Pressure & Flame Protection

Transcription

1 Pressure & Flame Protection Safety Relief Valves

2 Safety Relief Valves WB SERIES SPRING LOADED SAFETY RELIEF VALVES The WB is designed safely relieve excess pressure in pumps, pipework, tanks, calorifiers, gas and oil separars and other process vessels. It is suitable for gas, steam, vapour and liquid applications. The WB conforms API 526 pressure/temperature ranges, orifice areas and dimensions. SAFEFLO SAFETY AND THERMAL RELIEF VALVES Safeflo valves are designed for similar duties the WB but for small capacity applications.they safely relieve thermal expansion of process fluids in vessels and long lengths of pipework, and are suitable for gas and liquid applications. SAFESET PILOT OPERATED SAFETY RELIEF VALVES Safeset valves are self contained pilot operated safety relief valves which use the system pressure control the valve opening and closing. No other source of energy is required. A choice of different types of Safeset pilot valves are available, including pop and modulating action suit a variety of applications. 1 Safeset valves conform API 526 pilot operated pressure/temperature ranges and dimensions, with multiple orifice areas contained within each valve body size.

3 CONTENTS Page Birkett Range 3 Introduction 4 International approvals and authorisations 5 WB Series 6 Features and benefits 7-10 Valve types and action Drawings Accessories 17 Figure numbering system 18 Material temperature ranges Valve selection charts, D T Valve adjustment Seat tightness/seat leakage testing Page Sizing Sizing formula 83 Nomenclature 84 Back pressure/blowdown limits and orifice areas Sizing facrs Capacity charts 97 Reaction forces 98 Definitions 98 Definitions of terms 99 Operational characteristics 100 Pressure term relationships 51 Safeflo 52 Features and benefits Drawings 55 Accessories 56 Figure numbering system Dimensions 59 Safeset 60 Features and benefits 61 Dual Outlet/Full Bore Pilot Valve 62 Pilot types and basic operation Type 2 - Pop Action Pilot Type 4 and 8 - Modulating Action Pilot 69 Technical specification Drawings and materials of construction Accessories 76 Figure numbering system Dimensions Operating pressure/temperature limits 2

4 Safety Relief Valves INTRODUCTION The effects of exceeding safe pressure levels in an unprotected pressure vessel or system can have catastrophic effects on both plant and personnel. Safety relief valves should be used protect any pressurised system from the effects of exceeding its design pressure limit. A safety relief valve is designed aumatically discharge gas, steam, vapour or liquid from any pressure containing system, preventing a predetermined safe pressure being exceeded, and protecting plant and personnel. The Birkett range of safety relief valves contains three distinct valve types: WB Series spring loaded safety relief valves. Safeflo safety and thermal relief valves. Safeset pilot operated safety relief valves. All types are certified in accordance with ASME Code Section VIII. All Birkett valves are available through our global agent distribution network supported by our own regional sales offices around the world. 3

5 INTERNATIONAL APPROVALS AND AUTHORISATIONS Our approvals and accreditations include ISO 9001:2008, ASME, Chinese Safety Quality Licence, TUV, Bureau Veritas, Somwezen, PED, ATEX and GOST-R. APPLICABLE STANDARDS ISO 9001:2008 Quality Standard ASME Code Section VIII All valves are UV certified API 520 : Part 1 Sizing and selection API 526 Dimensions API 527 Leakage Rates ANSI B16.5 Flange Ratings 4

6 WB Series - Spring loaded safety relief valve 1 Insitu testing 2 Accessories 3 High performance springs 4 Bellows back up pisn (not shown) 5 Guiding 6 Bellows (not shown) 7 Trim 8 Seat integrity 9 Adjustable blow down 10 Nozzle design 11 API 526 face face dimensions 5

7 FEATURES AND BENEFITS Design verification all design options and the various effects of system conditions, back pressure etc. have been verified on Birkett s in-house, extensive mass flow test facility. Lighter and more compact construction continuous design improvements have created smaller and lighter valves support current industry design trends, especially space and weight savings. Interchangeable parts valves can be modified from type type, gas, liquid, conventional and bellows simply by changing only a few parts. Simplified maintenance and service - re-engineering has reduced the number of parts, making maintenance easier and more cost effective. Material selection a wide range of materials are offered including non-ferrous for low temperature and oxygen service, as well as exotic alloys specifically for the chemical and process industries. Cryogenic and oxygen service Birkett s state-of-the-art clean room and vapour degreasing facilities ensure compliance with the stringent demands of cryogenic and oxygen applications. 1 In-situ testing valves can be supplied suitable for application of in-situ set pressure verification devices. 2 Wide range of accessories available comply with international codes and suit system requirements. 3 High performance springs safety relief valve springs are specifically designed guarantee set point repeatability. 4 Bellows back-up pisn an optional auxiliary back-up pisn for balanced bellows valves ensures fail-safe operation in the event of bellows failure (see page 16). 5 Guiding surfaces the material selection of guiding components, gether with a selfaligning disc and spindle pivot point, ensures correct alignment and no galling of guiding surfaces. 6 Bellows ensures correct valve performance under difficult back pressure conditions (see page 12). 7 Trim specific gas and liquid trim designs give stable operation and eliminate the damaging effect of chatter. 8 Seat leakage integrity choice of nozzle and disc materials (coupled with superior lapping techniques) provides seat tightness API 527/ASME VIII. 9 Adjustable blow down the valve reseating pressure (blow down) can be simply adjusted suit special or specific performance requirements. 10 Nozzle design the method and location of attachment the body avoids transmission of pipe stresses the nozzle/disc mating surfaces. 11 API 526 dimensions standardised dimensions allows pipework layouts be detailed confidently. 6

8 DIFFERENT TYPES There are four basic types of WB Series safety relief valve: WB400 conventional gas type. WB300 bellows gas type. WB200 conventional liquid type. WB100 bellows liquid type. Conventional safety relief valves: Can be used on systems where the discharge is relatively simple. The pressure in the discharge system can be atmospheric, at a constant level or where the pressure may build up a maximum of 10% of the set pressure. When a constant back pressure exists, the valve should be set at the differential pressure (refer page 8). Liquid service Valves operating on liquid service require a modified valve design cope with the differing dynamics of liquid flow. A conured plug disc is used minimise initial flow rate, eliminating any potential inlet pressure drops due excessive valve lift. The valve will simmer until sufficient pressure is available generate lift. Once this has occurred, the lift will stabilise suit the flow and pressure conditions required, thus avoiding the problem of chatter. Chatter is the rapid opening and closing of the valve which can have a damaging effect on the disc and nozzle, causing it leak. Bellows safety relief valves: The WB Bellows Valves are statically balanced and can be used on more complex discharge systems such as common discharge manifolds and flares where several valves may discharge. This type of system creates a variable superimposed back pressure. The balanced bellows unit cancels out the effects of variable back pressure, on the set pressure of the safety relief valve. Gas and vapour service: The gas/vapour disc can be distinguished by the flat underside, unlike the cone profile of the liquid disc. Typical liquid relief valve disc 7

9 THE EFFECT OF BACK PRESSURE The configuration of a closed discharge pipework system, typically for xic or hazardous duty, can generate back pressure. Back pressure applied the outlet of the valve will adversely affect its performance, unless it is addressed. Back pressure may take three forms: 1. Superimposed constant back pressure This exists permanently and a conventional or bellows valve can be used. A conventional valve can be set at the differential pressure so that the spring load is adjusted take account of the back pressure. 2. Built up back pressure Built up back pressure is created by the configuration of discharge pipework systems and varies from zero when the valve is closed, a maximum, when fully open. Conventional spring loaded valves can lerate up 10% of set pressure as built up back pressure. For back pressures in excess of 10%, a balanced bellows design is required maintain valve lift. 3. Superimposed variable back pressure This is caused by other valves discharging in a common disposal system, or other circumstances that cause the back pressure be variable. Balanced bellows valves should be used for this condition, adjusted the predetermined set pressure. Constant back pressure - conventional valve Variable back pressure - balanced bellows valve 8

10 VALVE ACTION Principles of operation spring loaded safety and thermal relief valves SPRING FORCE Safety relief valves use a spring force hold a disc against a nozzle. Under normal system operating pressure, the valve will remain closed as the spring force is greater than the inlet system pressure force. The valve opens when the system pressure force becomes greater than the closing force of the spring. Spring loaded safety and thermal relief valve The WB and B/C series are designed have a short simmer, open rapidly full lift position and then re-seat at a controlled shut off pressure. This is demonstrated in the graph below, which shows the valve action and corresponding pressure at the valve inlet. SYSTEM PRESSURE FORCE POPPING PRESSURE SET PRESSURE RE-SEAT PRESSURE Popping and blowdown The opening and closing characteristics of the valve can be controlled by the adjustment of a blowdown ring, as its position affects the shape and volume of the huddling chamber. When the blowdown ring is adjusted its p position, the exit area from the huddling chamber is restricted its minimum. The valve will pop distinctly with a short simmer and long blowdown. Conversely, when the blowdown ring is in its lowest position there is a maximum exit area from the huddling chamber and the valve will have a longer simmer with a shorter blowdown. The blowdown ring can be positioned between these two extremes give the required performance, but it is usually facry set achieve re-seating 7-10% below set pressure. 9

11 LIFT CYCLE Stage 1 Closed Inlet pressure < set pressure Inlet pressure is below the set pressure. The valve is closed and there is no flow through the valve. Stage 2 Simmering Inlet pressure is = > set pressure and < popping pressure Inlet pressure increases set pressure. At this point, the spring force and system pressure force are equal; a further rise in inlet pressure will then begin lift the disc slightly. A small amount of fluid is released in the huddling chamber (the valve simmers). The system fluid is now acting on a larger area inside the huddling chamber. Stage 3 Popping and opening Inlet pressure = > popping pressure, valve fully open The inlet pressure acting on a larger area produces a significant force accelerate the opening. A combination of this pressure force, the kinetic energy from the fluid within the nozzle and the deflection force of the fluid flow turning through the reaction hood, is transformed in disc lifting force. The valve pops open at < 5% overpressure and the valve reaches the full open position at 110% of set pressure, in accordance with international codes. Stage 4 Reseating Inlet pressure falls re-seating pressure As system pressure starts fall, the force from the spring begins close the valve. Typically, the system pressure falls between 5-10% below the valve set pressure at which point the spring force accelerates the valve disc re-seat the valve. The difference between the set pressure and the re-seating pressure is known as blowdown. 10

12 WB CONVENTIONAL GAS TYPE (up and including class 600) ITEM PART CARBON STEEL STAINLESS STEEL 1 Body SA 216-WCB CARB ST SA 351-CF8M ST ST 2 Casing SA 216-WCB CARB ST SA 351-CF8M ST ST 3 Cap SA 216-WCB CARB ST SA 351-CF8M ST ST 4* Nozzle 316 ST ST 316 ST ST 5* Disc 316 ST ST 316 ST ST 6* Disc holder ASTM A L ASTM A L 8 Blowdown ring SA 351-CF8M ST ST SA 351-CF8M ST ST 9 Guide Assy CARBON ST/17-4 ST ST 316L/17-4 ST ST 10* Spindle ASTM A ASTM A Lower spring plate ASTM A /Ni PLT ASTM A Adjusting screw ASTM A ASTM A Locking nut ASTM A ASTM A L 14 Setting screw ASTM A ASTM A Setting screw rod ASTM A L ASTM A L 18 Stud SA 193-B7 CR/MOL ST SA 193-B8T ST ST 19 Nut SA 194-2H CARB ST SA 194-8T ST ST 22* Spring CARBON STEEL ASTM A * Body gasket ST-706 ST * Cap gasket ST-706 ST * Set screw gasket ST-706 ST * Ball AISI 440C ST ST AISI 440C ST ST 32 Upper spring plate ASTM A /Ni PLT ASTM A Data plate 321 ST ST 321 ST ST 34 Hammer drive screw ELECTRO BRASSED ST ASTM A L 35 Grooved pin ASTM A ASTM A Drain plug HTS HOLO-KROME ASTM A L 80* Circlip ASTM A ASTM A * Recommended spares 11

13 WB BALANCED BELLOWS GAS TYPE (up and including class 600) ITEM PART CARBON STEEL STAINLESS STEEL 1 Body SA 216-WCB CARB ST SA 351-CF8M ST ST 2 Casing SA 216-WCB CARB ST SA 351-CF8M ST ST 3 Cap SA 216-WCB CARB ST SA 351-CF8M ST ST 4* Nozzle 316 ST ST 316 ST ST 5* Disc 316 ST ST 316 ST ST 6* Disc holder INCLUDED IN ITEM 23 INCLUDED IN ITEM 23 8 Blowdown ring SA 351-CF8M ST ST SA 351-CF8M ST ST 9 Guide Assy CARBON ST/17-4 ST ST 316 L/17-4 ST ST 10* Spindle ASTM A ASTM A Lower spring plate ASTM A /Ni PLT ASTM A Adjusting screw ASTM A ASTM A Locking nut ASTM A ASTM A L 14 Setting screw ASTM A ASTM A Set screw rod ASTM A L ASTM A L 18 Stud SA 193-B7 CR/MOL ST SA 193-B8T ST ST 19 Nut SA 194-2H CARB ST SA 194-8T ST ST 22* Spring CARBON STEEL ASTM A * Bellows assembly ASTM A L/SA L ASTM A L/SA L 27* Body gasket ST-706 ST * Cap gasket ST-706 ST * Set screw gasket ST-706 ST * Ball AISI 440C ST ST AISI 440C ST ST 32 Upper spring plate ASTM A /Ni PLT ASTM A Data plate 321 ST ST 321 ST ST 34 Hammer drive screw ELECTRO BRASSED ST ASTM A L 35 Grooved pin ASTM A ASTM A Drain plug HTS HOLO-KROME ASTM A L 80* Circlip ASTM A ASTM A * Recommended spares 12

14 WB CONVENTIONAL GAS TYPES (class 900 and above) ITEM PART CARBON STEEL STAINLESS STEEL 1 Body SA 216-WCB CARB ST SA 351-CF8M ST ST 2 Casing SA 216-WCB CARB ST SA 351-CF8M ST ST 3 Cap SA 216-WCB CARB ST SA 351-CF8M ST ST 4* Nozzle 316 ST ST 316 ST ST 5* Disc 316 ST ST 316 ST ST 6* Disc holder ASTM A L ASTM A L 7 Reaction hood ASTM A ASTM A Blowdown ring SA 351-CF8M ST ST SA 351-CF8M ST ST 9 Guide plate 17-4 ST ST 17-4 ST ST 10* Spindle ASTM A ASTM A Lower spring cap ASTM A /Ni PLT ASTM A Adjusting screw ASTM A ASTM A Locking nut ASTM A ASTM A L 14 Setting screw ASTM A ASTM A Setting screw rod ASTM A L ASTM A L 16* Tabwasher BS S15 ST ST BS S15 ST ST 17* Pinning screw ASTM A ASTM A Body stud SA 193-B7 CR/MOL ST SA 193-B8T ST ST 19 Body nut SA 194-2H CARB ST SA 194-8T ST ST 20 Casing stud SA 193-B7 CR/MOL ST SA 193-B8T ST ST 21 Casing nut SA 194-2H CARB ST SA 194-8T ST ST 22* Spring CARBON STEEL ASTM A * Spindle head ASTM A ASTM A * Body gasket ST-706 ST * Cap gasket ST-706 ST * Setting screw gasket ST-706 ST * Ball AISI 440C ST ST AISI 440C ST ST 32 Upper spring cap ASTM A /Ni PLT ASTM A Data plate 321 ST ST 321 ST ST 34 Hammer drive screw ELECTRO BRASSED ST ASTM A L 35* Grooved pin ASTM A ASTM A Drain plug HTS HOLO-KROME ASTM A L * Recommended spares 13

