Cryogenic Butterfly Valves are suitable for low-temperature media below -29℃ and are generally classified into three temperature ranges: -29℃ to -46℃ (or -50℃); -46℃ (or -50℃) to -101℃ (or -110℃); -101℃ (or -110℃) to -196℃. Applications below -196℃ are extremely rare and typically involve media such as liquid hydrogen or liquid helium. For service at -196℃ and above, the valves are designed and manufactured in accordance with BS 6364, ISO 28921-1, MSS SP-134, SPE 77-200, GB/T 24925, and other applicable standards. Pressure ratings include CL150, CL300, and CL600 (or PN16 to PN110). Bonnet extension height is designed according to the requirements of SPE 77-200, and customized designs can be provided if customers have special requirements for extension height.
Size:
NPS2~~NPS48 (DN50~~DN1200); sizes beyond this range can be customized according to customer requirements.
Material:
Body material is selected based on customer orders. For temperatures from -29℃ to -46℃ (or -50℃), LCB or LF2 is generally used. For temperatures below -46℃ (or -50℃), austenitic stainless steels such as CF8 (F304), CF3 (F304L), CF8M (F316), or CF3M (F316L) are typically used.
Internal Parts/Stem:
For temperatures from -29℃ to -46℃ (or -50℃), sealing rings can be made of soft sealing materials such as silicone rubber (VMQ), fluororubber (FKM), or PTFE. Below -46℃ (or -50℃), soft sealing rings are made of PCTFE. Multilayer sealing rings consist of stainless steel wire and flexible graphite composite rings, or hard-faced sealing surfaces made by surfacing, thermal spraying, or coating on both the seat and disc (with a corrosion-resistant base material). The stem is integrally forged or configured according to customer requirements.
Structure:
Valve body follows conventional valve designs. The extended bonnet is designed as per the standards specified in the product description, either as an integrally extended bonnet (without welding) or with an added pipe section in the middle of the bonnet, welded using full-penetration butt welding. Gas-shielded welding is not permitted (as it cannot ensure the impact resistance of the finished product). Welds must undergo non-destructive testing to verify their quality. Pressure relief holes or self-relieving seats can be added and marked according to customer requirements.
Operation Mode:
Manual, worm gear, electric, pneumatic, etc.
