As a component used to realize the on-off and flow control of pipeline system, butterfly valve has been widely used in many fields such as petroleum, chemical industry, metallurgy, hydropower and so on.

There is an advanced butterfly valve: three eccentric metal hard seal butterfly valve. The valve body and the valve seat are connected components, the sealing surface of the valve seat is overlaid with temperature resistant and corrosion resistant alloy materials, and multi-layer soft and hard laminated sealing rings are fixed on the valve plate. Compared with the traditional butterfly valve, this butterfly valve has the advantages of high temperature resistance, light operation, no friction in opening and closing. Its sealing performance has been improved. Prolonging the service life. The sealing can be compensated by increasing the torque of the transmission mechanism when closing.

However, there are still some problems with this butterfly valve during use:

1. When the valve plate is normally open, the medium forms a positive scouring on its sealing surface, the soft sealing belt in the metal sheet interlayer will directly affect the sealing performance.

2. The structure of the valve plate is thick and the flow resistance is large. It is not suitable for valves with a diameter below DN200.

3. The sealing between the sealing surface of the valve plate and the valve seat is to press the valve plate against the valve seat by the torque of the transmission. In normal flow state, the higher the medium pressure, the tighter the seal; When the channel medium is countercurrent, with the increase of medium pressure, the unit positive pressure between the valve plate and the valve seat is less than the medium pressure, the seal begins to leak.

Dervos introduces a high-performance three eccentric two-way hard sealing butterfly valve with zero leakage, flexible opening and closing, long service life, high temperature and high pressure resistance, corrosion resistance, wear resistance and wide application range.

The valve seat sealing ring is composed of multi-layer stainless steel sheets on both sides of soft T-shaped sealing ring. The sealing surface of the valve plate and the valve seat is an inclined conical structure. The temperature resistant and corrosion resistant alloy materials are overlaid on the inclined conical surface of the valve. The T-shaped sealing ring is fixed on the adjusting pressing plate and assembled with the adjusting bolt on the pressing 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, solves the sealing problem of the valve in the process of two-way interchangeable medium transmission, has the dual advantages of metal hard seal and soft seal. It has the sealing performance of zero leakage under both low temperature and high temperature.