Generally, urban natural gas pipelines are more than one hundred kilometers long. Although they are regularly patrolled and inspected, sometimes the pipelines need to pass through areas with complex conditions. The leakage of new pneumatic ball valves for natural gas gathering and transmission may cause serious fire accidents. Especially for pipelines near the city, it is particularly important to prevent the leakage of valves. Once the pipeline is put into operation, it is not allowed to stop operation within a few years, and it is not allowed to have a momentary interruption, let alone an overhaul period. Once the pipeline valves connected in series on the pipeline fail, the consequences are unimaginable. Therefore, the wearing parts of pipeline valves are required to have long service life and be safe and reliable.

4、 Selection method of pneumatic ball valve The working principle of pneumatic ball valve is to rotate the ball to make the pneumatic ball valve unblocked or blocked. The pneumatic ball valve is light to open and close, small in size, can be made into a large caliber, reliable in sealing, simple in structure, convenient in maintenance, and the sealing surface and spherical surface are often closed, not easy to be eroded by media, so it is widely used in various industries. Pneumatic ball valves can be roughly divided into 19 categories, including floating pneumatic ball valve, fixed pneumatic ball valve, metal hard seal pneumatic ball valve, V-type pneumatic ball valve, wafer type pneumatic ball valve, insulation pneumatic ball valve, pipeline pneumatic ball valve, rail pneumatic ball valve, top mounted pneumatic ball valve, pigging valve, high pressure forged pneumatic ball valve, three-way (four-way) pneumatic ball valve, internal thread pneumatic ball valve Integral pneumatic ball valve, cryogenic pneumatic ball valve, bellows pneumatic ball valve, eccentric semi pneumatic ball valve, all welded pneumatic ball valve, special pneumatic ball valve, etc. The O-type pneumatic ball valve is of floating structure. The ball core is precision casting, and the surface is plated with hard chrome. The valve seat is made of metal or reinforced polytetrafluoroethylene material. The flow port is the same as the pipe diameter, with great flow capacity, minimal flow resistance, and no leakage when closing. It is generally used as an on-off valve, especially suitable for high viscosity, fiber containing, and granular media. The V-type pneumatic ball valve adopts a fixed structure, and the ball core is provided with a V-shaped notch, which can realize proportional adjustment, and the flow characteristic is approximately equal.