Ball valves intended for cryogenic use differ from regular ball valves in a few essential ways. There is an extension stem in a cryogenic valve ensuring the stem seal temperature remains higher than that of the medium. The materials have been chosen to withstand extreme cold. Valves supplied are clean and dry.
Intermediate space pressure relief has been provided for ball valves intended for cryogenic use, since the cold liquid trapped in the intermediate space would otherwise expand upon gasification and break the valve. The pressure relief has been arranged by a drilled bore on the other side or spring-actuated self-relieving seals. The bore is a conventional and reliable solution that is also suitable for floating valves and functions without fail. The disadvantage of drilled pressure relief is that the valve is tight in one direction only. A more sophisticated solution is the use of self-relieving seals. In this case, trunnion ball valve seals are dimensioned so that if the pressure in the valve intermediate space exceeds that of the piping, the seal releases the pressure.
Our range of cryogenic ball valves is comprehensive. We represent FEMA, OMB, and PENTA. We offer soft seated and metal seated valves with both a floating and a trunnion structure. Top-entry and side-entry body structures are available. Valves are available with full port and reduced port.