15 WB BALANCED BELLOWS GAS TYPE (class 900 and above) ITEM PART CARBON STEEL STAINLESS STEEL 1 Body SA 216-WCB CARB ST SA 351-CF8M ST ST 2 Casing SA 216-WCB CARB ST SA 351-CF8M ST ST 3 Cap SA 216-WCB CARB ST SA 351-CF8M ST ST 4* Nozzle 316 ST ST 316 ST ST 5* Disc 316 ST ST 316 ST ST 6* Disc holder base ASTM A ASTM A Reaction hood ASTM A ASTM A Blowdown ring SA 351-CF8M ST ST SA 351-CF8M ST ST 9 Guide plate 17-4 ST ST 17-4 ST ST 10* Spindle ASTM A ASTM A Lower spring cap ASTM A /Ni PLT ASTM A Adjusting screw ASTM A ASTM A Locking nut ASTM A ASTM A L 14 Setting screw ASTM A ASTM A Setting screw rod ASTM A L ASTM A L 16* Tabwasher BS S15 ST ST BS S15 ST ST 17* Pinning screw ASTM A ASTM A Body stud SA 193-B7 CR/MOL ST SA 193-B8T ST ST 19 Body nut SA 194-2H CARB ST SA 194-8T ST ST 20 Casing stud SA 193-B7 CR/MOL ST SA 193-B8T ST ST 21 Casing nut SA 194-2H CARB ST SA 194-8T ST ST 22* Spring CARBON STEEL ASTM A * Bellows SA L SA L 24* Spindle head ASTM A ASTM A Pisn ASTM A ASTM A Guide spindle ASTM A ASTM A * Body gasket ST-706 ST Cap gasket ST-706 ST Setting screw gasket ST-706 ST Ball AISI 440C ST ST AISI 440C ST ST 32 Upper spring cap ASTM A /Ni PLT ASTM A Data plate 321 ST ST 321 ST ST 34 Hammer drive screw ELECTRO BRASSED ST ASTM A L 35 Grooved pin ASTM A ASTM A Drain plug HTS HOLO-KROME ASTM A L 50 Grubscrew ASTM A ASTM A * Recommended spares 14

16 ACCESSORIES Screwed cap This is the standard option on all valves. Bolted cap Option available on the WB Series when required by the cusmer or for critical service where fragile gaskets materials may be fitted. Open lever* The open lever assembly is not pressure tight and is therefore only suitable where vapour can safely be allowed escape atmosphere. Packed lever* The design of the packed lever assembly ensures that leakage does not occur when the valve is open or when back pressure is present. *A lift lever can be used test for correct valve operation where corrosion or deposits could prevent the valve from opening. They can be used release foreign particles trapped on the seat and must be fitted when codes dictate. GAG SCREW SEALING PLUG Test gag The test gag is used prevent the safety valve from lifting. This is mainly used when carrying out a hydrostatic test on the system, during commissioning. After testing, the test gag must be removed and replaced with the sealing plug. 15

17 FERRULE Ferrule (government ring) A ferrule, sometimes known as a government ring, is a collar fitted beneath the head of the pressure adjusting screw. Some authorities will require a ferrule be fitted prevent unauthorised interference with the set pressure. Soft seat An O-ring seal offers maximum seat tightness, over and above that of the standard metal-metal seats. A wide range of seal materials are available including Vin, Nitrile, Kalrez and PTFE. For high integrity seat leakage, specify soft seat. Steam jacket Some process media can solidify or form crystals if they cool within the system. The medium within the valve nozzle is not in the flow path and thus cooling can occur. Should the medium solidify, crystallise, or if sublimation of vapour was occur within the nozzle, the valve may not lift. The steam jacket is designed keep the process medium hot, helping maximise plant safety. The steam jacket has both an inlet and outlet so that low pressure steam can be passed through the jacket, keeping the valves hot. This allows the valves stay operational, enabling the valve successfully relieve pressure, should an overpressure situation occur. The steam jacket is manufactured out of material that is compatible with the body of the valve and the connections the jacket can either be flanged or screwed. Auxiliary back-up pisn In the event of bellows failure, a potentially dangerous situation can arise. The back pressure causes an out-of-balance situation which may cause: 1 Increase in set pressure. 2 Decrease in flow capacity. 3 Increase in re-seat pressure. Specifying bellows valves with an auxiliary back-up pisn ensures that the above does not occur. The pisn itself has the same effective diameter as the failed bellows, so any effect of the back pressure increasing the set pressure is counteracted by an upward thrust of the pisn. This is an added safety feature. The WB 300 valve has incorporated the auxiliary back-up pisn since its inception. It is available as standard in all pressure classes 900 and above and as an optional feature for class 600 and below. To ensure absolute safety, specify the auxiliary back-up pisn. 16

18 WB SERIES FIGURE NUMBERING SYSTEM / Inlet diameter 1-8 API orifice letter D - T Outlet diameter 2-10 Design H ANSI 150, 300 and 600 / ANSI 900, 1500 and 2500 Accessories B Auxiliary back-up pisn C Bolted cap D Screwed cap F Ferrule (Government ring) G Test gag H* High Pressure M Open lever P Packed lever R Soft seat S Special feature 3 WB300 Bellows Valve type 1 Liquid bellows 2 Liquid conventional 3 Vapour bellows 4 Vapour conventional ANSI flange rating inlet x outlet x x x x x x x x 300 O Special Flange face 1 ANSI RF x RF 2 ANSI RTJ inlet x RF O Special Trim material nozzle and disc 1 Stainless steel PH 17/4 2 Stainless steel Aluminium bronze / Monel 4 Hastelloy B 5 Stainless steel 316 stellited 6 Monel 7 Stainless steel 304 O Special Spring material 1 Carbon steel 2 Stainless steel Tungsten alloy 9 Hastelloy B A Aluminium Coated CS N Stainless steel PH 17/4 Q Stainless steel PH 17/4 NACE T Aluminium Coated Tungsten Z Inconel X750 O Special *In some instances when both high pressures and alloy springs are required, the H needs adding accessories. See individual orifice pages. Body material 1 Carbon steel WCB 2 Carbon steel WCB NACE 3 Stainless steel CF8M NACE 4 Stainless steel CF8M 5 Carbon steel low temperature LCB 6 Bronze 8 Carbon steel WC6-0.5% Moly 9 Hastelloy B O Special 17

19 RECOMMENDED MATERIAL TEMPERATURE RANGES Description Minimum Maximum deg F deg C deg F deg C BODY 1 Carbon steel SA 216-WCB Carbon steel (NACE) SA 216-WCB Stainless steel (NACE) SA 351-CF8M Stainless steel SA 351-CF8M Low Temp. CS SA 352-LCB Bronze (Oxygen spec.) BS 1400 LG % MOLY CS SA 217-WC Hastelloy B SA 494-N12MV SPRING 1 Carbon steel A Aluminium coated CS Stainless steel (316) Tungsten alloy (BH12) T Aluminium coated tungsten Hastelloy B N Stainless steel (PH17/4) Q Stainless steel (PH17/4 NACE) Z Inconel X TRIM (Nozzle and disc) 1 Stainless steel (PH 17/4 NACE HRC) Stainless steel (316) Al. Bronze/Monel Hastelloy B Stainless steel (316 Stellited HRC) Monel Stainless steel GASKETS NAF (ST-706) Graphite (Supergraf) Gylon SOFT SEAT Nitrile Vin Silicon Ethylene Propylene PTFE Kalrez BOLTING B7 Alloy steel B8T Stainless Steel Monel K Notes 1 All temperatures are at valve inlet. 2 Trim items 1 and 5 are recommended for maximum durability. 3 Alternative materials may be specified if agreed on enquiry. 18

20 VALVE SELECTION GUIDE D in 2 71 mm 2 TEMPERATURE LIMITS API SPRING BODY STAINLESS STEEL CARBON STEEL TUNGSTEN SS - CF8M CARBON STEEL - WCB CS - WC6 SET PRESSURE - PSIG SET PRESSURE - BAR G ORIFICE D (All dimensions in inches) Size Rating A B C* D E F G H Wt (ins) lbs (kg) 1 x x /8 3/4 40 (18) 300 x /8 3/4 40 (18) 600 x /8 3/4 42 (19) 1 1 /2 x x /8 3/4 90 (41) 1500 x /8 3/4 97 (44) 1 1 /2 x x /8 3/4 115 (52) * If a gag is fitted, add 0.5 ins. If a bellows is fitted in the 1 x 2 inch valve add inch. If a lever is fitted, add a maximum of 3.5 inch. (Only if flange rating is 600# or less.) For certified height (c), consult facry. Vent hole H on bellows valves only. 19

21 VALVE SELECTION TABLE D in 2 71 mm 2 Flanges ANSI Key Valve size No. inlet x outlet Inlet Outlet Body (ins) Mat l -76 F -450 F -60 C -268 C Max. Set Pressure (psig) and Temperature Limits -21 F -75 F -30 C -59 C 100 F -20 F 38 C -29 C 450 F 800 F 1000 F 232 C 427 C 538 C Max. Back Pressure (psig) Conventional Valve Balanced Bellows Valve 1 1 x 2 150#RF 150#RF x 2 300#RF 150#RF x 2 600#RF 150#RF WCB /2 x 2 900#RF 300#RF /2 x #RF 300#RF /2 x #RF 300#RF x 2 300#RF 150#RF x 2 600#RF 150#RF /2 x 2 900#RF 300#RF WC /2 x #RF 300#RF /2 x #RF 300#RF x 2 150#RF 150#RF x 2 300#RF 150#RF x 2 600#RF 150#RF CF8M /2 x 2 900#RF 300#RF /2 x #RF 300#RF /2 x #RF 300#RF RF=Raised Face Minimum set pressure limits for metal seat trim Conventional 7 psig Bellows - Gas 22 psig Bellows - Liquid 59 psig* Conventional 2 psig (Inverted) *For liquid bellows valves below this pressure refer facry Note: Soft seated valves require a minimum set pressure of 15 psig. High Pressure Version There is no requirement have an high pressure version for this orifice. 20

22 VALVE SELECTION GUIDE E in mm 2 TEMPERATURE LIMITS API SPRING BODY STAINLESS STEEL CARBON STEEL TUNGSTEN SS - CF8M CARBON STEEL - WCB CS - WC6 SET PRESSURE - PSIG SET PRESSURE - BAR G ORIFICE E (All dimensions in inches) Size Rating A B C* D E F G H Wt (ins) lbs (kg) 1 x x /8 3/4 40 (18) 300 x /8 3/4 40 (18) 600 x /8 3/4 42 (19) 1 1 /2 x x /8 3/4 90 (41) 1500 x /8 3/4 97 (44) 1 1 /2 x x /8 3/4 115 (52) * If a gag is fitted, add 0.5 ins. If a bellows is fitted in the 1 x 2 inch valve add inch. If a lever is fitted, add a maximum of 3.5 inch. (Only if flange rating is 600# or less.) For certified height (c), consult facry. Vent hole H on bellows valves only. 21

23 VALVE SELECTION TABLE E in mm 2 Flanges ANSI Key Valve size No. inlet x outlet Inlet Outlet Body (ins) Mat l -76 F -450 F -60 C -268 C Max. Set Pressure (psig) and Temperature Limits -21 F -75 F -30 C -59 C 100 F -20 F 38 C -29 C 450 F 800 F 1000 F 232 C 427 C 538 C Max. Back Pressure (psig) Conventional Valve Balanced Bellows Valve 1 1 x 2 150#RF 150#RF x 2 300#RF 150#RF x 2 600#RF 150#RF WCB /2 x 2 900#RF 300#RF /2 x #RF 300#RF /2 x #RF 300#RF x 2 300#RF 150#RF x 2 600#RF 150#RF /2 x 2 900#RF 300#RF WC /2 x #RF 300#RF /2 x #RF 300#RF x 2 150#RF 150#RF x 2 300#RF 150#RF x 2 600#RF 150#RF CF8M /2 x 2 900#RF 300#RF /2 x #RF 300#RF /2 x #RF 300#RF RF=Raised Face Minimum set pressure limits for metal seat trim Conventional 7 psig Bellows - Gas 22 psig Bellows - Liquid 59 psig* Conventional 2 psig (Inverted) *For liquid bellows valves below this pressure refer facry Note: Soft seated valves require a minimum set pressure of 15 psig. High Pressure Version There is no requirement have an high pressure version for this orifice. 22

24 VALVE SELECTION GUIDE F in mm 2 TEMPERATURE LIMITS API SPRING BODY CS - WC6 STAINLESS STEEL CARBON STEEL TUNGSTEN SS - CF8M CARBON STEEL - WCB SET PRESSURE - PSIG SET PRESSURE - BAR G ORIFICE F (All dimensions in inches) Size Rating A B C* D E F G H Wt (ins) lbs (kg) 1 1 /2 x x /8 3/4 46 (21) 300 x /8 3/4 46 (21) 600 x /8 3/4 46 (21) 1 1 /2 x x /8 3/4 101 (46) 1500 x /8 3/4 101 (46) 2500 x /8 3/4 117 (53) * If a gag is fitted, add 0.5 ins. If a lever is fitted, add a maximum of 3.5 inch. (Only if flange rating is 600# or less.) For certified height (c), consult facry. Vent hole H on bellows valves only. 23

25 VALVE SELECTION TABLE F in mm 2 Flanges ANSI Key Valve size No. inlet x outlet Inlet Outlet Body (ins) Mat l -76 F -450 F -60 C -268 C Max. Set Pressure (psig) and Temperature Limits -21 F -75 F -30 C -59 C 100 F -20 F 38 C -29 C 450 F 800 F 1000 F 232 C 427 C 538 C Max. Back Pressure (psig) Conventional Valve Balanced Bellows Valve /2 x 2 150#RF 150#RF /2 x 2 300#RF 150#RF /2 x 2 600#RF 150#RF WCB /2 x 3 900#RF 300#RF /2 x #RF 300#RF /2 x #RF 300#RF /2 x 2 300#RF 150#RF /2 x 2 600#RF 150#RF /2 x 3 900#RF 300#RF WC /2 x #RF 300#RF /2 x #RF 300#RF /2 x 2 150#RF 150#RF /2 x 2 300#RF 150#RF /2 x 2 600#RF 150#RF /2 x 3 900#RF 300#RF CF8M /2 x #RF 300#RF /2 x #RF 300#RF RF=Raised Face Minimum set pressure limits for metal seat trim Conventional 7 psig Bellows - Gas 22 psig Bellows - Liquid 59 psig* Conventional 2 psig (Inverted) *For liquid bellows valves below this pressure refer facry Note: Soft seated valves require a minimum set pressure of 15 psig. High Pressure Version There is no requirement have an high pressure version for this orifice. 24

