Engineering Reference
Valve Standards & Certifications
Detailed reference guides for the API, ASME, NACE, and ISO standards that govern industrial valve design, testing, material selection, and environmental compliance.
API 6D
Specification for Pipeline and Piping Valves
API 607
Fire Test for Quarter-Turn Valves and Valves Equipped with Nonmetallic Seats
ASME B16.34
Valves - Flanged, Threaded, and Welding End
API 598
Valve Inspection and Testing
NACE MR0175 / ISO 15156
Petroleum and Natural Gas Industries - Materials for Use in H₂S-Containing Environments (Sour Service)
API 609
Butterfly Valves: Double-Flanged, Lug- and Wafer-Type
ISO 15848
Measurement, Test, and Qualification Procedures for Fugitive Emissions - Industrial Valves
API 526
Flanged Steel Pressure-Relief Valves
Design & Dimensional Standards
Specification for Pipeline and Piping Valves
API 6D is the most widely cited standard for pipeline and piping valves in the oil and gas industry.
Read standard guide
Valves - Flanged, Threaded, and Welding End
ASME B16.
Read standard guide
Butterfly Valves: Double-Flanged, Lug- and Wafer-Type
API 609 is the dimensional and performance standard for butterfly valves in petroleum and natural gas service.
Read standard guide
Flanged Steel Pressure-Relief Valves
API 526 is the standard for flanged steel pressure relief valves (PRVs / PSVs) used in petroleum, petrochemical, and natural gas processing.
Read standard guide
Specification for Steel Gate Valves - Flanged and Butt-Welding Ends, Bolted and Pressure-Seal Bonnets
API 600 is the primary design and manufacturing standard for full-opening steel gate valves in sizes NPS 2 and larger with flanged or butt-weld ends and bolted or pressure-seal bonnets.
Read standard guide
Gate, Globe, and Check Valves for Sizes DN 100 and Smaller for the Petroleum and Natural Gas Industries
API 602 covers compact forged steel gate, globe, and check valves in sizes NPS 1½ and smaller for petroleum and natural gas service.
Read standard guide
Check Valves: Flanged, Lug, Wafer, and Butt-Welding
API 594 is the design and testing standard for flanged, lug, wafer, and butt-welding check valves including swing check, dual plate (double door), and tilting disc check valves.
Read standard guide
Buttwelding Ends
ASME B16.
Read standard guide
Industrial Valves - Metallic Butterfly Valves
EN 593 is the European standard governing the design, manufacture, materials, and testing of metallic butterfly valves for industrial service.
Read standard guide
Face-to-Face and End-to-End Dimensions of Valves
ASME B16.
Read standard guide
Pipe Flanges and Flanged Fittings NPS 1/2 through NPS 24 Metric/Inch Standard
ASME B16.
Read standard guide
Bronze Gate, Globe, Angle and Check Valves
MSS SP-80 covers the design, manufacture, and testing requirements for bronze gate, globe, angle, and swing check valves intended for general utility service at moderate temperatures and pressures.
Read standard guide
Steel Ball Valves for Petroleum, Petrochemical and Allied Industries
BS 5351 is the British Standard covering steel ball valves for the petroleum, petrochemical, and allied industries, serving a similar purpose to API 6D and API 608 but tailored for the UK and European market requirements.
Read standard guide
Specification for Wellhead and Christmas Tree Equipment
API 6A is the fundamental specification for wellhead and Christmas tree equipment used in oil and gas well drilling and production.
Read standard guide
Flanges and Their Joints - Circular Flanges for Pipes, Valves, Fittings and Accessories, PN Designated - Part 1: Steel Flanges
EN 1092-1 is the European standard for steel flanges, defining the PN-designated (Pressure Nominal) pressure ratings, dimensions, tolerances, materials, and marking requirements for circular flanges used on pipes, valves, fittings, and accessories.
Read standard guide
Petroleum and Natural Gas Industries - Pipeline Transportation Systems - Pipeline Valves
ISO 14313 is the international standard for pipeline valves used in petroleum and natural gas transportation systems, published as the ISO counterpart to API 6D.
