This standard specifies the terms and definitions, design, manufacturing, inspection methods, inspection rules, factory requirements, packaging, transportation and storage of rigid vacuum insulated cryogenic tubes and their fittings (hereinafter referred to as cryogenic tubes). This standard applies to inner pipes with design pressures not greater than 4.0 MPa, design temperatures not lower than -196°C, nominal diameters of 25 mm to 100 mm, ambient temperatures of -40°C to 60°C, and transport media such as liquefied natural gas, liquid oxygen, Liquid nitrogen, liquid argon, etc., and adopts stainless steel rigid cryogenic tubes with a vacuum multi-layer insulation structure. Cryogenic pipes with an inner pipe design pressure greater than 4.0 MPa and a nominal diameter less than 25 mm or greater than 100 mm may also refer to this standard.