This International Standard specifies the requirements for the design, manufacture and testing of valves for a rated temperature of −40 °C and below (cryogenic service), i.e. for operation with cryogenic fluids in addition to operation at temperatures from ambient to cryogenic. It applies to all types of cryogenic valves, including vacuum jacketed cryogenic valves up to size DN 150. This International Standard is not applicable to pressure relief valves covered by ISO 21013-1.