This bi-directional take multi-level triple eccentric metal hard seal structure, not only has ordinary multi-layer all excellent properties of triple eccentric metal hard
seal butterfly valve, due to the design reduces the radial eccentricity value reasonably, in closed valve stem torque is small, in static equilibrium, at the same time, the butterfly plate sealing ring with the high quality carbon materials with high toughness of multi-layer stainless steel structure, not only in the soft just can maintain the best closed with the valve seat, and have a very good self-compensation function, especially under the condition of the working condition of large temperature difference, can eliminate the resulting structure deformation influence on sealing performance, and because of adopted to stress during the process of processing andassembling method, makes the valve in the reverse pressure when the relative displacement be compensated fully, either forward or reverse pressure, therefore this butterfly valve are under full differential pressure to achieve zero leakage.