26 VALVE SELECTION GUIDE G in mm 2 TEMPERATURE LIMITS API SPRING BODY CS - WC6 STAINLESS STEEL CARBON STEEL TUNGSTEN SS - CF8M CARBON STEEL - WCB SET PRESSURE - PSIG SET PRESSURE - BAR G ORIFICE G (All dimensions in inches) Size Rating A B C* D E F G H Wt (ins) lbs (kg) 1 1 /2 x x /8 3/4 60 (27) 300 x /8 3/4 64 (29) 600 x /8 3/4 66 (30) 900 x /8 3/4 119 (54) 2 x x /2 3/4 126 (57) 2500 x /2 3/4 139 (63) * If a gag is fitted, add 0.5 ins. If a lever is fitted, add a maximum of 3.5 inch. (Only if flange rating is 600# or less.) For certified height (c), consult facry. Vent hole H on bellows valves only. 25

27 VALVE SELECTION TABLE G in mm 2 Flanges ANSI Key Valve size No. inlet x outlet Inlet Outlet Body (ins) Mat l -76 F -450 F -60 C -268 C Max. Set Pressure (psig) and Temperature Limits -21 F -75 F -30 C -59 C 100 F -20 F 38 C -29 C 450 F 800 F 1000 F 232 C 427 C 538 C Max. Back Pressure (psig) Conventional Valve Balanced Bellows Valve /2 x 3 150#RF 150#RF /2 x 3 300#RF 150#RF /2 x 3 600#RF 150#RF WCB /2 x 3 900#RF 300#RF x #RF 300#RF x #RF 300#RF /2 x 3 300#RF 150#RF /2 x 3 600#RF 150#RF /2 x 3 900#RF 300#RF WC x #RF 300#RF x #RF 300#RF /2 x 3 150#RF 150#RF /2 x 3 300#RF 150#RF /2 x 3 600#RF 150#RF /2 x 3 900#RF 300#RF CF8M x #RF 300#RF x #RF 300#RF RF=Raised Face Minimum set pressure limits for metal seat trim Conventional 13 psig Bellows - Gas 13 psig Bellows - Liquid 40 psig* Conventional 2 psig (Inverted) *For liquid bellows valves below this pressure refer facry Note: Soft seated valves require a minimum set pressure of 15 psig. High Pressure Version There is no requirement have an high pressure version for this orifice. 26

28 VALVE SELECTION GUIDE H in mm 2 TEMPERATURE LIMITS API 526 SPRING BODY STAINLESS STEEL CARBON STEEL TUNGSTEN SS - CF8M CARBON STEEL - WCB CS - WC6 SET PRESSURE - PSIG SET PRESSURE - BAR G ORIFICE H (All dimensions in inches) Size Rating A B C* D E F G H Wt (ins) lbs (kg) 1 1 /2 x x /8 3/4 60 (27) 300 x /8 3/4 60 (27) 2 x x /8 3/4 64 (29) 600 x /8 3/4 86 (39) 900 x /2 3/4 176 (80) 1500 x /2 3/4 187 (85) * If a gag is fitted, add 0.5 ins. If a lever is fitted, add a maximum of 3.5 inch. (Only if flange rating is 600# or less.) For certified height (c), consult facry. Vent hole H on bellows valves only. 27

29 VALVE SELECTION TABLE H in mm 2 Flanges ANSI Key Valve size No. inlet x outlet Inlet Outlet Body (ins) Mat l -76 F -450 F -60 C -268 C Max. Set Pressure (psig) and Temperature Limits -21 F -75 F -30 C -59 C 100 F -20 F 38 C -29 C 450 F 800 F 1000 F 232 C 427 C 538 C Max. Back Pressure (psig) Conventional Valve Balanced Bellows Valve /2 x 3 150#RF 150#RF /2 x 3 300#RF 150#RF x 3 300#RF 150#RF WCB x 3 600#RF 150#RF x 3 900#RF 150#RF x #RF 300#RF x 3 300#RF 150#RF x 3 600#RF 150#RF x 3 900#RF 150#RF WC x #RF 300#RF /2 x 3 150#RF 150#RF /2 x 3 300#RF 150#RF x 3 300#RF 150#RF x 3 600#RF 150#RF CF8M x 3 900#RF 150#RF x #RF 300#RF RF=Raised Face Minimum set pressure limits for metal seat trim Conventional 7 psig Bellows - Gas 13 psig Bellows - Liquid 28 psig* Conventional 2 psig (Inverted) *For liquid bellows valves below this pressure refer facry Note: Soft seated valves require a minimum set pressure of 15 psig. High Pressure Version. Certain spring materials cannot be used in the low pressure version of the valve, up the maximum pressure. If the required set pressure with your choice of spring material is in excess of the figure shown in the table either choose another material or add H the valve accessories select an high pressure valve. Inlet Max. Set Spring Material (pressures in Psig) Orifice rating Pressure Psig Carbon st. 316 SS Tungsten 17/4PH 17/4PH NACE Inconel X H 150# 285 n/a n/a n/a n/a n/a n/a 1.5H 300# 285 n/a n/a n/a n/a n/a n/a 2H 300# 740 n/a n/a n/a n/a n/a n/a 2H 600# 1480 n/a 1000 n/a n/a 1000 n/a 28

30 VALVE SELECTION GUIDE in 2 J 830 mm 2 TEMPERATURE LIMITS API SPRING BODY STAINLESS STEEL CARBON STEEL TUNGSTEN SS - CF8M CARBON STEEL - WCB SET PRESSURE - PSIG CS - WC SET PRESSURE - BAR G ORIFICE J (All dimensions in inches) Size Rating A B C* D E F G H Wt (ins) lbs (kg) 2 x x /8 3/4 64 (29) 300 x /8 3/4 64 (29) 3 x x /8 3/4 82 (37) 600 x /8 3/4 99 (45) 900 x /2 3/4 231 (105) 1500 x /2 3/4 253 (115) * If a gag is fitted, add 0.5 ins. If a lever is fitted, add a maximum of 3.5 inch. (Only if flange rating is 600# or less.) For certified height (c), consult facry. Vent hole H on bellows valves only. 29

31 VALVE SELECTION TABLE in 2 J 830 mm 2 Flanges ANSI Key Valve size No. inlet x outlet Inlet Outlet Body (ins) Mat l -76 F -450 F -60 C -268 C Max. Set Pressure (psig) and Temperature Limits -21 F -75 F -30 C -59 C 100 F -20 F 38 C -29 C 450 F 800 F 1000 F 232 C 427 C 538 C Max. Back Pressure (psig) Conventional Valve Balanced Bellows Valve 1 2 x 3 150#RF 150#RF x 3 300#RF 150#RF x 4 300#RF 150#RF WCB x 4 600#RF 150#RF x 4 900#RF 150#RF x #RF 300#RF x 4 300#RF 150#RF x 4 600#RF 150#RF WC x 4 900#RF 150#RF x #RF 300#RF x 3 150#RF 150#RF x 3 300#RF 150#RF x 4 300#RF 150#RF CF8M 14 3 x 4 600#RF 150#RF x 4 900#RF 150#RF x #RF 300#RF RF=Raised Face Minimum set pressure limits for metal seat trim Conventional 5 psig Bellows - Gas 13 psig Bellows - Liquid 34 psig* Conventional 1.5 psig (Inverted) *For liquid bellows valves below this pressure refer facry Note: Soft seated valves require a minimum set pressure of 15 psig. High Pressure Version. Certain spring materials cannot be used in the low pressure version of the valve, up the maximum pressure. If the required set pressure with your choice of spring material is in excess of the figure shown in the table either choose another material or add H the valve accessories select an high pressure valve. Inlet Max. Set Spring Material (pressures in Psig) Orifice rating Pressure Psig Carbon st. 316 SS Tungsten 17/4PH 17/4PH NACE Inconel X750 2J 150# 285 n/a n/a n/a n/a n/a n/a 2J 300# 285 n/a n/a n/a n/a n/a n/a 3J 300# 740 n/a 500 n/a n/a 430 n/a 3J 600# 1480 n/a 900 n/a

32 VALVE SELECTION GUIDE K in mm 2 TEMPERATURE LIMITS API SPRING BODY INCONEL CS - WC6 STAINLESS STEEL CARBON STEEL TUNGSTEN SS - CF8M CARBON STEEL - WCB SET PRESSURE - PSIG SET PRESSURE - BAR G ORIFICE K (All dimensions in inches) Size Rating A B C* D E F G H Wt (ins) lbs (kg) 3 x x /8 3/4 108 (49) 300 x /8 3/4 108 (49) 600 x /8 3/4 141 (64) 3 x x /4 3/4 339 (154) 1500 x /4 3/4 353 (160) * If a gag is fitted, add 0.5 ins. If a lever is fitted, add a maximum of 3.5 inch. (Only if flange rating is 600# or less.) For certified height (c), consult facry. Vent hole H on bellows valves only. 31

33 VALVE SELECTION TABLE K in mm 2 Flanges ANSI Key Valve size No. inlet x outlet Inlet Outlet Body (ins) Mat l -76 F -450 F -60 C -268 C Max. Set Pressure (psig) and Temperature Limits -21 F -75 F -30 C -59 C 100 F -20 F 38 C -29 C 450 F 800 F 1000 F 232 C 427 C 538 C Max. Back Pressure (psig) Conventional Valve Balanced Bellows Valve 1 3 x 4 150#RF 150#RF x 4 300#RF 150#RF x 4 600#RF 150#RF WCB x 6 900#RF 150#RF x #RF 300#RF x 4 300#RF 150#RF x 4 600#RF 150#RF WC6 8 3 x 6 900#RF 150#RF x #RF 300#RF x 4 150#RF 150#RF x 4 300#RF 150#RF x 4 600#RF 150#RF CF8M x 6 900#RF 150#RF x #RF 300#RF RF=Raised Face Minimum set pressure limits for metal seat trim Conventional 5 psig Bellows - Gas 13 psig Bellows - Liquid 26 psig* Conventional 1.5 psig (Inverted) *For liquid bellows valves below this pressure refer facry Note: Soft seated valves require a minimum set pressure of 15 psig. High Pressure Version. Certain spring materials can not be used in the low pressure version of the valve, up the maximum pressure. If the required set pressure with your choice of spring material is in excess of the figure shown in the table either choose another material or add H the valve accessories select an high pressure valve. Inlet Max. Set Spring Material (pressures in Psig) Orifice rating Pressure Psig Carbon st. 316 SS Tungsten 17/4PH 17/4PH NACE Inconel X750 K 150# 285 n/a n/a n/a n/a n/a n/a K 300# 740 n/a 450 n/a n/a 600 n/a K 600# 1480 n/a 750 n/a n/a

34 VALVE SELECTION GUIDE L in mm 2 TEMPERATURE LIMITS API SPRING BODY CS - WC6 STAINLESS STEEL CARBON STEEL TUNGSTEN SS - CF8M CARBON STEEL - WCB SET PRESSURE - PSIG SET PRESSURE - BAR G ORIFICE L (All dimensions in inches) Size Rating A B C* D E F G H Wt (ins) lbs (kg) 3 x x /8 3/4 108 (49) 300 x /8 3/4 108 (49) 4 x x / (106) 600 x / (113) 900 x / (160) 1500 x / (164) * If a gag is fitted, add 0.5 ins. If a lever is fitted, add a maximum of 3.5 inch. (Only if flange rating is 600# or less.) For certified height (c), consult facry. Vent hole H on bellows valves only. 33

35 VALVE SELECTION TABLE L in mm 2 Flanges ANSI Key Valve size No. inlet x outlet Inlet Outlet Body (ins) Mat l -76 F -450 F -60 C -268 C Max. Set Pressure (psig) and Temperature Limits -21 F -75 F -30 C -59 C 100 F -20 F 38 C -29 C 450 F 800 F 1000 F 232 C 427 C 538 C Max. Back Pressure (psig) Conventional Valve Balanced Bellows Valve 1 3 x 4 150#RF 150#RF x 4 300#RF 150#RF x 6 300#RF 150#RF WCB x 6 600#RF 150#RF x 6 900#RF 150#RF x #RF 150#RF x 6 300#RF 150#RF x 6 600#RF 150#RF WC x 6 900#RF 150#RF x #RF 150#RF x 4 150#RF 150#RF x 4 300#RF 150#RF x 6 300#RF 150#RF CF8M x 6 600#RF 150#RF x 6 900#RF 150#RF RF=Raised Face Minimum set pressure limits for metal seat trim Conventional 5 psig Bellows - Gas 13 psig Bellows - Liquid 23 psig* Conventional 1.5 psig (Inverted) *For liquid bellows valves below this pressure refer facry Note: Soft seated valves require a minimum set pressure of 15 psig. High Pressure Version. Certain spring materials cannot be used in the low pressure version of the valve, up the maximum pressure. If the required set pressure with your choice of spring material is in excess of the figure shown in the table either choose another material or add H the valve accessories select an high pressure valve. Inlet Max. Set Spring Material (pressures in Psig) Orifice rating Pressure Psig Carbon st. 316 SS Tungsten 17/4PH 17/4PH NACE Inconel X750 3L 150# 285 n/a n/a n/a n/a 255 n/a 3L 300# 285 n/a n/a n/a n/a 255 n/a 4L 300# 740 n/a n/a n/a n/a n/a n/a 4L 600# 1000 n/a 850 n/a n/a 825 n/a 34

36 VALVE SELECTION GUIDE M 3.60 in mm 2 TEMPERATURE LIMITS API SPRING BODY INCONEL CS - WC6 STAINLESS STEEL CARBON STEEL TUNGSTEN SS - CF8M CARBON STEEL - WCB SET PRESSURE - PSIG SET PRESSURE - BAR G ORIFICE M (All dimensions in inches) Size Rating A B C* D E F G H Wt (ins) lbs (kg) 4 x x / (106) 300 x / (106) 600 x / (113) 900 x / (171) * If a gag is fitted, add 0.5 ins. If a lever is fitted, add a maximum of 3.5 inch. (Only if flange rating is 600# or less.) For certified height (c), consult facry. Vent hole H on bellows valves only. 35

37 VALVE SELECTION TABLE M 3.60 in mm 2 Flanges ANSI Key Valve size No. inlet x outlet Inlet Outlet Body (ins) Mat l -76 F -450 F -60 C -268 C Max. Set Pressure (psig) and Temperature Limits -21 F -75 F -30 C -59 C 100 F -20 F 38 C -29 C 450 F 800 F 1000 F 232 C 427 C 538 C Max. Back Pressure (psig) Conventional Valve Balanced Bellows Valve 1 4 x 6 150#RF 150#RF x 6 300#RF 150#RF WCB 3 4 x 6 600#RF 150#RF x 6 900#RF 150#RF x 6 300#RF 150#RF x 6 600#RF 150#RF WC x 6 900#RF 150#RF x 6 150#RF 150#RF x 6 300#RF 150#RF CF8M x 6 600#RF 150#RF RF=Raised Face Minimum set pressure limits for metal seat trim Conventional 4 psig Bellows - Gas 13 psig Bellows - Liquid 27 psig* Conventional 1.5 psig (Inverted) *For liquid bellows valves below this pressure refer facry Note: Soft seated valves require a minimum set pressure of 15 psig. High Pressure Version. Certain spring materials can not be used in the low pressure version of the valve, up the maximum pressure. If the required set pressure with your choice of spring material is in excess of the figure shown in the table either choose another material or add H the valve accessories select an high pressure valve. Inlet Max. Set Spring Material (pressures in Psig) Orifice rating Pressure Psig Carbon st. 316 SS Tungsten 17/4PH 17/4PH NACE Inconel X750 M 150# 285 n/a n/a n/a n/a n/a n/a M 300# 740 n/a 500 n/a n/a 590 n/a M 600# 1100 n/a 825 n/a

