1 Compact Performance Threaded Safety relief valves Series 437. Type 437 438 439. Series 459. Type 459 462. CATALOG. The Safety Valve Series 459 Frontview 462 H4 GG. 4c Packed lever H4. Series 459 Frontview 462 H2 GG SB. 4c Balanced bellows design Series 459. Cap H2 Series 459. Flanged version Frontview 462 H2 GG Series 459. 4c Plain lever H3. Frontview 462 H3 GG. 4c Threaded Safety relief valves Spring Loaded Contents Contents General Applications 5. Features and Benefits 5. Codes and Standards 5. Overview 6. Series 437 9 Series 459 33. Materials 10 Materials 34. How to Order How to Order Numbering System 12 Numbering System 40. Article Numbers 14 Article Numbers 42. Available Connections 15 Available Connections 43. Dimensions and Weights 16 Dimensions and Weights 44. Pressure Temperature Ratings 18 Pressure Temperature Ratings 46. Accessories and Options Accessories and Options Caps and Levers 20 Caps and Levers 48. Metal Seat 21 Balanced Bellows 50. Soft Seal 22 Metal Seat 51. Heating Jacket 24 Soft Seal 52.
2 Spare Parts 25 Heating Jacket 54. Approvals Series 437 27 Lift Indicator 55. Capacities Type 437 28 Spare Parts 56. Capacities Type 438 / 439 30 Approvals Series 459 58. Specification Sheet 32 Capacities Series 459 59. Specification Sheet 62. Series 437. Cap H2. Series 437 Series 437. Packed lifting device Flanged version H4. LWN 3. Threaded Safety relief valves Spring Loaded General Leser s Compact perfor- Leser s Compact perfor- mance valves are spring loaded mance valves are designed and Safety relief valves of specially com- manufactured to highest standards and pact design, developed in close coop- compliant with and approved accord- eration with plant engineers and ser- ing to ASME (Sec. VIII, Div. 1), the vice specialists to protect special Canadian CRN, the European PED. processes and installations against standard (CE), the German AD 2000- overpressure. Merkblatt A2 and those of many other Extensive testing at the Leser ASME- countries, covering requirements from certified test lab together with up to end-users, OEM s and engineering date manufacturing processes ensure companies worldwide.
3 The reliability of these state of the art products. Type 437 / 438 / 439. Type 459 / 462. 4 LWN Threaded Safety relief valves Spring Loaded Applications Features and Benefits Codes and Standards Applications Features and Benefits Codes and Standards Leser s Compact Performance valves Leser s Compact Performance valves Leser s Compact Performance valves represent the ultimate solution for criti- cover a large variety of types, materials comply with the following codes and cal applications such as and options to fit any application: standards: Scope of Design Air/gas compressors and pumps Four valve sizes from 1/2 through ASME Section VIII National Board Technical gases and CO2 plants 11/2 certified capacities (single trim for Chemical equipment and piping Four orifice sizes from *D through F steam, gas and liquid service): UV- Pressure vessels and piping systems Threaded or flanged connections stamp containing gas, air, liquid or steam ANSI or DIN, Inlet rating: class 150# ASME Section II - materials LPG/LNG terminals, carriers etc.
4 To 2500# ASME B and ASME Cryogenic systems and oxygen Standard metal sealing: Type 437 and API 527, NACE MR 0175. application Type 459 or CRN. Thermal relief Soft seal: Type 438, 439 and 462 EN ISO 4126-1. Optional stainless steel bellows for PED 97 / 23 / EC (CE-marking), back pressure compensation VdTUEV-SV 100, Packed or plain lifting lever or AD 2000-Merkblatt A2. gastight cap Others Heating jacket available for high vis- cosity fluids Compact design and High Perform- ance Single trim for steam, gas and liquid for less spare parts and easier main- tenance Broad set pressure range up to 11600 psig Self-draining body design, avoids residues and reduces corrosion One-piece spindle reduces friction Unobstructed seat bore for maxi- mum capacity compared to nominal size Heavy duty design Type 459M. Various materials: chrome steel, stain- less steel, Monel or Hastelloy . All parts machined from bar stock for complete valves from special materials within short time Variety of capacities and versions, multiple choice of connections to fit any application Ease of plant design, installation, operation and maintenance Replaceable nozzle and disc Hardened or optional stellited metal sealing for longer product life Soft seat for superior tightness Ringless design, no adjustments LWN 5.
