Anti-washing throttle valve sealing surface structure

Abstract

The invention discloses an anti-washing throttle valve sealing surface structure. The anti-washing throttle valve sealing surface structure comprises a valve clack, a valve cage and a valve seat, wherein the valve cage and the valve seat are of an integrated structure; a sealing surface of the valve seat is arranged on an inner wall of the valve cage; the upper surface of the valve clack is a valve clack sealing surface and a shroud band is arranged at the circumference of the valve clack sealing surface to prevent fluid from washing. The flowing area is controlled according to the distance between the valve clack and the valve cage or the depth of inserting the valve clack into the valve cage; the valve is completely closed by the tight contact of the valve clack sealing surface and the sealing surface of the valve seat; the two sealing surfaces are made of anti-wearing alloys. The valve cage is arranged on the structure outside the valve clack so that impurities are prevented from being clamped in the sealing surfaces; the anti-washing shroud band of the valve clack sealing surface is designed in order to prevent the valve clack sealing surface from being washed by the fluid; the valve clack sealing surface is arranged in the anti-washing shroud band; meanwhile, the valve clack sealing surface does not have a washing angle so that the problems of sealing surface washing and impurity carrying are effectively solved.

Description

technical field [0001] The invention relates to the technical field of high and low pressure bypass steam conversion valves in power plants, in particular to a sealing surface structure of an anti-scouring throttle valve. Background technique [0002] The high and low pressure bypass steam conversion valve (a throttle valve) in power plants has high working pressure and large pressure difference between front and back, and has high requirements for tightness. Imported valves are mostly used, and some domestic valves with foreign technology are used. Zhangjiakou Power Plant The high and low bypass pressure reducing valve of No. 5 unit is produced by Harbin Valve Co., Ltd. with German technology. It is found that the internal leakage is serious during use. It often occurs after one use after maintenance. Although there are many impurities in the steam-water system, However, the valve structure design is the main reason. In order to reduce the erosion of the steam flow on the s...

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Problems solved by technology

[0002] The high and low pressure bypass steam conversion valve (a throttle valve) in power plants has high working pressure and large pressure difference between front and back, and has high requirements for tightness. Imported valves are mostly used, and some domestic valves with foreign technology are used. Zhangjiakou Power Plant The high and low bypass pressure reducing valve of No. 5 unit is produced by Harbin Valve Co., Ltd. with German technology. It is found that the internal leakage is serious during use. It often occurs after one use after maintenance. Although there are many impurities in the steam-water system, However, the valve structure design is the main reason. In order to reduce the erosion of the steam flow on the sealing surface, it adopts the structure of placing the valve cage in the valve seat to adjust the flow rate. Although this can avoid the erosion of the sealing surface, the cleanliness of the steam There are very high requirements on the precision, and impurities such as welding slag larger than 2.5mm are not allowed, otherwise the impurities will be stuck in the sealing surface when the valve is closed, resulting in internal leakage

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