What are the advantages of low temperature stainless steel ball valves

Cryogenic stainless steel ball valves are mainly used in chemical plants, such as ethylene, liquefied natural gas, etc., to output liquid cryogenic media, such as ethylene, liquid oxygen, liquid hydrogen, etc. These types of media are not only flammable and explosive, but also gasify as the temperature rises, and the gasification volume is hundreds of times larger than the volume expansion. In addition, these media are highly permeable, easy to leak, and difficult to process and manufacture.
The advantages of low temperature stainless steel ball valves are as follows:
1. The material of the pressure-resistant part can withstand the expansion and contraction caused by the temperature change of the medium, and the structure of the sealing part will not be deformed when the temperature changes. When used in working conditions below -100°C, valve parts must be cold-treated after completion. That is, the parts must be cooled by immersion in a bath of liquid nitrogen. When the temperature of the part reaches -192°C, keep it for 1-2 hours and take it out. The outside of the box was naturally conditioned to room temperature with two reheat cycles.
2. The bonnet adopts a high-strength structure to protect the function of the stuffing box, keep the stuffing box away from low temperature, and ensure the sealing effect of the stuffing. At the same time, it can wrap the cold insulation material to prevent the loss of cold energy. Depending on the working temperature and the thickness of the insulation material, the neck length of the long neck can be selected into various lengths. When the sealing effect of the packing is reduced, grease can be added from the center of the stuffing box to form an oil seal layer, thereby reducing the pressure difference in the stuffing box and improving the sealing performance.
3. If the working temperature is lower than -100°C, the valve stem material should be chrome-plated or nitrided to increase the surface hardness of the valve stem and improve the reliability of the packing seal.
4. The low temperature stainless steel ball valve has a structure to prevent abnormal pressure rise. When the low temperature stainless steel ball valve medium evaporates, the volume expands rapidly and the pressure rises abnormally. When the pressure in the valve cavity rises, the valve cavity and the inlet are both connected, or a pressure relief valve is installed at the valve inlet to ensure the safe use of the valve.
5. The gasket of the low temperature stainless steel ball valve has reliable sealing and elasticity at room temperature, low temperature and temperature changes.