Triple eccentric metal seal butterfly valve

Abstract

The invention relates to a three eccentric metal seal butterfly valve comprising a valve, a valve plate and a valve rod. The upper portion of the valve rod is sequentially provided with a bearing ring, a first metal bearing and a filler pressing cover. The filler pressing cover is fixed on the valve body tightly, and a bottom cover is fixed at the bottom of the valve body tightly. The three eccentric metal seal butterfly valve is characterized in that the valve rod and the valve plate are connected to or mounted in the valve body through key pins, a valve body seal ring is arranged in the valve body and is tightly pressed by a single-edge multi-hole ring and a valve body pressing ring and is arranged in the valve plate, and a metal hollow O-shaped ring is arranged under the valve body seal ring; the upper and lower portions of the valve rod are provided with a second metal bearing, and a push stopping gasket and a gasket are arranged between the second metal bearing and a limiting semi-ring; a limiting plate is tightly fixed at the bottom end of the valve rod through limiting screws. The basic structure of a three eccentric metal seal butterfly valve is changed, and the three eccentric metal seal butterfly valve is adoptable to high temperature, high pressure conditions; using requirements are met, entire cost is lowered, and the service life of the valve is prolonged.

Description

technical field [0001] The invention relates to a triple-eccentric metal-sealed butterfly valve, which is used for medium cutoff of large-diameter pipelines of coal and chemical industry and application occasions of power station boiler steam systems, and belongs to the technical field of automatic control of mechanical equipment. Background technique [0002] At present, especially in the application of large-diameter pipeline medium cutting in coal chemical industry and power station boiler steam system, users and design institutes generally adopt imported methods. ; On the other hand, because of the important position, the product performance requirements are high; the triple eccentric butterfly valves used in this occasion are basically imported products, and the domestic triple eccentric butterfly valves are basically multi-level structures, using flexible graphite and metal sheets This structure is adopted by most manufacturers because it is easy to seal, but this mult...

AI Technical Summary

Problems solved by technology

[0002] At present, especially in the application of large-diameter pipeline medium cutting in coal chemical industry and power station boiler steam system, users and design institutes generally adopt imported methods. ; On the other hand, because of the important position, the product performance requirements are high; the triple eccentric butterfly valves used in this occasion are basically imported products, and the domestic triple eccentric butterfly valves are basically multi-level structures, using flexible graphite and metal sheets This structure is adopted by most manufacturers because it is easy to seal, but this multi-layer sealing ring also has great disadvantages, it is difficult to adapt to high temperature, especially when the temperature exceeds 450 degrees; in addition, Under the impact of high-pressure medium, flexible graphite is easily damaged, which makes the seal invalid; moreover, flexible graphite is dynamically sealed in a medium containing water vapor for a long time, and its life is very short.

[0003] In the existing technology, the sealing ring of triple eccentric butterfly valve structure is basically placed on the valve plate, the valve seat and the valve body are integrated design, and the valve body is surfacing with hard alloy. The biggest disadvantage of this design is that once the sealing surface is surfacing Damaged, difficult to repair, poor interchangeability

Facing the application in high temperature occasions, most foreign manufacturers meet the thermal expansion requirements by selecting the connection structure of the upper key and the lower pin, as well as appropriate material ratio and treatment, but there is no experience in this area in China, so the domestic triple eccentric butterfly valve is very difficult. It is difficult to meet the requirements of high temperature use, and it is easy to cause the valve to be stuck at high temperature

For the adjustment of high pressure difference, due to the large dynamic torque phenomenon, usually rely on increasing the size of the actuator to meet the adjustment requirements under high pressure difference, which will increase the overall cost of the valve

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