5 Threaded Safety relief valves Spring Loaded General Overview Overview Series 437 Series 459. Type 437: Metal to metal seat Type 459: Metal to metal seat Type 438: Soft seal, o-ring Type 462: Soft seal, o-ring Type 439: Soft seal, vulcanized Common Features Common Features Very Compact design Compact design Medium capacity High capacity compared to nominal Two standard body materials: sizes: for most common valve size chrome steel, stainless steel 3/4 x 1 up to D-orifice capacity *. All parts machined from bar stock Four different orifice sizes available various material options available Wide range of set pressures Various connections Optional balanced bellows Three body materials: cast iron, car- bon steel, stainless steel Various connections The diagram gives a quick overview about the main features of Leser 's Compact Performance valves : capacity Tightness Series 437 Series 459. and tightness. Type 439 Vulcanized soft seal Type 438 O-ring disc Type 462 O-ring disc Type 437 Sealing plate Type 459 Sealing plate Type 437 Metal to metal Type 459 Metal to metal Capacity /.
6 Orifice Selection of Threaded Safety relief valves Flanged Series 437 459. Criteria SRV. Type 437 438 439 459 462 526. Set Pressure > 2700psig . > 6000psig . High Flow Capacity D Orifice . is required F Orifice . Thermal Expansion application . Soft Seats 1 1 . Metal Seats . Temperature > 536 F . Temperature < -50 F . Variable Back Pressure occurs . Threaded Connections are required . Flanged Connections are required . Note: 1 Disc with sealing plate ( PTFE) is available. 6 LWN Threaded Safety relief valves Spring Loaded General Overview Metal to metal seat Type 437 and 459 provide for the pro- tection of installations where the metal to metal seat with its wide temperature Set range and good chemical resistance is Pressure suitable. [psig]. Type 437 and 459 can be equipped with an optional sealing plate disc for low temperature soft seat applications. 459. inch2. 459. inch2. 437. Long Version inch2 459. inch2. 437. Standard 459. Version inch2. inch2 Capacity /. Orifice Metal to metal seat Type 437 Type 459.
7 Capacity Orifice *D Capacity Orifice *D through F. Set pressure up to 2610 psig Set pressure up to 11600 psig Schnitt 459 H2 male 4c Sealing metal to metal Sealing metal to metal Design very Compact Design Compact , optional bellows, heavy duty design 459M. LWN 7. Threaded Safety relief valves Spring Loaded General Overview Soft seal Type 438, 439 and 462 provide for the protection of installations where a soft seat for superior tightness is required like for hard to hold gases. Set Pressure [psig]. Type 439 allows maintained tightness close to the set pressure especially at lower set pressures due to the advan- ced design of the vulcanized soft seat. 462. inch2. 438. Long Version inch2. 462. inch2. 438. Standard 462. Version inch2. inch2 Capacity/. Orifice 439 inch2. Soft seal Type 438 Type 439 Type 462. Capacity Orifice *D Capacity Orifice *D Capacity Orifice *D. Schnitt 439 H2 3 4x1 male Set pressure up to 2610 psig Set pressure up to 232 psig 4c through F Schnitt 462 H2 male 4c Sealing soft seal, O-ring Sealing vulcanized soft seal Set pressure up to 5075 psig Design very Compact Design very Compact Sealing soft seal, O-ring Design Compact , optional bellows 8 LWN Threaded Safety relief valves Spring Loaded Series 437.