38 VALVE SELECTION GUIDE N 4.34 ins mm 2 TEMPERATURE LIMITS API SPRING BODY STAINLESS STEEL CARBON STEEL TUNGSTEN SS - CF8M CARBON STEEL - WCB SET PRESSURE - PSIG CS - WC SET PRESSURE - BAR G ORIFICE N (All dimensions in inches) Size Rating A B C* D E F G H Wt (ins) lbs (kg) 4 x x / (110) 300 x / (110) 600 x / (117) 900 x / (179) * If a gag is fitted, add 0.5 ins. If a lever is fitted, add a maximum of 3.5 inch. (Only if flange rating is 600# or less.) For certified height (c), consult facry. Vent hole H on bellows valves only. 37

39 VALVE SELECTION TABLE N 4.34 ins mm 2 Flanges ANSI Key Valve size No. inlet x outlet Inlet Outlet Body (ins) Mat l -76 F -450 F -60 C -268 C Max. Set Pressure (psig) and Temperature Limits -21 F -75 F -30 C -59 C 100 F -20 F 38 C -29 C 450 F 800 F 1000 F 232 C 427 C 538 C Max. Back Pressure (psig) Conventional Valve Balanced Bellows Valve 1 4 x 6 150#RF 150#RF x 6 300#RF 150#RF WCB 3 4 x 6 600#RF 150#RF x 6 900#RF 150#RF x 6 300#RF 150#RF x 6 600#RF 150#RF WC x 6 900#RF 150#RF x 6 150#RF 150#RF x 6 300#RF 150#RF CF8M x 6 600#RF 150#RF RF=Raised Face Minimum set pressure limits for metal seat trim Conventional 5 psig Bellows - Gas 13 psig Bellows - Liquid 29 psig* Conventional 1.5 psig (Inverted) *For liquid bellows valves below this pressure refer facry Note: Soft seated valves require a minimum set pressure of 15 psig. High Pressure Version. Certain spring materials can not be used in the low pressure version of the valve, up the maximum pressure. If the required set pressure with your choice of spring material is in excess of the figure shown in the table either choose another material or add H the valve accessories select an high pressure valve. Inlet Max. Set Spring Material (pressures in Psig) Orifice rating Pressure Psig Carbon st. 316 SS Tungsten 17/4PH 17/4PH NACE Inconel X750 N 150# 285 n/a n/a n/a n/a n/a n/a N 300# 740 n/a 680 n/a n/a 700 n/a N 600# 1000 n/a n/a n/a n/a n/a n/a 38

40 VALVE SELECTION GUIDE P 6.38 ins mm 2 TEMPERATURE LIMITS API SPRING BODY INCONEL CS - WC6 STAINLESS STEEL CARBON STEEL TUNGSTEN SS - CF8M CARBON STEEL - WCB SET PRESSURE - PSIG SET PRESSURE - BAR G ORIFICE P (All dimensions in inches) Size Rating A B C* D E F G H Wt (ins) lbs (kg) 4 x x / (115) 300 x / (115) 600 x / (122) 900 x / (187) * If a gag is fitted, add 0.5 ins. If a lever is fitted, add a maximum of 3.5 inch. (Only if flange rating is 600# or less.) For certified height (c), consult facry. Vent hole H on bellows valves only. 39

41 VALVE SELECTION TABLE P 6.38 ins mm 2 Flanges ANSI Key Valve size No. inlet x outlet Inlet Outlet Body (ins) Mat l -76 F -450 F -60 C -268 C Max. Set Pressure (psig) and Temperature Limits -21 F -75 F -30 C -59 C 100 F -20 F 38 C -29 C 450 F 800 F 1000 F 232 C 427 C 538 C Max. Back Pressure (psig) Conventional Valve Balanced Bellows Valve 1 4 x 6 150#RF 150#RF x 6 300#RF 150#RF WCB 3 4 x 6 600#RF 150#RF x 6 900#RF 150#RF x 6 300#RF 150#RF x 6 600#RF 150#RF WC x 6 900#RF 150#RF x 6 150#RF 150#RF x 6 300#RF 150#RF CF8M x 6 600#RF 150#RF RF=Raised Face Minimum set pressure limits for metal seat trim Conventional 4 psig Bellows - Gas 13 psig Bellows - Liquid 24 psig* Conventional 1.5 psig (Inverted) *For liquid bellows valves below this pressure refer facry Note: Soft seated valves require a minimum set pressure of 15 psig. High Pressure Version. Certain spring materials can not be used in the low pressure version of the valve, up the maximum pressure. If the required set pressure with your choice of spring material is in excess of the figure shown in the table either choose another material or add H the valve accessories select an high pressure valve. Inlet Max. Set Spring Material (pressures in Psig) Orifice rating Pressure Psig Carbon st. 316 SS Tungsten 17/4PH 17/4PH NACE Inconel X750 P 150# 285 n/a n/a n/a n/a n/a n/a P 300# 525 n/a 350 n/a n/a P 600# 1000 n/a 640 n/a n/a 336 n/a 40

42 VALVE SELECTION GUIDE Q in mm 2 TEMPERATURE LIMITS API SPRING BODY CS - WC6 STAINLESS STEEL CARBON STEEL TUNGSTEN SS - CF8M CARBON STEEL - WCB SET PRESSURE - PSIG SET PRESSURE - BAR G ORIFICE Q (All dimensions in inches) Size Rating A B C* D E F G H Wt (ins) lbs (kg) 6 x x / (165) 300 x / (165) 600 x / (181) * If a gag is fitted, add 0.5 ins. If a lever is fitted, add a maximum of 3.5 inch. (Only if flange rating is 600# or less.) For certified height (c), consult facry. Vent hole H on bellows valves only. 41

43 VALVE SELECTION TABLE Q in mm 2 Flanges ANSI Key Valve size No. inlet x outlet Inlet Outlet Body (ins) Mat l -76 F -450 F -60 C -268 C Max. Set Pressure (psig) and Temperature Limits -21 F -75 F -30 C -59 C 100 F -20 F 38 C -29 C 450 F 800 F 1000 F 232 C 427 C 538 C Max. Back Pressure (psig) Conventional Valve Balanced Bellows Valve 1 6 x 8 150#RF 150#RF x 8 300#RF 150#RF WCB x 8 600#RF 150#RF x 8 300#RF 150#RF WC x 8 600#RF 150#RF x 8 150#RF 150#RF x 8 300#RF 150#RF CF8M x 8 600#RF 150#RF RF=Raised Face Minimum set pressure limits for metal seat trim Conventional 4 psig Bellows - Gas 13 psig Bellows - Liquid 23 psig* Conventional 1.5 psig (Inverted) *For liquid bellows valves below this pressure refer facry Note: Soft seated valves require a minimum set pressure of 15 psig. High Pressure Version. Certain spring materials can not be used in the low pressure version of the valve, up the maximum pressure. If the required set pressure with your choice of spring material is in excess of the figure shown in the table either choose another material or add H the valve accessories select an high pressure valve. Inlet Max. Set Spring Material (pressures in Psig) Orifice rating Pressure Psig Carbon st. 316 SS Tungsten 17/4PH 17/4PH NACE Inconel X750 Q 150# 165 n/a 109 n/a n/a 117 n/a Q 300# 300 n/a 109 n/a Q 600# 600 n/a 109 n/a

44 VALVE SELECTION GUIDE R in mm 2 TEMPERATURE LIMITS API SPRING BODY STAINLESS STEEL CARBON STEEL TUNGSTEN SS - CF8M CARBON STEEL - WCB SET PRESSURE - PSIG CS - WC SET PRESSURE - BAR G ORIFICE R (All dimensions in inches) Size Rating A B C* D E F G H Wt (ins) lbs (kg) 6 x x / (168) 300 x / (168) 6 x x / (211) 600 x / (222) * If a gag is fitted, add 0.5 ins. If a lever is fitted, add a maximum of 3.5 inch. (Only if flange rating is 600# or less.) For certified height (c), consult facry. Vent hole H on bellows valves only. 43

45 VALVE SELECTION TABLE R in mm 2 Flanges ANSI Key Valve size No. inlet x outlet Inlet Outlet Body (ins) Mat l -76 F -450 F -60 C -268 C Max. Set Pressure (psig) and Temperature Limits -21 F -75 F -30 C -59 C 100 F -20 F 38 C -29 C 450 F 800 F 1000 F 232 C 427 C 538 C Max. Back Pressure (psig) Conventional Valve Balanced Bellows Valve 1 6 x 8 150#RF 150#RF x 8 300#RF 150#RF WCB 3 6 x #RF 150#RF x #RF 150#RF x 8 300#RF 150#RF WC6 6 6 x #RF 150#RF x 8 150#RF 150#RF x 8 300#RF 150#RF CF8M 9 6 x #RF 150#RF x #RF 150#RF RF=Raised Face Minimum set pressure limits for metal seat trim Conventional 4 psig Bellows - Gas 13 psig Bellows - Liquid 25 psig* Conventional 1.5 psig (Inverted) *For liquid bellows valves below this pressure refer facry Note: Soft seated valves require a minimum set pressure of 15 psig. High Pressure Version. Certain spring materials can not be used in the low pressure version of the valve, up the maximum pressure. If the required set pressure with your choice of spring material is in excess of the figure shown in the table either choose another material or add H the valve accessories select an high pressure valve. Inlet Max. Set Spring Material (pressures in Psig) Orifice rating Pressure Psig Carbon st. 316 SS Tungsten 17/4PH 17/4PH NACE Inconel X750 6R8 150# 100 n/a 73 n/a n/a 90 n/a 6R8 300# 100 n/a 73 n/a n/a 90 n/a 6R10 300# 230 n/a 73 n/a R10 600# 300 n/a 190 n/a n/a 180 n/a 44

46 VALVE SELECTION GUIDE T in mm 2 TEMPERATURE LIMITS API SPRING BODY STAINLESS STEEL CARBON STEEL TUNGSTEN SS - CF8M CARBON STEEL - WCB SET PRESSURE - PSIG CS - WC SET PRESSURE - BAR G ORIFICE T (All dimensions in inches) Size Rating A B C* D E F G H Wt (ins) lbs (kg) 8 x x / (300) 300 x / (310) * If a gag is fitted, add 0.5 ins. If a lever is fitted, add a maximum of 3.5 inch. (Only if flange rating is 600# or less.) For certified height (c), consult facry. Vent hole H on bellows valves only. 45

47 VALVE SELECTION TABLE T in mm 2 Flanges ANSI Key Valve size No. inlet x outlet Inlet Outlet Body (ins) Mat l -76 F -450 F -60 C -268 C Max. Set Pressure (psig) and Temperature Limits 1 8 x #RF 150#RF WCB 2 8 x #RF 150#RF x #RF 150#RF WC x #RF 150#RF CF8M 5 8 x #RF 150#RF F -75 F -30 C -59 C 100 F -20 F 38 C -29 C 450 F 800 F 1000 F 232 C 427 C 538 C Max. Back Pressure (psig) Conventional Valve Balanced Bellows Valve RF=Raised Face Minimum set pressure limits for metal seat trim Conventional 4 psig Bellows - Gas 13 psig Bellows - Liquid 18 psig* Conventional 1.5 psig (Inverted) *For liquid bellows valves below this pressure refer facry Note: Soft seated valves require a minimum set pressure of 15 psig. High Pressure Version. Certain spring materials can not be used in the low pressure version of the valve, up the maximum pressure. If the required set pressure with your choice of spring material is in excess of the figure shown in the table either choose another material or add H the valve accessories select an high pressure valve. Inlet Max. Set Spring Material (pressures in Psig) Orifice rating Pressure Psig Carbon st. 316 SS Tungsten 17/4PH 17/4PH NACE Inconel X750 T 150# 65 n/a n/a n/a n/a n/a n/a T 300#

48 PRESSURE ADJUSTMENT Each valve is facry set and normally would not need any pressure adjustment; however, if the occasion arises, the following procedures apply: ASME If the valve is ASME stamped (UV)(NB), repairs must be carried out by an ASME authorised repair company, i.e. one holding either the (UV) or (VR) stamp Test rig It is normally desirable remove the valve from the plant and use a suitable test rig, specifically designed for safety relief valves. Range Each spring has a definite range, the limits of which should not be exceeded. These should be checked with the facry, since if a set pressure change is required, it may be necessary obtain a new spring. Should the set pressure be changed it is important ensure that the valve will still have sufficient capacity under the new service conditions. Procedure 1) Remove the cap (3). This exposes the compression screw (12). 2) Slacken the locknut (13). 3) Introduce pressure the valve inlet. The spring pressure and consequently the valve set pressure may be increased or decreased by turning the compression screw. Clockwise - increases set pressure Anti-clockwise - decreases set pressure Check against a calibrated pressure gauge. 4) Re-tighten the locknut and refit the cap. Replace cap gasket if damaged. 5) Check seat leakage (see page 49/50). COLD DIFFERENTIAL TEST PRESSURE When setting a valve intended for use at high temperature on a test rig using a test fluid at ambient temperatures, it is necessary set the valve at a slightly higher pressure, so that it will open at the correct set pressure under relieving conditions. The necessary allowance is shown in the following table. Relieving Relieving % Increase in set temperature temperature pressure at ambient Centigrade Fahrenheit temperature WB, B + C Series Up 121 C Up 250 F None >121 C 316 C >250 F 600 F 1 >316 C 427 C >600 F 800 F 2 >427 C 538 C >800 F 1000 F 3 D Series Up 100 C Up 212 F None >100 C 150 C >212 F 302 F 2 >150 C 260 C >302 F 500 F 3 47

49 BLOWDOWN RING SETTING The blowdown adjustment is achieved by means of a single blowdown ring. By reducing the blowdown gap, blowdown is increased. By increasing the blowdown gap, blowdown is decreased. Blowdown is defined as the difference between the set pressure of the valve and the reseating pressure. Important It is important reset the blowdown ring the correct position after maintenance has been carried out on the valve. Method Note: It is dangerous adjust the blowdown ring when the valve is under pressure, unless a suitable test gag is fitted prevent inadvertent valve opening 1) Removing the setting screw in the body permits access the blowdown ring. 2) Close the blowdown gap until the ring is uching the face of the disc (turn the ring from left right). 3) Consult the chart in the maintenance manual determine the correct blowdown ring setting, or consult the facry. 4) Wind back the blowdown ring the right number of notches establish the correct position (count the number of notches or serrations on the outside of the blowdown ring). 5) Relocate the locking pin in the notches provided on the outside diameter of the blowdown ring. 6) Tighten up the setting screw, ensuring that an undamaged gasket is in place. 48

