief valves is very important. The ASME Boiler and Pressure Vessel Code and publications by many manufacturers caution the design engineer to consider back pressure in discharge piping when sizing and selecting pressure relief valves. Pressure relief valves are selected on the basis of their ability to meet an expected relieving condition and flowing a sufficient amount of fluid to prevent excessive pres-sure increase. Mercer Valve's Auto Seat Technology® has made the 9100 Series. See Safety & Relief Valve Catalog (SRCA9000) for more detailed information about the products in this section. 527, API RP 576.



The software aims to provide a productive environment for all users. 0012 100 psig Article No. Codes: ASME I, VIII and PED Model 6254: As model 6252 except certified for ASME code section IV - low pressure steam heating boilers. 4 mm; Welding of tab Tab may be integral with orifice plate up to and including 7 mm plate thickness. Safety relief valve innovations from the product line include the Thermodisc® temperature compensating disc and the first modular pilot-operated valve. Anderson Greenwood, Crosby and Varec ProductsPreliminary Edition, March 2012. Pop-acting relief valves do not immediately open completely (to 100% lift). New, never used Canalta Senior with CPA TBR Pin type flow conditioner. Pressure Safety Valve PSV Sizing Fire Case Liquid Filled Vessel PSV Sizing Fire Case Gas/Vapor Filled Vessel. may exist in the system into which the safety relief valve discharges. Then, refer to the capacity tables, or use the proper formula, to solve for the required effective orifice area. The PROTEGO ® Type PM-HF pilot-controlled diaphragm valve is a highly developed valve for pressure and vacuum relief. Note: if the intersection of the Venting Capacity, (CFM) and Operating Pressure (PSi) lies between orifice curve, use the larger orifice. The black line is the relief valve opening. All products meet ISO 9001 and ISO 14001 standards, which define the requirements for quality management systems and environmental management systems, respectively. Valve Orifice Size in. Selection Criteria Pressure Build-up Some direct-operated relief valves require significant pressure build-up to achieve maximum capacity. 0 barg) only.



The first step is to determine whether the gas flow type is critical or sub-critical. mm Class 1905 1. The seat rings are steel and makeup part of the valve trim. Engineered for heavy-duty industrial usage. Correct and comprehensive pressure relief valve sizing is a complex multi-step process that should follow the following stepwise approach: 1. 16) is equipped with a Low Pressure Shut-off Valve and Internal. 6402 9100 Series Model 20 Product Numbering System VALVE SERIES 91 – 9100 Series INLET & OUTLET COMBINATION (See Selection Table Page 4) ORIFICE SIZE C or D INLET BASE & BODY MATERIAL FLANGED 1 – RF x RF / CARBON. 3 backpressure The pressure that exists at the outlet of a pressure relief device as a result of the pressure in the discharge system. 375* *asme uv coded per sec, div. The chart below provides ratings based on valve size and type. com The American Petroleum Institute has developed a series of inlet size, orifice, outlet size combinations for various pressure classes of flanged relief valves. FLOW SAFE introduces new high pressure small orifice ASME certified relief! FLOW SAFE is proud to offer our new Dual Outlet Pilot Operated Safety Relief Valves! FLOW SAFE is proud to be the only SRV manufacturer to offer a standard 3 year limited product warranty!. SERIES 8200/8300 SAFETY RELIEF VALVES Taylor Valve 8200/8300 Safety Relief Valves are engineered and manufactured to the highest standards and feature a "state-of-the-art" soft seat which gives you a bubble-tight seal for hundreds of "pops". These valves are for general purpose gas and air services, and are recommended for over-pressure protection on separators, compressors, pressure vessels, heater-treaters, gathering and transmission lines, meter runs and other systems where the rated capacities of the valve are commensurate with the requirements of the system. Pentair Pressure Relief Valve Engineering Handbook Chapter 4 – Design Fundamentals Technical Publication No.



