Bidirectional sealing butterfly valve

The utility model discloses a two-way sealing butterfly valve which comprises a valve body, a butterfly plate is arranged in the valve body, a valve seat is arranged on the side portion of the butterfly plate, a first inclined circumferential face is arranged on the inner circumferential face of the valve seat, a metal hard sealing ring capable of moving in the radial direction is installed on the butterfly plate, and a second inclined circumferential face is arranged on the outer contour of the metal hard sealing ring. An upper valve rod is eccentrically arranged at the top end of the butterfly plate, a worm and gear speed reducer is arranged above the valve body, a hand-cranking wheel is fixed on an input shaft of the worm and gear speed reducer, an output shaft of the worm and gear speed reducer and the upper valve rod are fixed together, a lower valve rod is rotationally connected to the valve body, and the lower valve rod and the bottom of the butterfly plate are eccentrically fixed together. The valve s