50 SEAT TIGHTNESS / SEAT LEAKAGE TESTING (in accordance with API 527) Described here are methods of determining the seat tightness of metal and soft-seated pressure relief valves, including those of conventional, bellows and pilot-operated designs. The maximum acceptable leakage rates are defined for pressure relief valves with set pressures from 15 Psig 6,000 Psig. If greater seat tightness is required, the purchaser shall specify it in the purchase order. The test medium for determining the seat tightness - air, steam or water - shall be the same as that used for determining the set pressure of the valve. For dual-service valves, the test medium - air, steam or water - shall be the same as the primary relieving medium. To ensure safety, the procedures outlined shall be performed by persons experienced in the use and functions of pressure relief valves. Test apparatus for air seat tightness Tube 5 16" o.d. x 0.035" wall 1 2" TESTING WITH AIR A1 Test apparatus A test arrangement for determining seat tightness with air is shown opposite. Leakage shall be measured using a tube with an outside diameter of 5/16 inch and a wall thickness of inch. The tube end shall be cut square and smooth. The tube opening shall be 1 2 inch below the surface of the water. The tube shall be perpendicular the surface of the water. A2 Test medium The test medium shall be air (or nitrogen) near ambient temperature. A3 Test configuration The valve shall be vertically mounted on the test stand and the test apparatus shall be attached the valve outlet, as shown opposite. All openings - including but not limited caps, drain holes, vents, and outlets shall be closed. A4 Test pressure For a valve whose set pressure is greater than 50 Psig, the leakage rate (in bubbles per minute) shall be determined with the test pressure at the valve inlet held at 90% of the set pressure. For a valve set at 50 Psig or less, the test pressure shall be held at 5 Psig less than the set pressure. A5 Leakage test Before the leakage test, the set pressure shall be demonstrated and all valve body joints and fittings should be checked with a suitable solution ensure that all joints are tight. Air receiver API 527 Air Leakage Rates Cover plate Before the bubble count, the test pressure shall be applied for the following times: Valve size Time Up 2ins 1 min 3ins 4ins 2 min 6ins and above 5 min The valve shall then be observed for leakage for at least 1 minute. A6 Acceptance criteria For a valve with a metal seat, the leakage rate in bubbles per minute shall not exceed the appropriate value in chart opposite. For a softseated valve, there shall be no leakage for 1 minute (0 bubbles per minute). 49

51 SEAT TIGHTNESS / SEAT LEAKAGE TESTING (in accordance with API 527) TESTING WITH STEAM S1 Test medium The test medium shall be saturated steam. S2 Test configuration The valve shall be vertically mounted on the steam test stand. S3 Test pressure For a valve whose set pressure is greater than 50 Psig, the seat tightness shall be determined with the test pressure at the valve inlet held at 90% of the set pressure. For a valve set at 50 Psig or less, the test pressure shall be held at 5 Psig less than the set pressure. S4 Leakage test Before starting the seat tightness test, the set pressure shall be demonstrated and the test pressure shall be held for at least 3 minutes. Any condensate in the body bowl shall be removed before the seat tightness test. Air (or nitrogen) may be used dissipate condensate. After any condensate has been removed, the inlet pressure shall be increased the test pressure. Tightness shall then be checked visually using a black background. The valve shall then be observed for leakage for at least 1 minute. S5 Acceptance criteria For both metal and soft-seated valves, there shall be no audible or visible leakage for 1 minute. TESTING WITH WATER IMPORTANT ALL LIQUID TRIM VALVES MUST BE TESTED ON WATER. OTHERWISE SET PRESSURES AND LEAKAGE RATE RESULTS WILL BE FALSE. W1 Test medium The test medium shall be water near ambient temperature. W2 Test configuration The valve shall be vertically mounted on the water test stand. W3 Test pressure For a valve whose set pressure is greater than 50 Psig, the seat tightness shall be determined with the test pressure at the valve inlet held at 90% of the set pressure. For a valve set at 50 Psig or less, the test pressure shall be held at 5 Psig less than the set pressure. W4 Leakage test Before starting the seat tightness, the set pressure shall be demonstrated and the outlet body bowl shall be filled with water. The pressure gauge shall be allowed stabilise with no visible flow from the valve outlet. The inlet pressure shall then be increased the test pressure. The valve shall then be observed for 1 minute at the test pressure. W5 Acceptance criteria For a metal-seated valve whose inlet has a nominal pipe-size of 1 inch or larger, the leakage rate shall not exceed 10 cubic centimetres per hour per inch of nominal inlet size. For a metal-seated valve whose inlet has a nominal pipe size of less than 1 inch, the leakage rate shall not exceed 10 cubic centimetres per hour. For soft-seated valves, there shall be no leakage for 1 minute. IMPORTANT: Test rig cleanlines is vital avoid contamination and damage the safety relief valve seat surfaces. 50

52 Safeflo - Safety and thermal relief valves 1 Accessories 2 High performance springs 3 Guiding surfaces 4 Trim 51

53 FEATURES AND BENEFITS Design verification The: B Series (gas/vapour) C Series (liquid) D Series (gas, liquid and steam) have been developed on Birkett s in-house, extensive mass flow test facility. Simplified maintenance For the flanged version, a slip on inlet flange makes it easier realign in existing pipework after servicing. Interchangeable parts Valves can easily be modified from gas liquid or liquid gas with the minimum number of parts. The D Series is certified for all media without modification. Safe and reliable Proven dependability ensures safe and reliable performance. Cryogenic and oxygen service Birkett s state-of-the-art clean room and vapour degreasing facilities ensure compliance with the stringent demands of cryogenic and oxygen applications. (The D Series is not available for cryogenic service.) 1. Wide range of accessories Available comply with international codes and suit system requirements. 2. High performance springs Safety relief valve springs are specially designed guarantee set point repeatability. 3. Guiding surfaces The material selection of guiding components, gether with self aligning disc pivot points, ensures correct alignment and no galling of guiding surfaces. 4. Trim B/C Series valves have been designed with metal trim give optimum performance at higher pressures. The 7D is available with a soft seat or metal seat, while the 6D is metal seated only. Balanced pisn Available on the 7D Series counter the effects of variable back pressure. Material selection A wide range of materials are offered, including non-ferrous for low temperature and oxygen service, and exotic alloys specified for the chemical and process industries. 52

54 B/C SERIES THERMAL RELIEF VALVES Cryogenic versions of the B and C Series are available ITEM PART CARBON STEEL STAINLESS STEEL 1 Body SA 216-WCB CARB ST SA 351-CF8M ST ST 3 Cap ASTM A ASTM A L 4* Nozzle 316 ST ST 316 ST ST 5* Disc 316 ST ST 316 ST ST 6* Disc holder SA564 17/4 (33HRC) SA564 17/4 (33HRC) 9 Guide SA351-CF8M ST ST SA351-CF8M ST ST 11 Lower spring plate ASTM A ASTM A Adjusting screw ASTM A ASTM A Locking nut ASTM A L ASTM A L 22* Spring C.S. ALUMINIUM COATED ASTM A * Cap gasket ST-706 ST * Ball AISI 440C ST ST AISI 440C ST ST 32 Upper spring plate ASTM A ASTM A Data plate 321 ST ST 321 ST ST 34 Hammer drive screw ELECTRO BRASSED CS ASTM A L 76 Capscrew ST ST BS6105 A2-70 ST ST BS6105 A Flange SA 105 CARB ST SA 182-F316 ST ST * Recommended spares. 53

55 D SERIES THERMAL RELIEF VALVES ITEM PART CARBON STEEL STAINLESS STEEL 1 Body SA 216-WCB CARB ST SA 351-CF8M ST ST 3 Cap SA 216-WCB CARB ST SA 351-CF8M ST ST 4* Nozzle 316 ST ST 316 ST ST 5* Disc 316 ST ST 316 ST ST 9 Guide 17/4 PH ST ST 17/4 PH ST ST 10 Spindle 316 ST ST 316 ST ST 12 Adjusting screw ASTM A ASTM A Locking nut ASTM A L ASTM A L 22* Spring C.S. ALUMINIUM COATED ASTM A * Cap gasket ST-706 ST Body gasket ST-706 ST Data plate 321 ST ST 321 ST ST 34 Hammer drive screw ELECTRO BRASSED CS. ASTM A L 75 Grub screw ASTM A L ASTM A L 85 Inlet flange SA 105 CARB ST SA 182-F316 ST ST 147 Flange nut SA564 17/4 (33HRC) SA564 17/4 (33HRC) 188 Adjusting screw bush VIRGIN PTFE VIRGIN PTFE 235 Spring end plate ASTM A ASTM A * Recommended spares. 54

56 ACCESSORIES Packed lever The design of the packed lever assembly ensures that leakage does not occur when the valve is open or when back pressure is present. Balanced pisn This option is only available on the 7D Series valves. It is designed overcome the effects of variable back pressure. Open lever design is not available on Safeflo valves. Gag Screw Sealing Plug Test gag The test gag is used prevent the safety valve from lifting. This is mainly used when carrying out a hydrostatic test on the system, during commissioning. The test gag must never be left in the valve. The sealing plug should be fitted at all other times, allowing the valve operate freely. Pressure adjustment: refer page 47. Cold differential test pressure: refer page 47. Seat tightness/seat leakage testing: refer page 49/50. Minimum pressure setting: B Series, normal attitude 10 Psig. C Series, normal attitude 15 Psig. 7D Series, normal attitude 5 Psig. 6D Series, normal attitude 740 Psig. Lower pressures are NOT available by inverting the valve. 55

57 SAFEFLO - SAFETY AND THERMAL RELIEF VALVE Different types: There are two different types, both are conventional designs. B Series - Safety and thermal relief valve, gas duty. C Series - Safety and thermal relief valve, liquid duty. D Series - Safety and thermal relief valve, gas, steam and liquid duty. All are certified in accordance with ASME Code Section VIII. SAFEFLO FIGURE NUMBERING SYSTEM / / Orifice Area in ** ** ** ** * * Accessories C Screwed cap P Packed lever G Test gag F Ferrule (Government ring) S Special feature B Balanced pisn R Soft seat Valve series B Gas vapour C Liquid D Gas, steam and liquid Connection size 1 1 2" x 1" orifice 1, 2, 6 or " x 1" orifice 1, 2, 6 or 7 3 1" x 1 1 2" orifice " x 2" orifice 4 screwed only 5 1" x 1" orifice 1, 2, 6 or 7 Inlet connection type A BSP Tr male screwed B BSP female screwed C API male screwed D API female screwed 1 ANSI 300/600 RF flange 2 ANSI 900/1500 RF flange** 3 ANSI 2500 RF flange** 7 ANSI 150 RF flange O Special** Outlet connection type E BSP female screwed F API female screwed 1 ANSI 150 RF flange 2 ANSI 300 RF flange** O Special** Trim - nozzle and disc material 1 Stainless steel PH 17/4 2 Stainless steel Hastelloy B** 5 Stainless steel 316 stellited** 6 Monel 400** 7 Stainless steel 304** O Special** Spring material A Aluminium Coated CS 2 Stainless steel Tungsten alloy 9 Hastelloy B** T Aluminium Coated Tungsten Z Inconel X750 O Special** Body material 1 Carbon steel WCB 2 Carbon steel WCB NACE 3 Stainless steel CF8M NACE 4 Stainless steel CF8M O Special** *Available on D Series only. **Not available on D Series. Available on 7D only. 56

58 B/C SERIES DIMENSIONS Female screwed Male screwed Flanged Note: A packed lever version and gagging facility are also available. Sizes (ins) inlet & outlet Inlet & Outlet connection Orifice No. Max pressure up Dimensions ins (mm) 100 F (Psig) A B C* D Inlet Outlet Weight lbs (kg) 1/2 x 1 Screwed Female 2 (64) (219) (43) (4) 3/4 x 1 x Female 2 (64) (219) (43) (4) 1 x (64) (219) (43) (4) 1 x 11/ (83) (349) (60) (12) 11/2 x (83) (349) (60) (12) 1/2 x 1 Screwed Male 2 (65) (19) (238) (43) (4) 3/4 x 1 x Female 2 (65) (19) (238) (43) (4) 1 x (59) (25) (238) (43) (4) 1 x 11/ (83) (25) (375) (60) (12) 11/2 x (83) (29) (378) (60) (12) 3/4 x 1, # x 150# x 1 (117) (25) (260) (95) (7.25) 1/2 x 1, 3 /4 x 1, /600# x 150# x 1 (117) (35) (260) (95) (7.25) 1/2 x 1, 3 /4 x 1, /1500# x 300# x 1 (117) (46) (264) (95) (9) 3/4 x 1, 1 x # x 300# (121) (51) (267) (95) (9) 1 x 11/2 150# x 150# (143) (25) (425) (140) (18) 1 x 11/2 300/600# x 150# (143) (35) (425) (140) (18) 1 x 11/2 900/1500# x 300# (143) (46) (425) (140) (18) 1 x 11/2 2500# x 300# (143) (51) (425) (140) (18) *If a gag screw is fitted, add 2 ins (51mm) dimension C for orifice nos. 1 & 2 only. *If a packed lever is fitted, add ins (44mm) dimension C for orifice nos. 1 & 2 only. Orifice sizes: refer sizing section, page 84. Minimum set pressure B Series (Gas) = 10 Psig (0.7 Barg) C Series (Liquid) = 15 Psig (1.035 Barg) Orifice No.1 = 1480 Psig (102 Barg) Temperature range (with suitable material selection) -320 F 1,000 F (-196 C 538 C) 425 Psig with 300# outlet 57

59 D SERIES DIMENSIONS Female screwed Male screwed Flanged Note: A packed lever version and gagging facility are also available. Sizes (ins) inlet & outlet Inlet & Outlet connection Orifice No. Max pressure up Dimensions ins (mm) 100 F (Psig) A B C D Inlet Outlet If a packed lever is fitted, add ins (27mm) dimension C for orifice 7 only. If a gag screw is fitted, add ins (10mm) dimension C for orifice 7 only. If a balanced pisn is fitted, add ins (54mm) dimension C for orifice 7 only. If a gagged balanced pisn is fitted, add ins (64mm) dimension C for orifice 7 only. Orifice sizes: refer sizing section, page 84. Minimum set pressure 7D (Gas, Steam or Liquid) = 5 Psig (0.35 Barg) 6D (Gas, Steam or Liquid) = 740 Psig (51 Barg) Temperature range (with suitable material selection) 6D and 7D -51 F 500 F (-46 C 260 C) Weight lbs (kg) 1/2 x 1 Screwed /4 x 1 Female x Female (44) (189) (55) (4) 1 x 1 Screwed Male x Female (43) (19) (209) (55) (4) 3/4 x ANSI 600# x 150# 6 1 x 1 (117) (41) (262) (95) (6.5) 1/2 x 1 Screwed /4 x 1 Female x Female (44) (189) (55) (4) 1 x 1 Screwed Male x Female (43) (19) (209) (55) (4) 3/4 x 1 ANSI 150# x 150# x 1 ANSI 300# x 150# (117) (41) (262) (95) (6.5) 58

60 Safeset - Pilot operated safety relief valve 1 Close differential pressure setting 15 State-of-the-art pisn seals 2 Close blowdown and overpressure lerance 14 Two part pisn assembly 3 Non-flowing pilots 4 Integral pilot filter 5 All stainless steel pilots, dome, tubes and fittings 6 Adjustable orifice areas 7 Full lift capability 8 Soft seat 9 Enhanced seat tightness 10 Unique full nozzle design 11 API 526 compliant 13 Dual outlet option 12 Integral sensing of pilot 59

