This International Standard specifies design, type testing and marking requirements for: cylinder valves intended to be fitted to refillable transportable gas cylinders; main valves (excluding ball valves) for cylinder bundles; cylinder valves or main valves with integrated pressure regulator (VIPR); valves for pressure drums and tubes; which convey compressed, liquefied or dissolved gases. NOTE1 Where there is no risk of ambiguity, cylinder valves, main valves, VIPR and valves for pressure drums and tubes are addressed with the collective term “valves” within this document. This International Standard covers the function of a valve as a closure. This International Standard does not apply to valves for cryogenic equipment, portable fire extinguishers and liquefied petroleum gas (LPG), and quick-release cylinder valves (e.g. for fire-extinguishing, explosion protection and rescue applications), self-closing cylinder valves or ball valves. NOTE2 Requirements for valves for cryogenic vessels are specified in ISO21011 and at a regional level, e.g. in EN1626. Requirements for LPG valves are specified in ISO14245 or ISO15995. Requirements for quick-release cylinder valves are specified in ISO17871. Requirements for self-closing cylinder valves are specified. in ISO17879. Requirements for valves for portable fire extinguishers at a regional level are specified e.g. in EN3series. NOTE3 Requirements for manufacturing tests and examinations of valves covered by this International Standard are given in ISO14246. NOTE4 Additional requirements for VIPR are specified in ISO22435 for industrial applications or ISO10524‑3 for medical applications. Additional requirements for residual pressure valves with or without a non-return function are specified in ISO15996. Additional requirements for pressure-relief devices might be specified in international/regional regulations/standards. NOTE5 Additional specific requirements for valves for breathing apparatus at a regional level are specified e.g. in EN144 series. Additional specific requirements for quick-release valves for fixed fire-fighting systems are specified in ISO16003 and at a regional level e.g. in EN12094‑4.