SWI cryogenic valves are designed for applications in extreme temperature and service conditions. Extended bonnet designs are of the enclosed vapour space type with an internally assembled one piece anti-blow-out stem design whereby all stem seals are located at the top of the bonnet away from the cold zone. The one-piece bonnet design provides for a pressurized column in which the cold liquid phase is changed, by heat transfer with the environment, to the gaseous phase forming a gas gap under the primary stem seals which protects the valve from malfunctioning due to freezing. This combined with excellent seat & seal designs and lower operational torques provides for exceptional performance at cryogenic conditions.
Design compliance and performance in accordance with BS6364, MSS SP-134 and ISO 28921 -1 are available per client requirement.