Center line double flange butterfly valve is a component used to realize on-off and flow control of piping system. It has been widely used in many fields such as petroleum, chemical industry, metallurgy, hydropower and so on. In the well-known butterfly valve technology, its sealing form mostly adopts a sealing structure, and the sealing material is rubber, polytetrafluoroethylene, etc. Center line double flange butterfly valve is not suitable for industries such as high temperature, high pressure, corrosion resistance and wear resistance due to the limitation of structural characteristics.

Center line double flange butterfly valve structure center line sealing butterfly valve is that the entire butterfly plate and the valve seat are concentric in a 360° circle, with two-way sealing performance, and the flow rate can be adjusted freely. Most Center line double flange butterfly valves are of an interference seal type, that is, a rubber bushing is inserted on the valve seat of the valve body.
The structural feature of Center line double flange butterfly valve is that the shaft center of the valve stem, the center of the butterfly plate, and the center of the body are in the same position. The structure is simple and the manufacturing is convenient. Common rubber-lined butterfly valves belong to this category. The disadvantage is that the butterfly plate and the valve seat are always in a state of squeezing and scratching, with a large resistance distance and rapid wear. In order to overcome squeezing, scratching, and to ensure sealing performance, the valve seat basically uses elastic materials such as rubber or polytetrafluoroethylene, but it is also limited by the temperature in the use of the sealing material. This is why people traditionally think that Center line double The reason why the flange butterfly valve is not resistant to high temperatures.