Pneumatic flange butterfly valve is composed of main parts such as valve body, valve plate, valve stem, elastic valve seat, pressure ring, etc. The side of the pressure ring is the sealing surface of the valve body and the sealing surface of the pipeline flange, forming a sealing pair. There are bolt holes in the side, which are used to tighten the pressure ring and fix the valve seat. At the same time, it is connected to the valve body as a whole, forming the total structural length of the valve. It is not only widely used in petroleum, gas, chemical industry, water treatment and other general industries, but also used in the water system of thermal power station.

The diameter of the sealing surface with screw holes on the side of the pressure ring of the movable flange butterfly valve is reduced. From the situation where users use flanges, most of them are flat welded flanges, with an inner diameter of 10-20mm larger than the nominal diameter. Reduce the use of sealing surfaces. If the valve and pipeline flange are different during installation, they will be misaligned and pressed onto the bolt hole diameter. At this point, the bolt hole diameter is exposed in the inner hole of the pipeline flange, causing leakage here. The leakage characteristic is that the medium flows out from the back of the pressure ring. Simply rotate 90 ° to quickly open and close, with simple operation. The electric valve has good fluid control charact