At present, the center line butterfly valve used to achieve piping system as an on-off and flow control components, has been used in many fields of petroleum, chemical, metallurgy, water and electricity are very widely used. In the butterfly valve has been publicly known technology, the seal forms a sealed structure, and sealing materials for rubber, PTFE and so. As the structure of the restrictions, not suited to high temperature, high pressure and corrosion resistance, wear and other industries. Present a more advanced three eccentric butterfly valve is a metal hard seal butterfly valve, valve and seat components for the piece, the valve seat sealing surface layer welding temperature, corrosion resistant alloy material. Stacked multi-layer soft sealing ring fixed in the valve plate, this butterfly valve compared with the conventional high temperature, easy operation, open and close without friction, closed with the transmission of the torque to compensate for increased seal, to improve a butterfly valve sealing performance and durability advantages.

The main items:

First, as hard and Concentric Resilient Seated Butterfly Valve fixed in the valve plate, when the valve plate normally open state media, the formation of its positive sealing surface erosion, sheet metal dissection of the soft seal by brushing with a direct impact on seal performance.

Two, by the structural constraints of the structure do not meet the following path DN200 valve, because the overall structure of valve plate is too thick, large flow resistance.

Three, because of the principle of the three eccentric structure, the sealing between the sealing surface and the valve seat plate is on the transmission of torque to the valve plate to the valve seat pressure. Positive flow state, the higher the pressure medium sealed tight squeeze. When the counter current flow when the medium with medium pressure valve plate and seat of the unit is less than the pressure medium pressure, the seal began to leak.

Structure editor

Structural characteristics of the stem axis, the center line butterfly valve butterfly plate center, body center in the same position. Has the advantages of simple structure, convenient manufacture. Rubber lined butterfly valve that is common in this category. Due to the shortcomings of the butterfly plate and the valve seat is always squeeze, scratch state, from the resistance, wear faster. To overcome the squeeze, scratch, to ensure the sealing performance, seat basically adopts elastic material such as rubber or PTFE, but also because of sealing materials are influenced by temperature limitations, which is why people think the traditional high-temperature butterfly valve is not of reasons.