I. Standard Overview
(I) BS 6364
BS 6364 is a design standard for CRYOGENIC VALVES formulated by the British Standards Institution (BSI). It is widely used in Europe and many countries and regions around the world. This standard covers multiple aspects such as the definition, design, material selection, non-destructive testing, and test methods of CRYOGENIC VALVES. Its scope of application includes valves from DN15 to the maximum nominal size, which can be opened and closed within the temperature range from -50°C to -196°C.
(II) MSS SP-134
MSS SP-134 is a standard formulated by the Manufacturers Standardization Society of the Valve and Fittings Industry (MSS) in the United States. It mainly targets valves for cryogenic applications, including requirements for valve body/bonnet extensions. It covers the material, design, dimension, manufacturing, non-destructive testing, and pressure testing requirements for cryogenic gate valves, globe valves, butterfly valves, ball valves, and check valves made of stainless steel and other alloys.
II. Comparison of Design Requirements
(I) Bonnet Extension Design
Items | BS 6364 | MSS SP-134 |
Purpose of Extension | To protect the packing and stuffing box, prevent the loss of packing elasticity caused by low temperature, and facilitate the winding of cold insulation materials | To ensure that the packing temperature remains within the allowable range when the valve operates in a low-temperature environment |
Minimum Extension Length | For valves used for purposes other than cold boxes, the minimum length of the packing gland extension is 250 mm | No unified minimum length is clearly specified, but it is emphasized that it should be determined according to materials and operating temperatures |
Cold Box Valves | The minimum length of the packing gland extension has specific regulations according to the nominal size | There are similar requirements, but the specific values and size ranges are different |
(II) Operation Angle Requirements
Items | BS 6364 | MSS SP-134 |
Gas Transmission Valves | The valve stem should be operable on or above the ground | No specific angle requirements are clearly mentioned |
Liquid Transmission Valves (Non-Cold Box Use) | The valve stem should be operable at an angle of ≥45° to the ground on the ground | No specific angle requirements are clearly mentioned |
Cold Box Valves | The valve stem should be operable at an angle of ≥15° to the ground on the ground | No specific angle requirements are clearly mentioned |
(III) Pressure Relief Design
Items | BS 6364 | MSS SP-134 |
Pressure Relief Requirements | In case of pressure increase in the valve cavity due to thermal expansion or liquid evaporation, a device that can relieve pressure to the nominal working pressure should be installed | It emphasizes that abnormal pressure increase should be prevented when cryogenic valves are in the closed state, but no specific pressure relief method is clearly specified |
Specific Measures | It can be achieved by setting pressure relief holes, pressure relief channels, or other means (such as relief seats) | No specific measures are clearly specified, but manufacturers are required to consider relevant risks |
III. Material and Non-Destructive Testing Requirements
(I) Material Selection
Items | BS 6364 | MSS SP-134 |
Material Range | It includes austenitic steel, non-ferrous metal materials, etc., and provides detailed material selection guidelines | It mainly targets stainless steel and other alloy materials |
Low-Temperature Adaptability | It emphasizes the mechanical properties and welding properties of materials at low temperatures | It requires materials to have good toughness and resistance to brittleness in a low-temperature environment |
(II) Non-Destructive Testing
Items | BS 6364 | MSS SP-134 |
Testing Methods | It includes various non-destructive testing methods such as radiographic testing and ultrasonic testing | It also covers multiple non-destructive testing methods, but the specific requirements are different |
Testing Frequency | 100% testing is required for key components and welding parts | Sampling inspection may be allowed for some components, but the specific requirements need to be determined according to the valve type and operating environment |
IV. Scope of Application and Application Scenarios
(I) Scope of Application
Items | BS 6364 | MSS SP-134 |
Applicable Temperature Range | -50°C to -196°C | No specific temperature range is clearly specified, but it is applicable to extremely low-temperature environments |
Applicable Valve Types | It includes cryogenic gate valves, globe valves, ball valves, etc. | It mainly targets cryogenic ball valves, gate valves, butterfly valves, etc. |
(II) Application Scenarios
Items | BS 6364 | MSS SP-134 |
Common Application Fields | It is widely used in fields such as chemical engineering and liquefied natural gas (LNG) | It is mainly used in petroleum, natural gas, and low-temperature fluid transmission systems |
International Recognition | It is widely recognized in Europe and many countries and regions around the world | It has a relatively high influence in the North American and global petroleum and natural gas industries |
V. Summary and Recommendations
Both BS 6364 and MSS SP-134 are important standards in the field of CRYOGENIC BALL VALVE design, each with its own characteristics and advantages. BS 6364 provides more detailed and specific regulations in terms of bonnet extension design, operation angle requirements, and material selection, especially being more targeted in the design of valves for cold boxes. On the other hand, MSS SP-134 has stricter requirements in terms of non-destructive testing and low-temperature sealing performance and is suitable for various cryogenic application scenarios.
For the design of J-VALVES CRYOGENIC BALL VALVES, it is recommended to comprehensively consider specific application scenarios and operating environments when selecting standards. If the project involves valves for cold boxes or requires more detailed guidance on bonnet extension design, BS 6364 may be a more appropriate choice. If the project mainly focuses on low-temperature sealing performance and non-destructive testing requirements, MSS SP-134 has more advantages. In addition, it is also necessary to combine local regulatory requirements and industry practices to ensure that the valve design complies with relevant standards and safety regulations.