825 Valve Type Inlet Outlet Size ANSI Std. Orifice Letter Inlet Size (in. The valve shall have a Teflon(r) seat and conform to API 527. It is specially designed to withstand high pressures and abrasive slurries – some of the toughest services in mining, (including oil sands processing), steel, power, chemical, municipal sludge, bio-fuels production, and paper industries. • Swagelok proportional relief valves should never be used as ASME Boiler and Pressure Vessel Code safety relief devices. But, the final sizing must be done using the ASME orifice size and coefficient - API 520 Pt 2 clearly states that. A minimal working pressure of 0. Flange Maximum Temperature1 Discharge area Designation Size Class Size Class 750°F (399°C) 1000°F in. Circle Seal D500 and M5100 ASME Relief Valves. Size a gas/liquid orifice plate using ISO5167 (2003) International standard and Crane's Flow of Fluids through Valves equation 3. We also sell parts and remanufactured valves. asme section viii air/gas and cryogenic, uv national board certified safety valve uv national board certified safety valve valve size size cd eorifice orifice. A pilot operated pressure relief valve is a pressure relief valve in which the major relieving device. Exposed-spring. KUNKLE SAFETY AND RELIEF PRODUCTS IEEHNIEAL REFERENCE ASME Codes - Requirements National Board Kunkle valves are manufactured at facilities that meet the manufacturing requirements of the ASME Sections 1, IV, and VIII codes for pressure relief valves. Actuator and valve are adapted per-fectly to each other with closed design and. This article lists the standard effective orifice areas for the orifice designations found in API RP 526 5th edition. Both products have a proven track record for performance, versatility and ease of maintenance.



However, the differences in capacity between the initial choice of API orifice and the actual ASME orifice can be significant. 801 for steam/gas and 0. The valve opening. The liquid trim guide for the RL Series must be adjusted in order to meet the ASME Code Section VIII performance criteria. ASME approved and National Board flow-rated for capacity. The FLOW SAFE F7000/8000 Series Pilot Operated Safety Relief Valves, with accurate operational characteristics, are engineered to provide superior performance for today's industries. Diameter and Lengths of the stud and bolt are covered in flange standard ASME B16. relief valves, APIStandard 526 states that for an orifice size of F and smaller, the maximum allowable leakage rate is 40 bubbles / minute (approximately 6 cubic feet per 24 hours). 11 most important questions & answers from ASME B 31. SAFETY VALVES SIZES FROM 1/2" TO 2 1/2" RATED TO 300 PSI TEMPERATURES TO 425°F Aquatrol's Series 560/570 valve line is a high capacity safety valve used for boilers, piping lines and vessel protection. Bảng giá Yokogawa, wika, versa, united electric, agco, allen bradlley, alco, ashcroft, bartec, nogren, sor, asia Vietnam_ANS Vietnam. Finding the Actual Orfice Area for a Type F:. To find the gas flow equivalent to the air flow given in the above chart, divide the chart flow by the appropriate factor above. mercervalve. Back pressure The pressure that exists at the outlet of a pressure relief device as a result of the pressure in the discharge system. parameters as pressure relief valve orifice area and maximum available flow.



P line is the line pressure of the system, which is regulated using the pressure relief valve. The flagship of our H-Series line encompasses high-end features and construction materials as standard. Orifice area was chosen as per the ASME section VIII guidance( D,E,L,M)The orifice area for L = 2. This means that the size of the valve orifices must be calculated taking the required flow, lading fluid. 4 mm) in a complete range of ASME-certified orifice sizes • Meets industry specifications. The safety valve is rated by the American Society of Mechanical Engineers (ASME) with a UV mark for pressure vessel safety. 5- flanging, API Std. When a vendor sizes a valve for you, they are doing a final sizing calculation. Pressure Relief Valve Sizing Craig Spears November 10, 2015. See Safety & Relief Valve Catalog (SRCA9000) for more detailed information about the products in this section. 17, 2011 19000 Standard Valves The 19000 Series threaded safety relief valve has 316 stainless steel trim as standard material. GE's Consolidated 11000 Series Safety Relief Valve is a certified ASME Section VIII, Division 1 valve Orifice Capacity Chart ORIFICE SIZE SRV SERIES S. Do not use a pipe wrench! Use proper type and size wrench on wrench pads only. Aquatrol’s new Series 740 safety and relief valve is designed for accuracy and reliability. 8 150 1910 1.



