DT373 worm gear clamped resilient hard seal butterfly valve adopts a “U” type stainless steel sealing ring, the precision elastic sealing ring and the polished butterfly plate three-dimensional eccentric contact. Solve the traditional eccentric butterfly valve in the opening and closing 0 ° ~ 10 ° instant sealing surface is still in sliding contact friction drawbacks, to realize the butterfly plate in the opening instant sealing surface that is separated, close the contact that is the effect of sealing to extend the life of the sealing performance of the best purpose. Therefore, it is widely used in metallurgy, electric power, petroleum, chemical industry, air, gas, combustible gases and water supply and drainage and other corrosive media pipeline, is the best device to regulate the flow and cut off the fluid.