Two-way pressure butterfly valve with circular sealing faces

The invention relates to a two-way pressure butterfly valve with circular sealing faces. The two-way pressure butterfly valve comprises a valve body, a movable valve seat, a butterfly plate and a valve stem. The valve body comprises a valve flow channel, the valve flow channel is provided with a valve flow channel center line which horizontally extends, the movable valve seat is mounted in the valve body, the butterfly plate is fixedly connected with the lower end of the valve stem, the movable valve seat is positioned on a side of the butterfly plate, a movable sealing ring is arranged on the butterfly plate and is fixed onto the butterfly plate by the aid of a butterfly plate compression ring, a sealing face of valve seat is arranged in the movable valve seat, a sealing face of the sealing ring is arranged on the circumference of the movable sealing ring, the sealing face of the sealing ring and the sealing face of the valve seat are matched with each other to form a sealing pair for sealing the valve, the sealing pair is circular sealing pair, the sealing face of the valve seat forms a part of an oblique elliptic cone which is deviated relative to the valve flow channel center line, the valve flow channel center line is positioned below the axial center line of the circular sealing pair, and a vertex is positioned below the valve flow channel center line. The two-way pressure butterfly valve has the advantages that the two-way pressure butterfly valve is simple in structure, long in service life, convenient to mount and good in centering and is abrasion-resistant, friction between the sealing faces can be prevented, excellent sealing effects can be realized, the area of the flow channel can be diminished, closing torque can be reduced, and the actuating mechanism type selection cost can be lowered.