Although relief devices may never be activated, they must be designed and sized to function correctly every time they are necessary. What is a spectacle blind flange? valve in that the blind is a permanent or long term isolation device. 2 150 1912 2. 650 ASME Coefficients of Discharge Use De-rated Value (K) for sizing Varies from Manufacturer to. 783 SCFM Air/PSIA at 110% of set pressure. 2 safety 3. The flow capacity chart of the relief valve is seen below, which shows a 15 SCFM capacity at a 20. They are pressed into the valve body and wedged into place, forming a seal with the body. Cylinder Valves Cylinder Valves - Vapor Service - No Relief Choose either Standard or MultiBonnet versions. Circle Seal D500 and M5100 ASME Relief Valves. 2600 Series Metallurgy Integral Sleeve Guide The Farris pressure relief valve design incorporates an integral sleeve guide (Fig 5), assuring continual positive alignment after the part has been manufactured, and including the same high corrosion resistant properties in the guide flange that are present in the sleeve portion of the guide. 2 Clean the end connections and mating pipe prior to valve installation. 3 Process Piping Guide Rev. Valve Sizing Technical Bulletin Scope Valve size often is described by the nominal size of the end connections, but a more important measure is the flow that the valve can provide. To open large orifices while keeping solenoid size small, a Pilot Operated construction is used. How do I obtain flow capacities for ASME safety valves? The flow capacity charts for all of our safety valves are shown under the Products, ASME Safety Valve section of our web page. The valve shall contain two safety relief valves, two rupture discs and two bleed valves. These valves are for general purpose gas and air services, and are recommended for over-pressure protection on separators, compressors, pressure vessels, heater-treaters, gathering and transmission lines, meter runs and other systems where the rated capacities of the valve are commensurate with the requirements of the system. They were developed to facilitate choosing a relief valve size early in a project and to ensure that the relief valve finally purchased will have a certified capacity that meets or exceeds the required relief capacity.



(2) Outlet connections do not apply for **AT top outlet valve. * ASME certified slopes determined by actual tests conducted at the National Board Testing. The valve, manufactured over the years by companies like Garrett, USI and Axelson, is now manufactured and sold by NuFlo Measurement Systems under the Axelson brand. The valves are specified for transmission pipelines, pumping, compression and reinjection units, offshore platforms, onshore terminals, pig traps, measuring stations, and surge-relief skids. Balanced Pressure Relief Valve:Aspring-loaded pressure relief valve that incorporates a means for minimizing the effect of back pressure on the performance characteristics. codes and standards. However, is that all there all there is to know ANSI Classes for Valves? The answer is, "No. The maximum flow through this actual orifice will be the valve's capacity. What is the difference between a safety valve and a relief valve? Control Devices offers two standard types of pressure relief devices for air. The discharge coefficient is a dimensionless number used to characterise the flow and pressure loss behaviour of nozzles and orifices in fluid systems. This means that the size of the valve orifices must be calculated taking the required flow, lading fluid. Some manufacturers can offer full-bore POSRVs where a larger orifice can be obtained in a smaller size valve by increasing the curtain area. 1 The LP-Gas Serviceman's Manual RegO®, has prepared this LP-Gas Serviceman's Manual for use by installation servicemen and others requiring a handy reference for field service work. If in our opinion the valve is defective it will be repaired or replaced F. Choked flow in liquids. Dante Valve Discusses Aircraft Carrier Budget Priorities on Two Day Lobbying Trip to Capitol Hill We are a family-owned leading international manufacturer and distributor of valves and related products for the industrial and military markets. 6402 valve size and flange rating inlet x outlet available orifice size inlet-outlet code pressure range (psig) c. Our type numbering system simplifies the selection and specifying of Farris pressure relief valves because the digits that comprise a specific type number have a distinct significance. The proper orifice size code can be garnered from a manufacturer's capacity table.



