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.

Defect 1) of electromagnetic flowmeter cannot be used to measure gas, steam and liquid containing a lot of gas. 2) It can not be used to measure liquid media with low conductivity, such as petroleum products or organic solvents. Now, electromagnetic flowmeter is still powerless.