Read standard guide
Steel Globe Valves - Flanged and Butt-Welding Ends, Bolted Bonnet
API 623 is the API specification for steel globe valves with flanged and butt-welding ends and bolted bonnets, intended for petroleum, petrochemical, and allied industries.
Read standard guide
Steel Globe and Globe Stop and Check Valves (Flanged and Butt-Welding Ends) for the Petroleum, Petrochemical and Allied Industries
BS 1873 is the British Standard for steel globe valves and globe stop-and-check valves with flanged and butt-welding ends, covering petroleum, petrochemical, and allied industries.
Read standard guide
Large Diameter Steel Flanges NPS 26 Through NPS 60 Metric/Inch Standard
ASME B16.
Read standard guide
Design and Operation of Subsea Production Systems - Subsea Wellhead and Tree Equipment
API 17D is the governing specification for subsea wellhead equipment and Christmas trees, covering the design, manufacture, testing, and operation of all pressure-containing and pressure-controlling components installed on the seabed at water depths up to 3,000 metres.
Read standard guide
Rubber-Seated Butterfly Valves, 3 In. Through 72 In. (76 mm through 1,800 mm)
AWWA C504 is the primary standard for rubber-seated (concentric and double-eccentric) butterfly valves in water main and waterworks service - covering drinking water transmission mains, pump stations, water treatment plants, and raw water intake systems.
Read standard guide
Industrial Valves - Shell Design Strength
EN 12516 specifies the method for calculating the minimum required wall thickness of valve pressure-containing shells (body and bonnet) and sets the basis for European valve design strength calculations - serving the same function as ASME B16.
Read standard guide
Quality Management Systems - Requirements
ISO 9001:2015 is the world's most recognised quality management system standard, used by over one million organisations in 170 countries.
Read standard guide
Hydrogen Piping and Pipelines
ASME B31.
Read standard guide
Specification for High-Test Wrought Butt-Welding Fittings
MSS SP-75 specifies requirements for wrought (seamless or welded) steel butt-welding fittings for high-pressure gas and oil pipelines - elbows, tees, reducers, caps, and similar components.
Read standard guide
Metal Plug Valves - Flanged, Threaded and Welding End
API 599 specifies requirements for metal plug valves with flanged, threaded, and welding end connections, in sizes NPS ½" to NPS 24" for Class 150 to 600.
Read standard guide
EN 558 - Face-to-Face and Centre-to-Face Dimensions of Metal Valves for Use in Flanged Pipe Systems
EN 558 is the European equivalent of ASME B16.
Read standard guide
ISO 17292 - Metal Ball Valves for Petroleum, Petrochemical and Allied Industries
ISO 17292 is the international equivalent of API 6D for ball valves, widely required on Asian and Middle East tenders alongside or instead of API 6D - especially for projects outside North America.
Read standard guide
BS 6364 - Specification for Valves for Cryogenic Service
BS 6364 is the primary cryogenic valve standard, specifying design and testing requirements for valves used in LNG, liquid nitrogen, liquid oxygen, and other cryogenic services below -46°C.
Read standard guide
Testing & Inspection Standards
Fire Test for Quarter-Turn Valves and Valves Equipped with Nonmetallic Seats
API 607 is the fire-test standard for quarter-turn valves (ball valves and butterfly valves) and other valves with soft (non-metallic) seats and seals.
Read standard guide
Valve Inspection and Testing
API 598 is the universal valve testing and inspection standard, defining acceptable leakage rates (leak classes) for hydrostatic shell tests, seat leakage tests, and backseat tests.
Read standard guide
Measurement, Test, and Qualification Procedures for Fugitive Emissions - Industrial Valves
ISO 15848 defines the test procedures and acceptance criteria for fugitive emissions (stem leakage) from industrial valves - primarily the leakage of volatile organic compounds (VOCs), methane, and other greenhouse gases around the stem packing.
