SD343H telescopic butterfly valve plate installed in the direction of pipe diameter. In butterfly valve cylindrical channel, disc-shaped butterfly plate around the axis of rotation, rotation angle of 0 ° ~90°, the 90 ° rotation, the valve is full-state license. This valve is generally horizontal mounting. Telescopic butterfly valve as a piping system used to implement off and flow control components, has been in the petroleum, chemical, metallurgy, electricity and many other fields are very widely used. The public to know in the butterfly valve technology, the use of its seal form sealed structure, sealing materials for rubber, polytetrafluoroethylene. As the structure of the restrictions, do not adapt to high temperature, high pressure and corrosion resistance, wear resistance and other industries. Present a more advanced butterfly valve three eccentric metal hard seal butterfly valve, a valve body and a valve seat for connecting component, the valve seat sealing surface layer welding temperature, corrosion resistant alloy material. Stacked multi-layer soft ring fixed in the valve plate, the valve and compared with the traditional butterfly valve has the advantages of high temperature resistance, convenient operation, open and close without friction, closed with the drive mechanism of the torque is increased to compensate for sealing, improves the valve sealing performance and prolong the service life of the advantages of.