61 FEATURES AND BENEFITS Close system operating pressure The system operating pressure can be much closer the set pressure on a pilot operated valve than with a standard spring loaded safety relief valve. System pressures in the region of 95% 98% of set pressure are often accommodated. Tolerates high inlet pressure loss High inlet pressure losses due difficult inlet piping systems can be accommodated by remote sensing the pilots, hence trouble free operation can be assured. 1. Close differential pressure setting Pop acting pilot valves are quick acting and hence there is no delay between the pilot and the main valve opening pressures. Modulating valves inherently have a delay, which is nominally 2%. This ensures the pilot is not leaking when the system pressure is close the set pressure. 2. Close blowdown and overpressure lerance Pop action pilots can be adjusted give zero overpressure and a blowdown typically equal 3% of set pressure. 3. Non flowing pilot Safeset pilots are of the non flowing design. The risk of freezing due pressure drops in the flowing medium is removed. Additionally, dirt particles are not transported the pilot as the medium is static. This improves life in service and ensures trouble free operation. 7. Full lift capability Pilot valves will maintain full lift against high levels of back pressure. Unlike spring loaded valves, which would need either differential setting or the addition of balanced bellows. 8. Soft seat Safeset pilots and main valves are soft seated give optimum leak tightness. Materials are available for a wide range of duties. Maintenance is simplified as seat lapping is reduced. 9. Enhanced seat tightness The main valve is pisn operated. The pisn area is in excess of 30% larger than the seat bore area. This ensures the seat closing force is always at least 30% greater than the seat opening force for all pressures, right up the set point. This produces more effective seat tightness, reducing the possibility of seat leakage. A spring loaded valve will have maximum seat clamping force when there is no system pressure. As the system pressure approaches the set point, the upward acting valve opening force approaches the closing force generated by the spring, hence the clamping force approaches zero and seat leakage may occur. A pilot valve with a 30% differential pisn design will maintain a 30% seat clamping force right up the set point, ensuring maximum seat tightness. 4. Integral pilot filter Safeset pilots are fitted with integral filters. 5. Stainless steel Safeset pilots, domes, tubes and fittings, pisns and nozzles are made from stainless steel as a minimum, i.e. all process wetted parts. This reduces the risk of oxides contaminating seals and hence prolongs their life in service. 6. Adjustable orifice areas The standard range of single outlet main valves consists of 8 body sizes, which by simple adjustment accommodates all 21 standard orifice sizes. This allows for easy adjustment should service conditions dictate a change in required orifice area. Seat clamping = force Valve closing force Valve opening force 60

62 10. Unique full nozzle design The nozzle is a patented push-in design, held in position with a locking ring. Being of the full nozzle design, it reduces mechanical and thermal stresses at the seat, reduces inlet pressure losses, increases the discharge co-efficient and allows for lower specification body materials on corrosive duties. 11. API 526 compliant Fully conforms the latest edition of API 526 for pressure/ temperature ratings and over flange dimensions for pilot valves. 14. Two part pisn-disc assembly This gives a reduced guiding geometry, keeping the size of the components within the body bowl a minimum, thus increasing the effective discharge area through the valve outlet. 15. State of the art pisn seals and bearing rings Reduce friction and galling of materials at the guide and pisns surfaces essential for modulating pilots. 12. Integral sensing Safeset pilots are sensed from the nozzle, giving a compact design and accurate pressure sense from within the flow stream. Remote sensing for difficult inlet piping systems is recommended. 13. Dual outlet option The 8 inch valve is also available with a dual outlet (see below). DUAL OUTLET / FULL BORE PILOT VALVE This valve is suitable for extremely high capacity duties. It achieves maximum discharge capacities by having a full bore 8 inch inlet with an available discharge area of sq.in. and two opposing 10 inch outlets, which can assist with reaction force problems. Available with all Pilot Types 2, 4, and 8. 61

63 MODE OF OPERATION Safeset consists of a separate pilot valve connected a main valve via a sensing pipe. This pipe senses the inlet pressure within the main valve nozzle and provides the pressure signal the pilot. Pilot valve The pilot valve controls the discharge of fluid through the main valve by responding accurately the system pressure. All Birkett pilots are of a non flowing design, which means there is an absence of system flow through the pilot during the relief cycle. Main valve The main valve conforms the latest version of API 526 Pressure/Temperature ratings and face face dimensions. It has 21 orifice variants in just 8 inlet x outlet body sizes. Safeset is a differential pisn operated design, the opening is controlled by the pilot valve. The benefits of non flowing designs are that freezing of moisture-containing fluid and the carrying of particulate matter in the pilot are minimised, ensuring correct valve performance. PILOT VALVE TYPES Pop (Type 2) Controls the main valve in a rapid manner, it is either open or closed. Specifically for gas applications. Modulating (Types 4 and 8) The main valve is opened in a controlled manner, the over pressure is constantly monired and the opening of the main valve is proportionate the overpressure. BASIC OPERATION OF SAFESET Simply, the pilot valve is a very accurate springloaded safety valve, with two seats. At low system pressures, pressure from the system is fed from the inlet nozzle, through the sense line, past the lower pilot seat and in the main valve dome. The dome area is in excess of 30% larger than the seat bore area. This differential of areas ensures that the main valve remains closed. When the system pressure reaches the set point of the pilot, the lower pilot seat closes and the upper pilot seat opens, releasing the dome pressure the atmosphere. With no pressure above the pisn, the main valve opens. The reverse of this sequence of events occurs when system pressure falls and once again the main valve dome will be fed with system pressure, which in turn closes the main valve. 62

64 POP ACTION - TYPE 2 PILOT Pilot construction The pilot is essentially a spring loaded safety valve with blowdown adjustment which, during its operation, positions itself on one of two seats. The upper drain seat is used determine pilot set pressure, the lower feeding seat determines pilot blowdown. The valve disc is held on the soft upper drain seat by the setting spring, which also determines the pilot set pressure. This valve disc is connected via a spindle the lower feeding seat, which controls the system flow in the dome and which also controls the pilot blowdown. TO AND FROM MAIN VALVE DOME FEEDING SETTING SPRING DISC UPPER DRAIN SEAT EXHAUST SPINDLE The valve disc and lower feeding seat move gether; this action opens and closes each respective seat, thereby allowing the pilot control the operation of the main valve during the relieving cycle. LOWER FEEDING SEAT FILTER Pilot operation With pop action pilot operation, the main valve is either in the fully open or shut position. The operation is characterised by a distinct rapid pop action, which is evident at the opening of the main valve, followed by a positive re-seat action when the main valve closes. The re-seat pressure of the Type 2 pilot valve is adjustable externally, independently of the set pressure adjustment. This graph demonstrates pop action. When set pressure is reached, the pilot valve opens rapidly; this action de-pressurises the dome volume very quickly and the main valve opens. This is shown by the vertical (rising) line on the graph, illustrating that the main valve achieves its design lift at set pressure. The re-seating characteristic is equally positive: when the system pressure has fallen the pre-set pilot re-seat pressure, the pilot drain seat closes rapidly. This action allows the dome be repressurised very quickly, thereby closing the main valve completely. This is shown on the graph by the vertical (falling) line. 63

65 STAGES OF OPERATION - TYPE 2 PILOT Stage 1 System pressure below the pilot set pressure, dome pressurised, main valve closed. Stage 2 System pressure equal set pressure, drain seat opens, dome de-pressurises, main valve fully lifts with no overpressure. Stage 3 System pressure equal or greater than set pressure, dome pressure is atmospheric, main valve is fully open. Stage 4 System pressure falls equal the re-seat pressure, drain seat closes, feeding seat opens, dome is pressurised, main valve closes. Stage 5 System pressure below the pilot set pressure, dome pressurised, main valve closed and ready for next upset condition. Key Points Pilot Type 2 Pilot set pressure = Main valve set pressure. Main valve fully open at 0% overpressure. The pilot is non flowing. Adjustable blow-down feature. Integral filter fitted. Gas duty only. 64

66 MODULATING ACTION - TYPE 4 Pilot construction Modulating pilots are essentially diaphragm or pisn operated safety valves with a feedback pisn for fine control of the pressure in the dome. The Type 4 Pilot is used for pressures up 1480Psig DETECTOR DIAPHRAGM SETTING SPRING When the set pressure is reached the main valve opens in proportion the system pressure rise. This is achieved by the pilot controlling the dome pressure. The main valve will maintain a lift necessary discharge the system flow. As the system pressure increases, the main valve lift will change accommodate the new flow condition. As the system pressure falls, the main valve will begin close, finally closing at a pressure just below the set pressure. The diaphragm senses the system pressure and the feedback pisn senses the dome pressure. The combination of these pressures accurately provide a force balanced with the adjusting spring open/close the feeding/drain seats. This maintains dome pressure for accurate positioning of the main valve. FEEDBACK PISTON FEEDING FILTER FEEDING SEAT Type 4/1 Pilot ( Psig) DOME RETURN SPRING DRAIN DRAIN SEAT DETECTOR PISTON Type 4/2 Pilot ( Psig) Note: The Pilot Type 4 always drains the main valve outlet, and a back flow preventer should be fitted (see page 72). 65

67 MODULATING ACTION - TYPE 8 The Type 8 Pilot is similar the Type 4 Pilot except that instead of using a diaphragm lift the valve, the Type 8 Pilot uses a pisn. SETTING SPRING The pressure range for the Type 8 Pilot is 1480 Psig 6170 Psig. Note: The Type 8 Pilot always drains the main valve outlet, and a back flow preventer should be fitted (see page 72). FEEDBACK PISTON DOME DETECTER PISTON RETURN SPRING FEEDING SEAT DRAIN DRAIN SEAT FILTER FEEDING Type 8 Pilot PILOT OPERATION The action of the main valve may be characterised as modulating. In order achieve this the pilot accurately controls the pressure in the main valve dome which positions the main valve disc match the system upset flow condition; this will then control the system pressure. Effective pilot operation requires a small overpressure above the set pressure, achieve full design lift of the main valve and a small pressure drop re-seat the main valve. A typical modulating performance is shown in the graph opposite. The overpressure as a percentage of set pressure will vary with the system flow requirement; this means that an infinite number of relieving cycles can occur within the limits shown. The valve lift will, however, always be in proportion the rise in system pressure, ensuring a safe stable relief cycle. 66

68 STAGES OF OPERATION - TYPES 4 AND 8 Type 4 & 8 Pilots are fully modulating. They are intended for use with gas, liquid and mixed phase fluids. Both types are non flowing designs. STAGE 1 System pressure below set pressure The feeding seat remains open with the drain seat closed. This maintains equal pressures in the dome and the system. The main valve is closed, held tightly against the nozzle. Pilot Valve Drain STAGE 2 System pressure approaches set pressure When the system pressure approaches the set pressure the feeding seat closes. The drain seat remains closed and the main valve is closed. The pressure in the dome is now controlled by the inlet system pressure acting against the pilot diaphragm/pisn and the dome pressure acting on the feed back pisn. The combination of these two forces controls the opening of the drain seat, thereby controlling the dome pressure and hence the main valve lift. When the drain seat opens it discharges a small volume of fluid from the dome. At no time is the drain seat continually flowing. It drains in short bursts. P STAGE 3 System pressure reaches set pressure As the system pressure gradually rises the set pressure, the dome pressure gradually falls approximately 30%. Due the differential size, p and botm of the pisn, the main valve opening and closing forces are now in equilibrium. 67

69 STAGE 4 System pressure above set pressure As the system pressure increases above the set pressure, modulation occurs with the main valve opening an amount sufficient maintain system flow rate. This is brought about by the increased system pressure acting against the pilot diaphragm/pisn re-open the drain seat. The dome pressure is reduced further, allowing the main valve open. The reduced dome pressure now acting on the feedback pisn produces a lower upward force and the adjusting spring closes the drain seat. The above actions cycle in very small increments and hence give the modulating effect. STAGE 5 Main valve fully open The main valve will be fully open before the system pressure reaches 110% of the set pressure. STAGE 6 Main valve closes When the system upset condition has ended, the system pressure will begin fall. The reduced system pressure acting on the pilot diaphragm/pisn will cause the feeding seat reopen. This will increase the dome pressure and the main valve will begin close. The feeding seat will close as the dome pressure increases due the feedback pisn effect. This cycle will repeat as the system pressure is further reduced. The main valve will close with a progressive action. When the system pressure reaches approximately 97% of set pressure the main valve will be closed. Key points Pilot Types 4 and 8 Pilot set pressure is when the drain seat first opens. Main valve discharge maintains the system pressure at its respective flow condition, thereby achieving fully modulating action. The pilot valve is firmly closed when the main valve closes. Integral filter fitted. 68

70 TECHNICAL SPECIFICATION - PILOT VALVE Valve type Pilot action Pop Modulating Modulating Fluid Gas Gas, Liquid Gas, Liquid Dual Phase Dual Phase Overpressure 0% <10% <10% Blowdown 3-10%* <3% <3% Adjustable Fixed Fixed Pilot/main valve set pressure differential 0% 5% 2% Max back pressure Built up and Superimposed 70% 70% 70% Back pressures in excess of these limits can be accommodated - consult facry Pressure (Psig) range (Barg) High pressure pilots are available - consult facry Temp. range (deg F) (deg C) Accessories are available for cryogenic and high temperature applications - consult facry *Unless otherwise required or specified, the type 2 Pilot will be facry set for 5% blowdown. Type 2 Pilot must have the exhaust vent open atmosphere or piped a safe area. Types 4 and 8 Pilots always have their exhaust vents connected in the main valve outlet. MAIN VALVE - SOFT GOODS Material Temperature Pressure range degf (degc) Psig (Barg) Main valve seat St St filled PTFE -50/500 (-46/+260) Up 1480 (102) PEEK -85/500 (-65/+260) Over 1480 (102) Vin -4/400 (-20/+205) Up 1480 (102) Buna-N -50/248 (-46/+120) Up 1480 (102) Polyurethane -65/300 (-54/+150) 400/1480 (27.6/102) Main valve seat (NACE) PEEK -85/500 (-65/+260) Over 1480 (102) Vin -4/400 (-20/+205) Up 1480 (102) Polyurethane -65/300 (-54/+150) 400/1480 (27.6/102) Gaskets Carbon Fibre -50/500 (-46/+260) All pressures Laminated graphite -50/500 (-46/+260) All pressures PILOT VALVE - MATERIALS Material Temperature degf (degc) Body Bonnet Spring Trim St St 316 All St St 316 All St St 316 All St St 316 All Pilot seat and seals Buna-N -50/248 (-46/+120) Vin -4/400 (-20/+205) EPR -65/300 (-54/+150) EPDM -50/400 (-46/+205) Aflas -20/400 (-29/+205) Heating or cooling coils required above 400degF (205degC) and below -50degF (-46degC) Static seals Vin -4/400 (-20/+205) Up 1480 (102) AED Vin -4/400 (-20/+205) Over 1480 (102) Options: Buna-N, Aflas, Chemras, Kalrez 69

71 MATERIALS OF CONSTRUCTION - MAIN VALVE BODY MATERIAL CARBON STEEL STAINLESS STEEL Item Description ºC ºC ºC 1 Body SA 216 WCB SA 352 LCB SA 351 CF8M 2 Nozzle St. St. 316 St. St. 316 St. St Guide St. St. 17/4 St. St. 17/4 St. St. 17/4 4 Disc holder St. St. 316 St. St. 316 St. St Disc insert Vin * Vin * Vin * 6 Pisn St. St. 316 St. St. 316 St. St Locknut St. St. 316 St. St. 316 St. St Lift sp St. St. 316 St. St. 316 St. St Cover St. St. 316 St. St.316 St. St Retaining plate St. St. 316 St. St. 316 St. St Disc holder seal Vin * Vin * Vin * 12 Pisn seal Vin * Vin * Vin * 13&25 Guide rings Carbon/PTFE Carbon/PTFE Carbon/PTFE 14 Body stud A193/B7 A193/B8T A193/B8T 15 Body nut A194/2H A194/8T A194/8T 16 Lock ring St. St. 316 St. St. 316 St. St Spring St. St. 316 St. St. 316 St. St Body gasket Carbon fibre Carbon fibre Carbon fibre * 21 Guide seal Vin * Vin * Vin * 22 Nozzle seal Vin * Vin * Vin * 23 Retaining plate screw Vin * Vin * Vin* 24 Counter sunk screw St. St. 316 St. St. 316 St. St Fittings St. St. 316 St. St. 316 St. St Tubes St. St. 316 St. St. 316 St. St Drain plug HTS HOLO-KROME HTS HOLO-KROME ASTM A L Note: *Soft goods materials listed above are standard. For a full listing cover the temperature ranges of the body materials listed above, it is necessary refer the seals, gaskets, selection table on the previous page. Maximum temperature is limited by the seal material. Alternative materials and accessories are available, for NACE, high temperatures and cryogenic applications. 70

