ČSN EN ISO 28921-1

This part of ISO 28921 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.
This part of ISO 28921 covers isolation valves for use in cryogenic temperature service where the design low-temperature service is -50 °C down to -196 °C.
This part of ISO 28921 does not apply to valves for cryogenic services, designed in accordance with ISO 21011, used with cryogenic vessels.