Read standard guide
Testing of Valves - Production Pressure Testing and Fire Type Testing Requirements
BS 6755 is the British Standard for valve testing, covering production pressure testing (Part 1) and fire type testing (Part 2).
Read standard guide
Specification for Fire Testing of Valves
API 6FA specifies the fire test procedure and performance criteria for gate valves, ball valves, plug valves, check valves, and other valves used in petroleum and natural gas service where fire safety is required.
Read standard guide
Industrial Valves - Pressure Testing of Metallic Valves
ISO 5208 is the international standard for pressure testing of metallic valves.
Read standard guide
Testing of Valves - Fire Type-Testing Requirements
ISO 10497 specifies the fire type-testing requirements for industrial valves to assess their ability to limit leakage during and after exposure to fire.
Read standard guide
Seat Tightness of Pressure Relief Valves
API 527 defines the acceptable seat tightness (leakage limits) for pressure relief valves (PRVs) and safety relief valves at inlet pressure conditions below the set pressure.
Read standard guide
Qualification Testing of Quarter-Turn Valves for Fugitive Emissions
API 641 is the primary qualification testing standard for fugitive emissions from quarter-turn valves - primarily ball valves and butterfly valves.
Read standard guide
Industrial Valves - Measurement, Test and Qualification Procedures for Fugitive Emissions - Part 1
ISO 15848-1 specifies measurement, test, and qualification procedures for fugitive emissions from industrial valves.
Read standard guide
Industrial Valves - Testing of Metallic Valves (Parts 1 and 2)
EN 12266 is the European standard for pressure testing of metallic industrial valves - the EU equivalent of API 598 and ISO 5208, commonly specified in European refinery and petrochemical projects.
Read standard guide
API 622 - Type Testing of Process Valve Packing for Fugitive Emissions
API 622 specifies type testing requirements for compression packing used in gate, globe, and other rising-stem valves to qualify packing sets for fugitive emissions service - complementing API 641 for ball valve stem seals.
Read standard guide
API 624 - Type Testing of Rising and Setting Stem Valves Equipped with Graphite Packing for Fugitive Emissions
API 624 extends API 622 by specifying complete valve-level fugitive emissions type testing for gate and globe valves equipped with graphite packing - a valve-level certification complementing the packing-level API 622 test.
Read standard guide
Material Standards
Petroleum and Natural Gas Industries - Materials for Use in H₂S-Containing Environments (Sour Service)
NACE MR0175 (now jointly published as ISO 15156) is the governing standard for material selection in equipment exposed to wet hydrogen sulphide (H₂S) - commonly called 'sour service'.
Read standard guide
Quality Standard for Steel Castings and Forgings for Valves, Flanges, Fittings and Other Piping Components
MSS SP-55 is the visual quality standard used to evaluate steel castings for valves, flanges, and fittings.
Read standard guide
Materials Resistant to Sulfide Stress Cracking in Corrosive Petroleum Refinery Environments
NACE MR0103 specifies the metallurgical requirements for materials used in petroleum refinery environments where wet hydrogen sulfide (H₂S) can cause sulfide stress cracking (SSC).
Read standard guide
Material Data Sheets and Element Requirements for Piping
NORSOK M-630 is a Norwegian offshore standard that specifies material data sheets (MDS) and element requirements for piping components - including valves - used on the Norwegian Continental Shelf.
Read standard guide
Installation Standards
Process Piping
ASME B31.
Read standard guide
Power Piping
ASME B31.
Read standard guide
Pipeline Transportation Systems for Liquids and Slurries
ASME B31.
Read standard guide
Gas Transmission and Distribution Piping Systems
ASME B31.
Read standard guide
Certifications Vajra Valves Carry
All certification documentation is supplied as standard with every order. Third-party inspection at manufacturer's works is accepted and coordinated at no additional charge.
Need Valves to a Specific Standard?
Share your standard requirement - API 6D, NACE MR0175, ISO 15848, IBR - and we'll quote compliant valves with full certification in 24 hours.