Valve for medium with temperature of -40℃ to -196℃ is called cryogenic valve. Cryogenic ball valve is a kind of valve that is mainly for ethylene, liquefied natural gas and other chemical device. It’s mainly divided into cryogenic floating ball valve and cryogenic standing ball valve. Long-necked structure is not usually applied for temperature above -50℃, and applied for temperature below -50℃. It aims to protect the stuffing box. Locate stuffing box far away from low temperature. To guarantee sealing effect of the stuffing, cold insulation material also can be wound to prevent loss of cold energy. it’s a kind of valve that mainly for ethylene, liquefied natural gas and other chemical device.