Designed and engineered for heavy-duty industrial use. Application of color Doppler flow mapping to calculate orifice area of St Jude mitral valve. series 570 capacities • air/gas • asme section viii section viii (uv)-national board certified c a p a c i t i e s orifice d orifice e orifice f orifice g orifice h orifice j set pressure psi. Orifice Sizes: Orifice diameters range from. Pressure-relief valves (PRVs) or rupture disks (RDs) may be used independently or in combination with each other to provide the required protection against excessive pressure accumulation. back-up Internal Relief Valve (R) and a Vent (V) hole in the sliding orifice. See Safety & Relief Valve Catalog (SRCA9000) for more detailed information about the products in this section. 783 SCFM Air/PSIA at 110% of set pressure. Pressure relief valves with a restricted lift option are also a cost effective solution. Safety valves A safety valve shows a quick opening of the disc achieved through particular devices which increase the area of pressure on the disc with the. - the ASME flange class, followed by RF - the nominal pipe size (NPS) - the measured orifice D1 (in mm) - the material of the orifice plate - the type of orifice plate (Square, Restriction etc. IHS Markit is your source for ASME standards and publications. (In critical service, some operators require a backup relief valve or rupture disc to the primary relief device to increase reliability or to provide a spare). Normal conditions are moderate part contamination, media. A bleed ring can be used instead of an orifice flange union. Note: Available factory preset at any pressure 15-250 psig. Relief valves are designed to open at a preset pressure (or temperature) level and relieve the system when it has exceeded the desired level. 2-Phase API 520, Part I, 6th Edition: Separated Flow Method Orifice Area and Flow Calculations; Tank Blanketing, Back Pressure or Pressure Reducing Regulator Sizing; Varec Flame Arrester Sizing; Yarway ARC Flow Control Valve Sizing; Tank Vent Sizing for Pressure Relief Valve (API 200/ISO 28300) or Free Vent (API 2000/ ISO 28300, 6th edition) Sizing. Knowing the required relief valve orifice size, an actual orifice size equal to or greater than the calculated orifice size is chosen from a the standard range.



Standard API 526 Orifice Sizing (Actual Size) D. When a vendor sizes a valve for you, they are doing a final sizing calculation. A typical Tri-Clamp® connection consists of two Tri-Clamp® flanges or ferrules, a Tri-Clamp® gasket, and one of several types of clamps. B31RAS–The B31RAS (pg. SV5601 & 5708 Series Bronze Safety Valves ASME Section I & VIII - NB Certified for Air, Gas and Steam TI-3-215-US 12. Size a gas/liquid orifice plate using ISO5167 (2003) International standard and Crane's Flow of Fluids through Valves equation 3. The discharge coefficient is a dimensionless number used to characterise the flow and pressure loss behaviour of nozzles and orifices in fluid systems. asme section viii air/gas and cryogenic, uv national board certified safety valve uv national board certified safety valve valve size size cd eorifice orifice. Side Venting. The system designer and user must determine when such codes apply and whether these relief valves conform to them. DSOPRV AGC POPRV API & ASME KA Values API Preliminary Sizing ASME Models Actual Valve Performance API Uses API 526 Standard Orifice Areas ASME Uses NB-18 Actual Certified Orifice Areas API Coefficients of Discharge Gas / Vapor = 0. Orifice: C and D Mercer Safety Relief / Valve Mediums: Air, gas and liquid. However, the differences in capacity between the initial choice of API orifice and the actual ASME orifice can be significant. In addition, it meets with domestic and foreign regulations such as technical standard for thermal power generation and CE mark. 3 Sizing the valve is based on ensuring that the steam flows through the orifice into an. Many SRVs are installed close to reciprocating compressors. 00-2 AUGUST 2014 www. 1 Terms and definitions 7 3. The valve shall have dual blowdown ring to allow better adjustment of the pop and blowdown. It takes into account all leading global standards and codes.



