Refrigerating systems and heat pumps - Valves - Requirements, testing and marking (ISO 21922:2021)

This document specifies safety requirements, certain functional requirements, and marking of valves and other components with similar bodies, hereinafter called valves, for use in refrigerating systems including heat pumps. This document includes requirements for valves with extension pipes. This document describes the procedure to be followed when designing valve parts subjected to pressure as well as the criteria to be used in the selection of materials. This document describes methods by which reduced impact values at low temperatures may be taken into account in a safe manner. This document applies to the design of bodies and bonnets for pressure relief devices, including bursting disc devices, with respect to pressure containment but it does not apply to any other aspects of the design or application of pressure relief devices. In addition, this document is applicable to valves with a maximum operating temperature not exceeding 200 °C and a maximum allowable pressure not exceeding 160 bar1).