Industrial cryogenic valve is a valve that works in low temperature medium. With the development of modern science and technology, the production scale of cryogenic engineering products continues to expand, and liquid oxygen, liquid nitrogen and liquefied petroleum gas are widely used. In particular, liquefied natural gas has been paid more and more attention by countries all over the world. The temperature of liquefied ammonia is -269 °C, the temperature of liquid hydrogen is -254 °C, the temperature of liquefied helium is -196 °C, the temperature of liquid oxygen is -183 °C, and the temperature of LNG is -162 °C. A large number of cryogenic valves are required. The use and demand of industrial cryogenic valve are increasing, and the requirements for technical performance and working characteristics are also increasing.
Temperature class of industrial cryogenic valve
Foreign countries are generally divided into six temperature grades according to the liquefaction temperature of various gases under normal pressure.
The first grade is 0~-46℃;
The second grade is -47~-60℃;
The third grade is -61~-70 ℃;
The fourth grade is -70~-101 ℃;
The fifth grade is -102~-196℃;
The sixth grade is below -253 ℃.
Generally, -46~-150 ℃ is called low temperature, and below -150 ℃ is called ultra-low temperature.
Material selection of industrial cryogenic valve
General design requirements for industrial cryogenic valve
The low temperature valve has harsh working conditions. Most of its working media are flammable, explosive and highly permeable substances. The minimum working temperature can reach -269 ℃, and the maximum working pressure can reach 10MPa. Therefore, the design, manufacture and inspection of cryogenic valves are very different from general valves. Generally, according to the working conditions of the cryogenic valve, the following requirements are put forward for the design work:
1) The valve and its components should have the ability to work for a long time under low temperature medium and ambient temperature (generally 10 years or 3500~5000 cycles);
2) The valve should not be a significant heat source relative to the low-temperature medium, because the inflow of heat will reduce the thermal efficiency, and if the heat inflow is too much, the low-temperature medium inside the valve may vaporize, resulting in abnormal pressure increase, causing danger;
3) The low temperature medium should not have a harmful effect on the operating performance of the handwheel and the sealing performance of the packing;
4) The structure of the valve assembly directly in contact with the low temperature medium shall meet the relevant explosion-proof and fire-proof requirements;
5) The valve assembly that works at low temperature cannot be lubricated, so it is necessary to take measures to prevent the friction parts from being scratched.
The above requirements should run through the design process of cryogenic valves. In addition, it should be noted that the above requirements are specific to cryogenic valves, and the requirements of related general valves should also be followed in the design process of cryogenic valves.
Industrial Cryogenic Valve Supplier - XINLIANTONG
Chengdu XinLianTong cryogenic equipment Co.,Ltd founded in 2006, We are the scientific and technological enterprise mainly engaged in the manufacture and development of industrial cryogenic valves, such as Cryogenic safety valve, Cryogenic globe valve, Cryogenic control valve etc. Our products are exported to various countries and are widely praised for their quality and good after-sales service. You are welcome to become our partner.
