Research and Analysis of Cryogenic Valve Design Technology

Low temperature ball valve supplier to share with you: low temperature valve refers to the valve can be used in low temperature conditions, usually the working temperature of the valve below -40 ℃ is called a low temperature valve. Cryogenic valve is one of the indispensable important equipment in petrochemical industry, air separation, natural gas and other industries. Its quality determines whether it can be produced safely, economically and sustainably. With the development of modern technology, the use of cryogenic valves is becoming more and more extensive, and the demand is increasing.

From the perspective of materials, there are more than ten kinds of materials such as CF8, LCB, LF1, and F304, which can be applied to different temperatures and media, and all have formulated relevant standards, which not only stipulate the size and appearance quality requirements of castings and forgings, but also The chemical composition, heat treatment, mechanical properties, physical properties, welding repair, post-weld heat treatment, flaw detection, intergranular corrosion test (austenitic steel), impact test (low temperature valve) of forgings have strict technical requirements. The domestic standards are relatively simple, and the provisions for some specific issues are not detailed enough. In addition, domestic cryogenic valves still have a large gap with foreign products in terms of technical level, life, reliability, and supporting capabilities. Therefore, most of the cryogenic valves used in China currently rely on imports. In view of the deficiencies in the research and development of low temperature valves in China, I have carried out a more systematic research on low temperature gate valves, which are described below.

Low Temperature Gate Valves

1.General design requirements for low temperature valves

The working conditions of low temperature valves are harsh. Most of the working medium is flammable, explosive, and highly permeable. 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 low temperature valve, the following requirements are required for the design work:

(1) The valve and its assembly should have the ability to work for a long time under low temperature medium and ambient temperature (usually 10 years or 3500 ~ 5000 cycles);

(2) The valve should not be a significant heat source compared to the low temperature medium, because the inflow of heat will reduce the thermal efficiency, and the excessive inflow of heat may also cause the low temperature medium inside the valve to vaporize, resulting in abnormal pressure rise, causing danger;

(3) The low-temperature medium should not adversely affect the operating performance of the hand wheel and the sealing performance of the filler;

4) The structure of the valve assembly in direct contact with the low-temperature medium should meet the relevant explosion-proof and fire-proof requirements;

(5) The valve assembly working at low temperature cannot be lubricated, so measures need to be taken to prevent the friction parts from being scratched.

The above requirements should run through the cryogenic valve design process. In addition, it should be noted that the above requirements are specific to cryogenic valves. In the design process of cryogenic valves, the relevant general valve requirements should also be observed at the same time.