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What is a high pressure butterfly valve?
Apr 07, 2018

What is a high pressure butterfly valve?

The high-pressure butterfly valve is a component used to realize the on-off and flow control of the pipeline system. It has been applied in many fields such as petroleum, chemical industry, metallurgy, and hydropower. Corresponding to different requirements, the high pressure butterfly valve can be used for product introduction according to the structural form, sealing surface material, sealing form, working temperature and other methods.

       In the known butterfly valve technology, its sealed form mostly adopts a sealed structure, and due to the limitation of the structural characteristics, it is adapted to industries such as high temperature resistance, high pressure, corrosion resistance, and wear resistance. The existing one of the more advanced butterfly valves is a three-eccentric metal hard-seal butterfly valve. The valve body and the valve seat are connected components, and the valve seat sealing surface layer is surfacing with temperature-resistant and corrosion-resistant alloy materials. The multi-layer soft stack seal is fixed on the valve plate. Compared with the traditional butterfly valve, this type of butterfly valve has high temperature resistance, easy operation, no friction when opening and closing, and the seal is increased when the torque of the transmission mechanism is increased during closing. The sealing performance and the advantages of prolonged service life.

       However, the butterfly valve still has the following problems in use:

       First, because the multi-layer soft and hard stack seals are fixed on the valve plate, when the valve plate is always open, the media forms a frontal flush against its sealing surface, and after the soft sealing tape in the metal plate interlayer is washed, it directly affects the sealing performance.

       Second, subject to structural constraints The structure is not adapted to the following diameter DN200 valves, because the overall structure of the valve plate is too thick, large flow resistance.

       Third, due to the principle of triple eccentric structure, the seal 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 device. In the normal flow state, the higher the medium pressure, the tighter the seal extrusion. When the medium of the flow passage is reversed, the seal begins to leak when the positive pressure between the valve plate and the valve seat is smaller than the pressure of the medium as the pressure of the medium increases.

       The utility model is characterized in that: the valve seat sealing ring is composed of multiple layers of stainless steel sheets on both sides of a soft T-shaped sealing ring.

       The sealing surface of the valve plate and the valve seat is an inclined conical structure, and a temperature-resistant, corrosion-resistant alloy material is surfacing on the oblique conical surface of the valve plate; a spring fixed between the adjusting ring pressure plate and the adjusting bolt of the pressure plate are assembled together. This structure effectively compensates the tolerance band between the 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 two-way interchanged medium conveying process.

       The high-pressure butterfly valve adopts a soft T-shaped multi-layer stainless steel sheet to form a seal ring, which has the dual advantages of metal hard seal and soft seal, and has zero leakage sealing performance under low temperature and high temperature conditions. The test proves that the positive flow state of the pool (the direction of flow of the medium is the same as the direction of rotation of the disc), the pressure of the sealing surface is generated by the torque of the transmission device and the pressure of the medium on the valve plate. When the pressure of the medium increases, the tighter conical surface of the valve plate and the seat sealing surface are squeezed tighter, and the sealing effect is better.

       When in the reverse flow state, the seal between the valve plate and the valve seat is pressed against the valve seat by the torque of the drive device. With the increase of the reverse medium pressure, the unit positive pressure between the valve plate and the valve seat is smaller than the medium pressure, the deformation of the spring of the adjustment ring after being loaded can compensate the tight pressure of the valve plate and the valve seat sealing surface. Plays automatic compensation.

        Therefore, unlike the prior art, the present invention does not install a soft and hard multi-layer seal ring on the valve plate, but directly mounts on the valve body. It is an ideal two-way hard seal method to add an adjustment ring between the pressure plate and the valve seat. . It will replace gate valves, high temperature butterfly valves and ball valves.



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