ISO 21013-4:2012

ISO 21013-4:2012 specifies the requirements for the design, manufacture and testing of pilot operated pressure relief valves for cryogenic service, i.e. for operation with cryogenic fluids in addition to operation at temperatures from ambient to cryogenic. It is restricted to valves not exceeding a size of DN 300 designed to relieve single phase vapours, gases, or mixtures of gases and/or vapours.