72 ACCESSORIES Back Flow Preventer Exterior Supply Filter 71

73 ACCESSORIES Back flow preventer High back pressures may exist in the outlet for various reasons such as common disposal systems. If this back pressure can be more than the inlet system operating pressure, the main valve could lift allowing reverse flow from the outlet inlet system. A back flow preventer is a two-way check valve, which is fitted in the dome line. It allows the highest pressure from either the inlet system or outlet system enter the dome, ensuring the main valve remains closed and prevents the possibility of reverse flow. All modulating pilots (Types 4 + 8) should be fitted with a back flow preventer. A back flow preventer should always be fitted if a vacuum can exist in the inlet pipework. When using back flow preventers with back pressure above 50% of the set pressure, the actual service conditions must be reviewed by the facry. External supply filter This unit protects the pilot valve when working under dirty flow stream conditions. All Safeset pilots are fitted with integral filters as standard; however, under conditions where there is likely be large amounts of particulate matter in the flow stream, a supply filter should be used. This unit is fitted in the pilot sensing pipe, upstream of the pilot, and is suitable for gas and liquid duty. It is removed easily for maintenance. Remote Pressure Sensing Sense Line (Max 100ft/30m including one 90 bend. Min inside diameter 0.254"/6mm) Remote pressure sensing Many codes and standards restrict the inlet pipework pressure loss 3% of the safety valve set pressure. There are occasions however, when the pipework loss is greater than this. In these instances the safety valve should always be connected for remote sensing. The valve is normally supplied with integral sensing; this means that the pilot senses pressure at the main valve nozzle entry. Under conditions of excessive system pressure loss, the valve, under flowing conditions, may cycle open and closed. This is due the pilot sensing a reduced (artificial) pressure. In order overcome this problem the valve should be sensed remotely. The pilot in this case should have its inlet connected directly the pressure source where the system pressure is stable and not flowing. The main valve nozzle will not contain a sensing tapping in this case. Excessive system pressure losses will also reduce the flow rate through the valve. This will be in proportion the absolute system pressure and must be taken in account when sizing the valve. Remote sensing will ensure that the pilot operated safety valve operates without cycling or chatter when high inlet pressure losses are encountered. 72

74 ACCESSORIES Heating or Cooling Coils Field Test Connecr Remote Pressure Sensing Heating or cooling coils High or low temperature duties may require the addition of coils act as heat exchangers either warm or cool the medium before it enters the pilot valve or main valve dome. This ensures that extremeties of temperature do not affect the operation of the safety valve. The use of such coils allows us use standard pilots on valves with inlet temperatures in the range of C (-320 F) 260 C (500 F). Field test connecr This provides verification of set pressure setting during normal system operation. The field test connecr is a two way check valve which is fitted in the sensing pipe and is an integral part of the pilot operated valve system. If this facility is required, it must be specified on the valve order. An external pressure supply needs be connected the check valve via an isolating valve and pressure gauge. The external pressure should be admitted slowly through the supply isolating valve. When the supply pressure is greater than the system pressure the check valve delivery seat will open and the system seat will close. Pressure can now be applied the pilot and dome. When set pressure is reached the pilot will open. N.B. Pop action pilots will pop open; this is the main valve set pressure. Modulating pilots will start vent from their drain seat; this will occur at approximately 2% below the main valve set pressure. The nameplate should be referred in order obtain the main valve set pressure. The main valve may open briefly with pop action pilots. 73

75 ACCESSORIES Others Similar the spring loaded safety relief valves (see page 15), pilot valves can be fitted with: Packed lift levers. Ferrules (government rings). Test gags (max pressure 1480 Psig). Available options Dual pilot assemblies. Dual pilot interlock system. Heated or unheated control cabinets. Dual outlet/full bore design. Differential pressure switch. Dual pilots If a process plant is running, it is earning a profit for its operar. Traditionally, when a valve required maintenance the plant had be shut down, resulting in reduced earning time. A solution this is install a second pilot on the main valve and install a simple system of ball valves or an interlocked changeover valve system, thus allowing one pilot be removed while the plant is still operating. We can offer either solution. 74

76 ACCESSORIES Remote unloader This device enables the main valve be opened remotely. It is a three way spool valve which can be operated electronically or pneumatically. The valve is mounted in the dome line and allows a free flow from the pilot in the dome. When remote operation is required, a signal (pneumatic or electrical) opens the exhaust vent of the spool valve and vents the dome, allowing the main valve open. The valve will normally be supplied mounted on the main valve with the dome connected directly the pilot. When the spool valve is energised the dome will vent directly atmosphere. Remote Unloader 75

77 SAFESET PILOT FIGURE NUMBERING SYSTEM P / Inlet diameter 1-8" Orifice designation D-T X = 8" x 10" x 10" full bore Outlet diameter 2" - 10" Pilot description 2 Pop action, gas 4 Modulating, LP 8 Modulating, HP ANSI flange rating x x x x x x 300 A 600 x 300 B 1500 x 600 C 2500 x 600 O Special Flange type 1 ANSI RF x RF 2 ANSI RTJ x RF O Special Main valve body code 1 Carbon steel SA 216-WCB 2 Carbon Steel SA 216-WCB (NACE) 3 St steel SA 351-CF8M (NACE) 4 St steel SA 351-CF8M O Special Accessories A Remote pressure sensing B Back flow preventer C Cooling/heating coils D Screwed cap E External filter **G Test gag *L Liquid duty P Packed lever T Field test connecr U Remote unloader S Special Pressure range Psig (Barg) Range Type 2 Type 4 Type ( ) ( ) ( ) 2 > (> ) These are min/max pressures of the pilot. Several springs are required cover these ranges Main valve trim 1 St St 316 and PEEK 2 St St 316 and Vin 4 St St 316 and Buna N 8 St St 316 and Polyurethane 9 St St 316 and PTFE O Special Main valve spring material 2 St steel 316 Z Inconel X750 (NACE) O Special *Dual phase duties should use the liquid trim versions of the modulating pilot Types 4 and 8 **Test gag available a max pressure of 1480 Psig 76

78 DIMENSIONS Size Orifice Rating A (ins) D (ins) B (ins) C (ins) C (ins) C (ins) Weight (ins) Type 2 Type Remote lbs (kg) 4 and 8 pilot 1 x 2 D, E, F 150x (19) 300x (20.5) 600x (20.5) 900x (24) 1500x (24) 2500x (24) 1.5 x 2 D, E, F 150x (21) 300x (22) 600x (22) 900x (26) 1500x (26) 2500x (26) 1.5 x 3 G, H 150x (25) 300x (28) 600x (28) 900x (36) 1500x (36) 2500x (36) 2 x 3 G, H, J 150x (25) 300x (27) 600x (29) 900x (42) 1500x (42) 1500x (42) 2500x (47) 2500x (47) SINGLE OUTLET Notes: Certified dimensions available on request. Dimensions A and B are for RF inlet, sensed integrally and remotely. Dimensions A and B are for RTJ inlet, sensed remotely. Add 1/2" dimensions A and B for RTJ inlets 1" 3" when sensed integrally. Add 3/4" dimensions A and B for RTJ inlets 4" 6" when sensed integrally. Add 1" dimensions A and B for RTJ inlet 8" when sensed integrally. Height may vary. Weight is approximate for Type 2 Pilot. For Types 4 and 8 Pilots add approx. 5kg. Cap withdrawal 40mm (1.6"). Additional filter 3.5kg. 77

79 Size Orifice Rating A (ins) D (ins) B (ins) C (ins) C (ins) C (ins) Weight (ins) Type 2 Type Remote lbs (kg) 4 and 8 pilot 3 x 4 J, K, L 150x (62) 300x (62) 600x (70) 600x (83) 900x (93) 1500x (97) 1500x (103) 4 x 6 L, M, 150x (102) N, P 300x (102) 600x (102) 600x (168) 900x (177) 1500x (182) 1500x (207) 6 x 8 Q, R 150x (183) 300x (185) 600x (190) 600x (252) 8 x 10 S, T 150x (270) 300x (300) 600x (330) 600x (430) 8x10x10 X 150x (435) 300x (435) DUAL OUTLET 78

80 OPERATING PRESSURES Maximum Operating Pressures API 526 Size Orifice ANSI Maximum (ins) Flange Pressure (Psig) Inlet Outlet Inlet Outlet 1x2 D, E, F /2x2 D, E, F /2x3 G, H x3 G, H x3 J x4 J, K Maximum Operating Pressures API 526 Size Orifice ANSI Maximum (ins) Flange Pressure (Psig) Inlet Outlet Inlet Outlet 3x4 L x6 L, M, N x6 P x8 Q x8 R x10 T x10x10 X Notes: Outlet pressure limits for temperature above 100 F conform ANSI/ASME B Pressure ratings given are for carbon steel bodies at -20 F 100 F. Austenitic stainless steel and other materials suitable for the service may be used within the code limits for pressure and temperature. API Standard 526 specifies lower allowable pressures for service temperatures above and below the ranges given in these charts, for both carbon and stainless steel bodies. 79

81 FLANGE PRESSURE / TEMPERATURE LIMITS Graph 1.0 ANSI Class 150,300,600 Inlet Flange Valves Set Pressure (Barg) Graph 2.0 ANSI Class 900,1500,2500 Inlet Flange Valves Set Pressure (Barg) Valves can be operated down -196 C (-320 F) when fitted with appropriate heating coils. 80

82 VALVE SIZING Overview A safety valve is fitted restrict system overpressure a predetermined level; this is normally 110% of the safety valve set pressure. In order ensure that the overpressure is not exceeded, the flow rate through the safety valve has be calculated. This calculation uses formulae which are derived from ASME VIII and API 520 Codes which are recognised throughout the world. Sizing The sizing of the safety valve uses data from the physical properties of the fluid, the valve set pressure, overpressure limits and effective discharge area. Formulae are presented for sizing valves on steam, gas and liquid. The constants used in the sizing formulae may have a different value dependent upon the valve type; where this is the case, it is clearly illustrated on the graph or table. All discharge coefficients are relative the valve type and have been approved the ASME VIII Code. Capacity tables are also shown for sizing on dry saturated steam, air and water. When calculating the flow rate through the safety valve, it is important that the flow rate through the valve is greater than the required flow rate generated by the system. Selection The safety valve selected must be suitable for the pressure and temperature required in the system; the appropriate section of the safety valve catalogue should be referred. The selected tal discharge area of the safety valve must always be greater than the calculated discharge area required relieve the system flow rate under all working conditions. VALVE SIZING FORMULAE Gas and Vapour Flow (1) Mass Flow (imperial units) A = W TZ C P Kd Fb Ff Fp M Kc (2) Volumetric Flow (imperial units) A = Q GTZ C P Kd Ff Fb Fp Kc (3) Constant (C) (imperial units) Table 1 C = 520 k 2 k+1 k+1 k-1 Nozzle Gas Constant K C C K C C Imperial Metric Imperial Metric

83 (4) Constant, Fb Fb = 2k k-1 Pb P k 2/k (k+1)/k - Pb P (k+1)/(k-1) 2 k+1 Liquid viscosity correction (Fv): When a relief valve is sized for viscous liquid service, it should first be sized as it was for nonviscous type application so that a preliminary required discharge area, A, can be obtained. The next larger orifice size should be used in determining the Reynold s number, R, from either of the following relationships: Steam Flow (Sonic and Subsonic flow) (5) Mass Flow (imperial units) or R = VL(2800G) e A (8) A = W 51.5 P Kd Fsh Fb Ff Fn Fp Kc R = 12,700VL u A (9) Viscosity Correction Facr Fv High pressure steam correction facr Fn:- Fn = 1.0 when P 1515 Psia Use the following formulae when P>1515 Psia (104.5 Bara) and P<3215 Psia (221.7 Bara) (6) Fn (imperial units) P Fn = P Liquid Flow (7) Liquid Flow (imperial units) A = VL G 38 Kd F1 Fv Kc (Pg - Pbg) Graph 1.0 Facr FV - capacity correction due viscosity. where: VL = flow rate at the flowing temperature, in U.S. gallons per minute. G = specific gravity of the liquid at the flowing temperature referred water (1.00 at 70ºF). e = absolute viscosity at the flowing temperature, in centipoise. A = effective discharge area, in square inches (from manufacturer s standard orifice areas). U = viscosity at the flowing temperature, in Saybolt Universal seconds. Note: Equation 9 is not recommended for viscosities less than 100 Saybolt Universal seconds. Hence use Fv = 1 After the value of R is determined, the facr Fv is obtained from graph 1.0. Fv is applied correct the preliminary required discharge area. If the corrected area exceeds the chosen standard orifice area, the above calculations should be repeated using the next larger standard orifice size. R = Reynold s Number 82

84 NOMENCLATURE Symbol Description Imperial Units A Orifice discharge area sq. ins C Gas constant, from the specific heat ratio (k); if unknown use 315 (see page 81 equation (3) or Table 1)...dimensionless... e Liquid absolute viscosity...centipoise... Ff Back pressure correction facr for gas - takes account of subsonic flow Balanced Bellows Valves (Page 87, Graph 2.0) Fb Back pressure correction facr for gas - takes account of subsonic flow Conventional Spring Loaded; WB 400; B Series; Pilot Operated Valves; Type 2, 4 and 8 Pilots: (use Graph 3.0, page 87 or equation (4) page 82)...dimensionless... Fl Back pressure correction facr for balanced bellows spring loaded valves (WB 100) liquid duty only, (use Graph 4.0, page 88)...dimensionless... Fn High temperature steam correction facr. Fp Subsonic flow facr for low set pressure on gas duty only, (use Graph 5.0, page 88)...dimensionless... Fsh Correction facr for superheated steam (Table 4, page 89)...dimensionless... Fv Liquid viscosity correction facr (Page 82, Graph 1.0)...dimensionless... G Specific gravity...dimensionless... Kc Derating facr = 0.9 for use with bursting discs; if no bursting disc use dimensionless... Kd Certified ASME Code Section VIII discharge coefficient: WB100 / 200 = (actual) (actuals are used on WB 300 / 400 = (actual) WB valves, as the WB 300B = (actual) derating facr has B Series = (derated) been applied the C Series = (derated) the orifice area). 6D Series (gas/steam) = (derated) 6D Series (liquid) = (derated) 7D Series (gas/steam) = (derated) 7D Series (liquid) = (derated) Pilots: Types 2, 4, 8 = gases (derated) Pilots: Types 4, 8 = liquids (derated) For full bore 8" x 10" x 10" pilot valves refer page 96...dimensionless... k Isentropic exponent (ratio of specific heats)...dimensionless... M Molecular weight...kg/kmole... P Set pressure + overpressure + atmospheric pressure where:- Overpressure = 10% or 3 Psi whichever is the greater Psia Atmospheric pressure = 14.7 Psia Pg Set pressure + Overpressure Psig Pb Back pressure at safety valve outlet Psia Pbg Back pressure at safety valve outlet Psig Q Volumetric flow 14.7 Psia and 60 ºF SCFM R Reynolds number...dimensionless... T Temperature at valve inlet deg.r = ºF deg.rankine VL Liquid flow rate us gpm W Mass flow rate lb/h w Liquid density lb/cu ft Z Compressibility facr (if unknown use 1.0)...dimensionless... 83