8 Series 437. Type 437 / 438 / 439. Type 437 / 438 / 439. Flanged Version LWN 9. Series Threaded Safety relief valves Spring Loaded 437 Materials Type 437. Materials Type 437 40. 18. Type 4373 Type 4374. Item Part Name Chrome Steel Stainless Steel 19. 1 Inlet body SA 479 316L SA 479 316L 16. 2 Outlet body SA 479 430 SA 479 316L. Hardened 12. 7 Disc 316L. stainless steel 54. 12 Spindle AISI 420 316L. 16 / 17 Spring plate AISI 430F 316L 2. 18 Adjusting screw AISI 430F 316L. with bushing PTFE PTFE 17. 19 Lock nut Steel 316L. 57. 40 Cap H2 Steel 316L. 54 Spring Stainless steel Stainless steel 61. 57 Pin Stainless steel Stainless steel 7. Hardened 61 Ball 316. stainless steel 1. Flanged Version 1 Inlet body SA 479 316L SA 479 316L. 2 Outlet body SA 479 430 SA 479 316L. Outlet adaptor 316L 316L Type 437. Outlet flange 316L 316L. 48 Inlet flange 316L 316L. 40. 18. 19. 16. 12. 54. 2. 17. 57. 61. 7. 1. 48. Type 437. Flanged version 10 LWN Threaded Safety relief valves Spring Loaded Materials Type 438 Type 439.
9 Materials Type 438 Type 439 40. Type 4383 Type 4384. Item Part Name Type 4393 Type 4394 18. Chrome Steel Stainless Steel 1 Inlet body SA 479 316L SA 479 316L 19. 2 Outlet body SA 479 430 SA 479 316L. 7 Disc with 16. 316L 316L. soft seal 1. 12 Spindle AISI 420 316L. 12. 16 / 172 Spring plate AISI 430F 316L. Adjusting screw AISI 430F 316L. 18 54. with bushing PTFE PTFE. 19 Lock nut Steel 316L. 2. 40 Cap H2 Steel 316L. 54 Spring Stainless steel Stainless steel 57 Pin Stainless steel Stainless steel 7. 61 Ball Hardened 316. stainless steel 1. Flanged Version 1 Inlet body SA 479 316L SA 479 316L Type 438. 2 Outlet body SA 479 430 SA 479 316L O-ring seal Outlet adaptor 316L 316L. Outlet flange 316L 316L. 48 Inlet flange 316L 316L. Notes: CR. 1 Neoprene Schnitt 438 H2 3 4x1 male NBR Nitrile 4c EPDM Ethylene / Propylene 40. FPM Fluorocarbon FFKM Kalrez (Type 438). ISOLAST (Type 439) 18. 2 Item 17 only Type 439. 16. 12. 54. 2. 2. 17. 7. 57. 1. 61. 48. 7. 1. Type 439 Type 438. Vulcanized soft seal Flanged version LWN 11.
10 Schnitt 438 H2 Flansch Series Threaded Safety relief valves Spring Loaded 437 How to Order Numbering System How to Order Numbering System 1 Article Number 2 Set Pressure 3 Connections Please state unit (in gauge)! Please refer to table Available 1 2 3 4 Connections on page 15. Please do not exceed pressure range 437 4 . 314 2 mentioned in the spring charts. Please state one option code for each, inlet and outlet. 1 Type 437 / 438 / 439. Type Types of sealing 437 438 439. Metal seat Metal-to-metal . Metal-to-metal stellited . Soft seat EPDM . NBR . CR . FFKM (Kalrez ) . FKM (Viton ) . Plastic seat SP Vespel-SP1 . PCTFE Kel-F . PTDE-FDA Teflon . 2 Material Code 3 Body Material Chrome Steel 4 Body Material Stainless Steel 3 Valve Code Identifies valve size, body material and orifice, refer to page 14. 4 Code for lifting device 2 Screwed cap H2. 4 Packed lever H4. 100 psig V62 V71. Article No. Set Pressure Connections 12 LWN Threaded Safety relief valves Spring Loaded How to Order Numbering System 4 Options 5 Documentation 6.