First, because the multi-layer soft and hard stack seal fixed to the valve plate, when the valve plate normally open state of the medium to its sealing surface to form a positive erosion, metal sheet sandwich in the soft seal band after erosion directly affect the sealing performance.

Second, by the structural conditions of the structure is not suited to do the following diameter DN200 valve, because the overall structure of the valve plate is too thick, flow resistance.

Third, due to the principle of three eccentric structure, the sealing surface of the valve plate and the seal between the valve seat is the torque of the transmission device to the valve plate to the valve seat. In the positive flow state, the higher the medium pressure, the tighter the seal. When the flow medium is countercurrent with the media pressure increases the valve plate and the valve seat between the positive pressure is less than the medium pressure, the seal began to leak.

High-performance three eccentric hard seal butterfly valve,

Wherein the valve seat sealing ring is composed of a plurality of stainless steel sheets on both sides of a flexible T-shaped seal ring.

The sealing surface of the valve plate and the valve seat is an oblique conical structure, and the temperature and corrosion resistant alloy material is deposited on the inclined surface of the valve plate. The spring is fixed on the spring between the spring plate and the adjustment bolt assembly. This structure effectively compensates the elastic deformation between the sleeve and the valve body and the elastic deformation of the valve stem under the medium pressure, which solves the sealing problem of the valve in the process of the two-way interchangeable medium transportation.

The use of soft T-shaped multi-layer stainless steel sheet on both sides of the composition of the seal, with metal hard seal and soft seal of the double advantages, both in low temperature and high temperature conditions, have zero leakage sealing performance. The pressure of the sealing surface is caused by the torque of the transmission and the effect of the medium pressure on the valve plate when the pool is in the positive flow state (the direction of flow of the medium is the same as the direction of rotation of the disc). When the positive medium pressure increases, the valve plate oblique cone surface and the valve seat sealing surface squeeze tight, the better the sealing effect.

When the countercurrent state, the valve plate and the seat between the seal by the drive device torque to the valve plate to the valve seat. With the increase of the reverse medium pressure, the positive pressure between the valve plate and the valve seat is less than the medium pressure, the adjustment ring of the spring after the load stored in the deformation of the valve plate and valve seat sealing surface pressure Play an automatic compensation role.

Therefore, the utility model does not install the soft and hard multi-layer sealing ring on the valve plate as in the prior art, but is directly installed on the valve body, and the additional adjustment ring is formed between the pressure plate and the valve seat. The ideal double- The It will replace the gate valve, and the ball valve.