Safety valves and pressure relief valves protect vessels, piping systems, and equipment from overpressure, which, if unchecked, can not only damage a system but potentially cause an explosion. Large orifice valves should be used, as restrictive valve paths can cause fractionization of the sampled gas. SPENCE/KUNKLE COMPETITIVE CROSSOVER CHART WHY CHOOSE SPENCE SAFETY AND RELIEF VALVES? 1) Spence Engineering sets and tests all valves in accordance with the applicable ASME code and API 527. GE’s Consolidated 11000 Series Safety Relief Valve is a certified ASME Section VIII, Division 1 valve Orifice Capacity Chart ORIFICE SIZE SRV SERIES S. These valves are available in 1/2", 3/4" and 1" inlet sizes with a 1" outlet and two orifice areas. A minimal working pressure of 0. The flow capacity chart of the relief valve is seen below, which shows a 64 SCFM capacity at a 100 psi setting. as you are going to use bolt and stud to connect flanges. This article follows up with an introduction to sizing pressure-relief devices to ensure that they function properly. 7 SCFM Air/PSIA at 120% of set pressure. It shall be “V” or “UV” National Board Certified. Designed and engineered for heavy-duty industrial use. A relief device's overpressure is the pressure increase over its set pressure, usually expressed as a percentage of the set pressure. Optional 1/8", 1/4", and 5/16" orifice nozzles are also available. The pilot-operated pressure relief valve has a highly complicated structure, and its design and production should be thoroughly studied. 8 to calculate the minimum required orifice area for a safety valve used on steam. This unique design was developed especially for the emerging CNG and other high pressure applications. Reliable performance and easy maintenance procedures are characteristics of this valve (when properly installed in suitable applications for its design). ) ASME Orifi ce Area in 20.



If the fluid is a liquid, a different type of limiting condition (also known as choked flow) occurs when the Venturi effect acting on the liquid flow through the restriction causes a decrease of the liquid pressure beyond the restriction to below that of the liquid's vapor pressure at the prevailing liquid temperature. The cover bearing and seat in the 6” and smaller size valve shall be threaded into the cover and body. Pressure Relief Valve Application. Quantity Nominal valve size (inlet x orifice x outlet) Valve style Inlet connection rating and facing Outlet connection rating and facing Service (liquid, gas or vapor) Set pressure (psig) Back pressure (psig) if any, and whether constant or variable Maximum service temperature (°F) Cap or lifting lever type Valve materials Seat material Code. The main valve seat and stem bearing in the valve cover shall be removable. The valve will operate at pressures from 0 psi to its rated maximum. Any valve claimed to be defective may be returned to us, on receipt of our written consent, for examination. Flow-Tek Series FT-500 relief valves are intended for ASME section VIII steam service application and are furnished with a regular lifting lever and open cap as standard. • Some system applications require relief valves to meet specific safety codes. Based on 10% accumulation. Now nearing its ninth decade, Conbraco Industries, Inc. (f) Fluorine. , for environmental reasons. Relief Valve Capacity Ratings: (Pounds per minute) - Henry Relief valves are constructed and marked in accordance with the requirements of the ASME (Boiler and Pressure Vessel Code Section VIII, Division 1). B&G ASME safety relief valves are available in a wide range of capacities to closely match the BTUH output range of hot water heating boilers, direct fired hot water heaters. Pressure-relief valves and rupture discs will always work because of the high reliability of their design. 375* *asme uv coded per sec, div.



