NF EN 12567

ISO 28921-1:2013 specifies requirements for design, dimensions, material, fabrication and production testing of isolation valves for low-temperature applications. It applies to gate, globe, check, butterfly and ball valves and can be used for other valve types used in low-temperature services. ISO 28921-1:2013 covers isolation valves for use in cryogenic temperature service where the design low-temperature service is ?50 °C down to ? 96 °C. It covers valves with body, bonnet, bonnet extension or cover made of metallic materials. ISO 28921-1:2013 covers valves of nominal sizes DN: 10; 15; 20; 25; 32; 40; 50; 65; 80; 100; 125; 150; 200; 250; 300; 350; 400; 450; 500; 600; 650; 700; 750; 800; 850; 900, corresponding to nominal pipe sizes NPS: 3/8; ½; ; 1; 11/4; 11/2; 2; 21/2; 3; 4; 5; 6; 8; 10; 12; 14; 16; 18; 20; 24; 26; 28; 30; 32; 34; 36. It applies to pressure designations: PN 16; 25; 40; 100; 160; 250; Class 150; 300; 600; 800; 900; 1 500.

ISO 28921-2:2015 specifies requirements for the type testing of isolating valves for low-temperature applications to verify the performance of valves at a low temperature from ? 50 °C down to ? 196 °C. NOTE Nominal sizes (DN), nominal pipe sizes (NPS), nominal pressure (PN) and Classes are covered in ISO 28921‑1. ISO 28921-2:2015 does not evaluate valve actuators unless they are integral part of the valve. Valves during testing can be operated manually or an actuator can be used during the testing. The effect of cold gas vapours during testing is taken into consideration in particular if the actuator is mounted directly over the test stand with the cold gases engulfing the actuator. ISO 28921-2:2015 does not apply to valves for cryogenic services, designed in accordance with ISO 21011, used with cryogenic vessels.