Specification for installation requirements of all welded pneumatic ball valves With the need to transport natural gas and oil, a large number of long-distance buried pipeline construction, all welded buried pneumatic ball valves are increasingly used, especially in large diameter long-distance oil and gas transmission pipeline devices. All buried pneumatic ball valves are buried underground, and the general design service life is 30 years. Because full welding is not convenient for disassembly and maintenance, the sealing, safety and long-life pipeline full welded direct buried pneumatic ball valves must be guaranteed. Before installation, a strict pressure test must be carried out.

The disadvantages are as follows:
1. Its regulating performance is worse than that of the stop valve, especially the pneumatic valve;
2. Because the main seat sealing ring material of pneumatic ball valve is polytetrafluoroethylene, it is inert to almost all chemicals. However, the physical characteristics of PTFE, including high expansion coefficient, sensitivity to cold flow and poor thermal conductivity, require that the design of valve seat seal must focus on these characteristics. When the sealing material becomes hard, the reliability of the seal will be damaged. Moreover, the temperature resistance grade of PTFE is low, and it can only be used at less than 180 ℃. Above this temperature, the sealing material will age. If long-term use is required, it is generally recommended to use it at 120 ℃; Advantages of pneumatic butterfly valve: 1. Convenient and quick opening and closing, labor saving, small fluid resistance, and frequent operation. 2. Simple structure, small size and light weight.
3. It is capable of transporting mud and storing little liquid at the pipe mouth.
4. Excellent sealing can be achieved under low pressure.
5. Good conditioning performance.