85 BACKPRESSURE AND BLOWDOWN LIMITS Figures shown are expressed as a percentage of set pressure. Valve type Built up Superimposed Constant Blowdown back variable back superimposed % pressure % pressure % back pressure % Safeset Pilot operated safety valves Refer page 69 Conventional spring loaded safety valves WB WB B C D Balanced bellows spring loaded safety valves WB WB WB 300B D (pisn) Gas D (pisn) Liq ORIFICE AREAS Orifice WB Series Safeset Pilot letter in 2 mm 2 in 2 mm 2 D E F G H J K L M N P Q R S T X WB Series Spring Loaded SRV WB100 / 200/ 300 / 300B & 400 The actual orifice area is 11% larger than those shown in this table. This ensures that after derating the discharge coefficient in accordance with industry standards, the full benefits of the API 526 orifice area can still be obtained. It is important use the actual coefficient of discharge as the areas are already derated. Safeset Pilot Operated SRV The areas shown in the table are actual orifice areas of the main valves and are larger than the standard API 526 dimensions. This ensures that after derating the discharge coefficient in accordance with industry standards, the full benefits of the API 526 orifice area can still be obtained. It is important use the derated coefficient of discharge as the areas are actuals. Orifice no. Safeflo in 2 mm Safeflo Spring Loaded Types The orifice areas shown in the table are in accordance with industry standards. API 526 does not specify requirements for thermal relief valves. It is important use the derated coefficient of discharge as the areas are actuals. 84

86 Table 2 Representative data on some vapours and gases useful in sizing safety relief valves Gas or Vapour k C C M M G* G imperial metric Acetaldehyde Acetic Acid Acetylene Air Ammonia Argon Benzene Butadiene n-butane Iso-Butane i-butane Iso-Butylene Carbon Dioxide Carbon Disulphate Carbon Monoxide Chloride Cyclohexane Decane Dowthern A Dowthern E Ethane Ethene (Ethylene) Ethyl Alcohol Ethyl Benzine Ethyl Chloride Freon Freon Freon Freon Helium n-heptane n-hexane Hydrogen Chloride Hydrogen Hydrogen Sulphide Methane Menthyl Alcochol Menthyl Butane Methyl Chloride Natural Gas Nitric Oxide Nitrogen Nitrous Oxide Nonane n-octane Oxygen n-pentane Phenol Propane Propylene Sulphur Dioxide Steam Styrene Toluene *Air = 1.0 at 14.7 Psia and 60ºF. 85

87 Table 3 Representative data on liquids useful in sizing safety valves Liquid G** G Acetic Acid Acene Ammonia Benzene , 2 Butadiene , 3 Butadiene Iso-Butane n-butane j-butane Carbon Dioxide Carbon Disulphide Chlorine Dowtherm A at 212ºF Dowtherm E at 212ºF Ethane Ethyl Alcohol Ethyl Benene Fuel Oil, Bunker C (max.) Fuel Oil, No. 3 (60ºF) (max.) Fuel Oil, No. 5 (60ºF) (max.) Fuel Oil, No. 6 (60ºF) (min.) Petrol (Gasoline) Liquid G** G n-heptane n-hexane Hydrochloric Acid (40%) Kerosene Methane Methyl Alcohol (100%) Methyl Butane Naphtha Nitric Acid (91%) Nitrogen Iso-Octane n-octane Oils, Minerals and Lubricants Iso-Pentane n-pentane Phosphoric Acid Propane Polythene Styrene Sulphuric Acid (87%) Water **Water = 1.0 at 70ºF. 86

88 Graph 2.0 Facr Ff For application sizing and capacity determination of balanced bellows safety relief valves against variable and constant back pressure vapours and gases only. Graph 3.0 Use the curve evaluate back pressure correction facr Fb, for pilot valves and for conventional valves with constant back pressure use. 87

89 Graph 4.0 Facr Fl For application sizing and capacity determination of balanced bellows safety relief valves against variable or constant back pressure liquids only (10% overpressure). Graph 5.0 Facr Fp For low set pressure vapours and gases only. 88

90 Table 4 Superheated Steam Correction Facrs FSH For capacity on superheated steam, multiply saturated steam capacity by correction facr below Set Pressure Saturated Total Steam Temperature in Degrees Fahrenheit p.s.i. steam gauge Temp. F

91 Pressure Protection 90

92 WATER CAPACITY CHART WB 100/200 Water Capacity U.S.G.P.M. 10% over pressure or 3 Psig minimum ORIFICE SIZE LETTER DESIGNATION Set Psig Gauge D E F G H J K L M N P Q R T Note: This chart should be used as a guideline only. 91

93 SATURATED STEAM CAPACITY CHART WB 400 Saturated Steam Capacities lb/hr 10% over pressure or 3 Psig minimum ORIFICE SIZE LETTER DESIGNATION Set Psig Gauge D E F G H J K L M N P Q R T Note: This chart should be used as a guideline only. 92

94 AIR CAPACITY CHART WB 400 Air Capacity s.c.f.m. 10% over pressure or 3 Psig minimum ORIFICE SIZE LETTER DESIGNATION Set Psig Gauge D E F G H J K L M N P Q R T Note: This chart should be used as a guideline only. 93

95 AIR CAPACITY CHART Pilot:Types 2, 4 & 8 Main Valve Discharge Capacities s.c.f.m. 10% over pressure or 3 Psig whichever is the greater. Kd = * ORIFICE SIZE LETTER DESIGNATION (DISCHARGE AREA sq in) Set Psig D E F G H J K L M N P Q R S T Gauge (0.164) (0.256) (0.338) (0.616) (0.871) (1.429) (2.139) (3.166) (4.307) (5.162) (7.068) (12.864) (17.758) (22.118) (28.862) *Note: Type 4 Pilot is available 1480 Psig. Type 8 Pilot is available from 1480 Psig. For 8" x 10" x 10" full bore capacity chart see page

96 WATER CAPACITY CHART - U.S.G.P.M. Pilot:Types 4 and 8 Main Valve Discharge Capacities Water u.s.g.p.m. 10% over pressure or 3 Psig whichever is the greater. Kd = * ORIFICE SIZE LETTER DESIGNATION (DISCHARGE AREA sq in) Set Psig D E F G H J K L M N P Q R S T Gauge (0.164) (0.256) (0.338) (0.616) (0.871) (1.429) (2.139) (3.166) (4.307) (5.162) (7.068) (12.864) (17.758) (22.118) (28.862) *Note: Type 4 Pilot is available 1480 Psig. Type 8 Pilot is available from 1480 Psig. For 8" x 10" x 10" full bore capacity chart see page

97 DUAL OUTLET / FULL BORE PILOT VALVE This valve is suitable for extremely high capacity duties. It achieves maximum discharge capacities by having a full bore 8 inch inlet with an available discharge area of sq.in. and two opposing 10 inch outlets, which can assist with reaction force problems. Available with Pilot Types 2 and 4. Capacity chart (full bore 8" x 10" x 10" pilot valve) Actual orifice area Air S.C.F.M. Water U.S.G.P.M. 60ºF and 10% over 10% over pressure Set pressure Pilot types 2 and 4 Pilot type 4 Psig Derated kd Derated kd *Note: Pilot type 2 is available from 29 Psig. Overpressure at 29 Psig is 3 Psig minimum. 96

98 REACTION FORCE - VAPOUR AND GASES The discharge from a safety relief valve exerts a reaction force on the valve or outlet piping. If the discharge piping is unsupported, this force is transmitted the valve inlet and associated piping. The following formula can be used determine the reaction force, assuming that critical flow of the gas or vapour occurs at the valve outlet. Discharge piping should be adequately supported. If pipework is not supported, it must be remembered that the reaction force will act on the end of the discharge pipe, and that the discharge pipe will act as a lever. The force applied the valve will therefore be determined by the reaction force and the geometry of the discharge pipework. F = W kt (k+1) M 366 +(Po x Ao) F = Reaction force (lbs). W = Flow rate of gas or vapour (lb/hr). K = Ratio of specific heat (imperial). M = Molecular weight of gas or vapour. T = Temperature at valve inlet, degrees Rankine (equal degrees F plus 460). Po = Outlet pressure (Psig). Ao = Discharge connection area (in 2 ). 97

99 DEFINITION OF TERMS Pressure Relief Devices A pressure relief device is actuated by inlet static pressure and designed open during an emergency or abnormal conditions prevent a rise of internal fluid pressure in excess of a specified value. The device also may be designed prevent excessive internal vacuum. The device may be a pressure relief valve, a nonreclosing pressure relief device, or a vacuum relief valve. A spring-loaded pressure relief valve is a pressure relief device designed aumatically reclose and prevent the further flow of fluid. A relief valve is a spring-loaded pressure relief valve, actuated by the static pressure upstream of the valve. The valve opens normally in proportion the pressure increase over the opening pressure. A relief valve is used primarily with incompressible fluids. A safety valve is a spring-loaded pressure relief valve, actuated by the static pressure upstream of the valve and characterised by rapid opening or pop action. A safety valve is normally used with compressible fluids. A safety relief valve is a spring-loaded pressure relief valve that may be used as either a safety or relief valve, depending on the application. A conventional pressure relief valve is a springloaded pressure relief valve whose performance characteristics are directly affected by changes in the back pressure on the valve. A balanced pressure relief valve is a springloaded pressure relief valve that incorporates a means for minimising the effect of back pressure on the performance characteristics. Dimensional Characteristics of Pressure Relief Devices The actual discharge area is the measured minimum net area that determines the flow through a valve. The curtain area is the area of the cylindrical or conical discharge opening between the seating surfaces above the nozzle seat created by the lift of the disc. The required discharge area is a nominal or computed area of a pressure relief valve used in recognised flow formulae determine the size of the valve. It will be less than the actual discharge area. The nozzle area is the cross-sectional flow area of a nozzle at the minimum nozzle diameter. A huddling chamber is an annular pressure chamber in a pressure relief valve located beyond the seat for the purpose of generating a rapid opening. The inlet size is the nominal pipe size (NPS) of the valve at the inlet connection, unless otherwise designated. The outlet size is the nominal pipe size (NPS) of the valve at the discharge connection, unless otherwise designated. Lift is the actual travel of the disc away form the closed position when a valve is relieving. A pilot-operated pressure relief valve is a pressure relief valve in which the main valve is combined with and controlled by an auxiliary pressure relief valve. A rupture disc device is a nonreclosing differential pressure relief device, actuated by inlet static pressure and designed function by bursting the pressure-containing rupture disc. A rupture disc device includes a rupture disc and a rupture disc holder. 98

100 OPERATIONAL CHARACTERISTICS The maximum operating pressure is the maximum pressure expected during system operation. The maximum allowable working pressure (MAWP) is the maximum gauge pressure permissible in a vessel at its designated temperature. The maximum allowable working pressure is the basis for the pressure setting of the pressure relief devices that protect the vessel. The design gauge pressure refers at least the most severe conditions of coincident temperature and pressure expected during operation. This pressure may be used in place of the maximum allowable working pressure in all cases where the MAWP has not been established. The design pressure is equal or less than the MAWP. Accumulation is the pressure increase over the maximum allowable working pressure of the vessel during discharge through the pressure relief device, expressed in pressure units or as a percentage. Maximum allowable accumulations are established by applicable codes for operating and fire contingencies. Overpressure is the pressure increase over the set pressure of the relieving device, expressed in pressure units or as a percentage. It is the same as accumulation when the relieving device is set at the maximum allowable working pressure of the vessel. Rated relieving capacity is that portion of the measured relieving capacity permitted by the applicable code or regulation be used as a basis for the application of a pressure relief device. Stamped capacity is the rated relieving capacity that appears on the device nameplate. The stamped capacity is based on the set pressure or burst pressure, plus the allowable overpressure for compressible fluids and the differential pressure for incompressible fluids. The set pressure is the inlet gauge pressure at which the pressure relief valve is set open under service conditions. The cold differential test pressure is the pressure at which the pressure relief valve is adjusted open on the test stand. The cold differential test pressure includes corrections for the service conditions of back pressure or temperature or both. Back Pressure is the pressure that exists at the outlet of a pressure relief device as a result of the pressure in the discharge system. It is the sum of the superimposed and built-up back pressure. Built up back pressure is the increase in pressure in the discharge header that develops as a result of flow after the pressure relief device opens. Superimposed back pressure is the static pressure that exists at the outlet of a pressure relief device at the time the device is required operate. It is the result of pressure in the discharge system coming from other sources and may be constant or variable. Blowdown is the difference between the set pressure and the closing pressure of a pressure relief valve, expressed as a percent of the set pressure or in pressure units. Opening pressure is the value of increasing inlet static pressure at which there is a measurable lift of the disc or at which discharge of the fluid becomes continuous. Closing pressure is the value of decreasing inlet static pressure at which the valve disc re-establishes contact with the seat or at which lift becomes zero. Simmer is the audible or visible escape of compressible fluid between the seat and disc at an inlet static pressure above the set pressure and at no measurable capacity. Leak-test pressure is the specified inlet static pressure at which a seat leak test is performed (normally 90% of set pressure according AP1 527). The term relieving conditions is used indicate the inlet pressure and temperature on a pressure relief device at a specific overpressure. The relieving pressure is equal the valve set pressure (or rupture disc burst pressure) plus the overpressure. (The temperature of the flowing fluid at relieving conditions may be higher or lower than the operating temperature.) Popping pressure is the pressure at which the valve disc rapidly moves from a slightly open (simmer) position a practically full open position. Discharge capacity is the actual mass flow rate of discharge which can also be expressed in volumetric terms. Equivalent capacity is the mass volumetric flow rate of a fluid calculated from the capacity of the valve for a test fluid. The fluids commonly used for the test purposes are steam, air and water. 99

101 PRESSURE TERM RELATIONSHIP Pressure Vessel Requirements Vessel Pressure % Design Pressure Safety Valve Characteristic Maximum permited accumulated pressure 110 Maximum relieving pressure Accumulation Overpressure (Typical) Design pressure 100 Set pressure Blowdown (Typical) Reseat pressure Operating margin Maximum operating pressure 90 Notes: The system operating pressure must not exceed the reseat pressure of the safety valve. Blowdown control is designed conform ASME Code Section V111, however liquid applications may demand up 15% blowdown. Overpressure and blowdowns shown are typical for spring loaded SRVs and can be reduced when using Safeset Pilot Operated SRVs. Refer the appropriate catalogue section for details. 100

102 NOTES Birkett Pressure Protection 101

103 SAFETY RELIEF VALVES B/C Series D Series WB Series Safeset COMPLEMENTARY PRODUCT LINES Bursting Discs Pressure Vacuum Valves Flame Arresters 102

104 Safety Systems UK Ltd. Sharp Street,Worsley, Manchester, UK, M28 3NA. Tel +44 (0) Fax +44 (0) Web site BIPR0410 Registered Office: Vicria Road, Leeds, LS11 5UG, UK