Internal Pilot Operated Valves. (uv) rating-90% of actual capacity at 10% accumulation capacity in pounds of saturated steam per hour asme section viii-pressure vessel 19 series bronze safety valves air capacity chart - pressure vessel code. Limiting conditions refer to standard connections only. Size a gas/liquid orifice plate using ISO5167 (2003) International standard and Crane's Flow of Fluids through Valves equation 3. 7 SCFM Air/PSIA at 120% of set pressure. safety relief valve issued - april 2000 cavmc-0515-us-0208 iso 9001 certified cash valve type c-776. Read COSR0023_SRCA9000 text version. PRESSURE SAFETY VALVE MANUFACTURE CROSBY Series JOS-E, JBS-E, JLT-JOS-E, JLT-JBS-E, JOS-HE Size: 1D2 thru 8 "T2 10" Provide overpressure protection of high-quality applications for air, gas, steam, vapor, liquid and two-phase in the standard design. Relief, Backpressure, Bypass & Anti-Siphon Valves. Failure to properly inspect and maintain pressure relief valves could result in personal injuries or property damage. ASME approved and National Board flow-rated for capacity. The Crosby® Pressure Relief Valve Engineering Hand- book contains important technical information relating to pressure relief valves. Pioneers in Fluid Power Established in 1912, FULFLO was incorporated in 1933 under its present name and trademark. The 2700 series process valve features a metal seat with optional o-ring and both flanged and balanced design options. PM-HF Pressure/Vacuum Relief Valve Pilot-operated diaphragm valve Function and Description.



New, never used Canalta Senior with CPA TBR Pin type flow conditioner. the basic valve series, materials of construction, connection type, boiler code con-formance, inlet and outlet connections, orifice size and set pressure. 1 Terms and definitions 7 3. Parker Community. Tyco Pressure Relief Valve Engineering Handbook. 9 inches only (arriving dia from Pi/4*d2 = 2. I have listed two methods there, but regardless of which method you used, the capacity was based on an orifice calculation similar to a relief valve. Most competitive valves do not meet API 527, leading to premature simmering and leakage causing system problems and premature valve failure. Under no circumstances should there be a flow restriction or valve of any type between the safety valve and pressure vessel. The allowable over pressure can vary from 10% to 21% on unfired vessels and systems, depending on the sizing basis, number of valves, and whether a fire condition is encountered. 1% Drum SV’s. IHS Markit is your source for ASME standards and publications. Cylinder Valves Cylinder Valves - Vapor Service - No Relief Choose either Standard or MultiBonnet versions. And determining flow through a valve can be simple. catalog including Item #,Body Material,List Price,End Connection 1 Type,End Connection 1 Size,End Connection 2 Size,End Connection 2 Type,Cracking Pressure,Flow Coefficient (Cv),Max. relief valves including the latest information available to assist you in the sizing and selection of the proper valves for your application. The system designer and user must determine when such codes apply and whether these relief valves conform to them.



Safety Relief Valves ASME Section VIII - NB Certified for Liquid, Air/Gas and Steam Series 740 Brass, bronze construction with stainless steel ring, seat (disk) and springs. Multiple purpose pressure relief valve for all services: Liquid, Steam and Air/Gas. • Steam or Air Service The valve is designed for all steam and air service applications that. T&P and ASME Safety Relief Valves watts. For additional information on inlet piping or its effect on relief valve performance, see Reindl & Jekel (2006). 175 Sch 160 pipe and pipe nipples shall be used for threaded connections for sizes NPS ½ through NPS 1-1/2. SEAT RINGS. The size of a relief valve should be checked for the following conditions. The discharge coefficient is a dimensionless number used to characterise the flow and pressure loss behaviour of nozzles and orifices in fluid systems. Relief device basics The purpose of relief sizing is to determine the proper discharge area of the relief device and diameter of the asso-. About Apollo Valves: Conbraco Industries was created when two Detroit-based manufacturers of brass valves and fittings merged in 1928 forming Consolidated Brass Company. (2) Outlet connections do not apply for **AT top outlet valve. Pressure relief valves are used to protect equipment from excessive overpressure. Relief Set Valve Inlet and Outlet Size (in, HG) 2" 21/2" 3" Orifice Area, in 2 1. 11 dimensions. This valve must be mounted in a vertical upright position directly to a clean tapped opening in the top of the pressure vessel. And determining flow through a valve can be simple. 170 These items should be qualified for use in this specification in accordance with ASME B31. Pressure Safety-Relief Valves: API and ASME Confusion When a valve manufacturer gets the UV code stamp that certifies the valve orifice size if one simply selects the ASME data set, the N. Any backpressure applied to the downstream side of the valve will result in improper pressure relief. Asme Relief Valve Orifice Size Chart.