Cryogenic ball valve

Product working principle and purpose:

Series low-temperature ball valve is mainly used in ethylene, liquefied natural gas and other chemical devices, the output of low-temperature liquid medium such as ethylene, liquid oxygen, liquid hydrogen. Such media is not only flammable and explosive, but also in the heating gasification, gasification volume expansion hundreds of times. And these media penetration, easy to leak, processing more difficult.
Product Structure Features:

1. Pressure parts of the material can withstand the temperature changes caused by the medium expansion, shrinkage, the structure of the sealing part of the temperature changes will not produce permanent deformation. For the following conditions -100 ℃, the valve parts should be cryogenic treatment before finishing, the parts will be immersed in a liquid nitrogen tank for cooling, when the temperature reaches -192 ℃ parts, start holding 1-2h, and then removed Natural treatment to the room temperature, review cycle 2 times.

2, the valve cover with long structure, its purpose to protect the function of stuffing box, the stuffing box at a farther position from the low temperature to ensure the sealing effect of packing, but also can be wound cold insulation material to prevent loss of cold energy. Long neck neck length according to the use of temperature and cold insulation material to choose a different length. When the packing sealing effect is reduced, you can add the grease from the middle of the packing box to form the oil seal layer, reducing the pressure difference of the packing box and improving the sealing performance.

3, the use of temperature below -100 ℃, the stem material after chrome or nitriding, improve the stem surface hardness and improve the reliability of packing seal.

4, the low temperature ball valve to prevent abnormal pressure structure, due to the low temperature valve gasification, the rapid expansion of its volume, the pressure will rise abnormally, when the valve cavity pressure rises, the valve cavity and import connectivity, or the valve inlet Pressure relief valve placed at the end to ensure the safe use of the valve.

5, low temperature ball valve gasket with at room temperature, low temperature conditions and temperature changes can be reliable sealing and recovery.
 

Product performance parameters:

 The main parts of the product material:

 
 Product main dimensions: