This standard specifies the terms and definitions, classification and marking, requirements, test methods, inspection rules, marking and packaging of metal bellows for valves (hereinafter referred to as bellows) and their components. This standard applies to bellows for stop valves, gate valves and their components. Bellows for other types of valves can also be used as a reference. This standard does not apply to non-metallic bellows and non-valve bellows.