3、 Strong sealing characteristics The sealing characteristics of electric ball valves are also particularly strong. The electric ball valve is divided into two forms: elastic seal and metal seal. The so-called elastic sealing valve means that the sealing ring of the electric ball valve can be attached to the valve. In general, the service life of metal sealed valves is much longer than that of elastic sealed valves. The electric ball valve has excellent sealing property, which can well block the entry of air and maintain the absolute sealing property inside. It is also one of the major reasons why many enterprises choose it in industrial automation. 　　

However, the butterfly valve still has the following problems in use:
1、 Since multi-layer soft and hard laminated seal ring is fixed on the valve plate, when the valve plate is normally open, the medium will form a frontal erosion on its sealing surface. After the soft seal belt in the metal sandwich is washed, the sealing performance will be directly affected.
2、 Due to the limitation of structural conditions, this structure is not suitable for valves with a diameter below DN200, because the overall structure of the valve plate is too thick and the flow resistance is large.
3、 Due to the principle of three eccentric structure, the sealing between the sealing surface of the valve plate and the valve seat is made to press the valve plate against the valve seat by the torque of the transmission device. In the positive flow state, the higher the medium pressure, the tighter the sealing extrusion. When the medium in the flow channel is countercurrent, the unit positive pressure between the valve plate and the valve seat is less than the medium pressure with the increase of the medium pressure, and the seal begins to leak. The high-performance tri eccentric two-way hard sealing butterfly valve is characterized in that the seat sealing ring is composed of multi-layer stainless steel sheets on both sides of the soft T-shaped sealing ring. The sealing surface of the valve plate and the valve seat is of oblique cone structure, and the surface of the oblique cone of the valve plate is welded with heat-resistant and corrosion-resistant alloy materials; The spring fixed between the pressure plate of the adjusting ring is assembled with the adjusting bolt on the pressure plate. This structure effectively compensates the tolerance zone between the shaft sleeve and the valve body and the elastic deformation of the valve stem under the medium pressure, and solves the sealing problem of the valve in the process of two-way exchange of medium transportation. The sealing ring is composed of soft T-shaped multi-layer stainless steel sheets on both sides, which has the dual advantages of hard metal sealing and soft sealing. It has zero leakage sealing performance no matter at low temperature or high temperature.