The valve suitable for medium temperature -40℃~ -196℃ is called cryogenic valve. Mainly used in ethylene, liquefied natural gas plants, natural gas LPG LNG storage tanks, receiving bases and satellite stations, air separation equipment, petrochemical tail gas separation equipment, liquid oxygen, liquid nitrogen, liquid argon, carbon dioxide cryogenic storage tanks and tank trucks, pressure transformation On devices such as adsorbing oxygen. The output liquid cryogenic medium, such as ethylene, liquid oxygen, liquid hydrogen, liquefied natural gas, liquefied petroleum products, etc., is not only inflammable and explosive, but also vaporizes when the temperature rises, and the volume expands hundreds of times when it is vaporized.