Three-eccentric and bidirectional metal sealing butterfly valve

Abstract

The invention relates to a three-eccentric and bidirectional metal sealing butterfly valve. A flow passage is arranged in a valve body, a valve seat is sealed and fixedly arranged on the inner wall of the flow passage, a valve rod is vertically arranged and penetrates through the flow passage, the upper end of the valve rod and the valve body are sealed and connected by a first rotary type sealing and connecting structure, the lower end of the valve rod and the valve body are sealed and connected by a second rotary type sealing and connecting structure, a valve plate is arranged in the flow passage and is fixedly arranged on the valve rod, a mounting step is arranged at the periphery of the valve plate, a sealing ring is arranged on the mounting step and is pressed and fixed by a sealing ring press ring, the sealing ring press ring is fixedly connected with the valve plate by a first screw, and the sealing ring is in fit with the valve seat, so as to control the opening or closing of the valve. The three-eccentric and bidirectional metal sealing butterfly valve is characterized in that virtual gaps are respectively arranged between the inside surface of the sealing ring and the mounting step surface as well as between the outside surface of the sealing ring and the pressing surface of the sealing ring press ring, and sealing ring sealing gaskets are arranged in the virtual gaps. The three-eccentric and bidirectional metal sealing butterfly valve has the advantages that the structure design is novel, the requirement of stricter working condition is well met, the whole cost is reduced, and the service life of the valve is prolonged.

Description

technical field [0001] The invention relates to a triple eccentric bidirectional metal sealing butterfly valve, which belongs to the technical field of valve processing and manufacturing. Background technique [0002] Triple eccentric butterfly valve is a commonly used valve equipment. At present, most of the domestically produced triple eccentric butterfly valves are realized by the multi-layer sealing ring structure of flexible graphite and metal sheet. Most manufacturers use it, but this kind of multi-layer sealing ring also has great disadvantages. It is difficult to use it at high temperature, especially when the temperature exceeds 450 degrees. In addition, flexible graphite is easily damaged under the impact of high-pressure medium. Therefore, the seal is invalid; moreover, the flexible graphite is dynamically sealed in a medium containing water vapor for a long time, and the service life is very short. Therefore, domestically produced triple eccentric butterfly valv...

AI Technical Summary

Problems solved by technology

[0002] Triple eccentric butterfly valve is a commonly used valve equipment. At present, most of the domestically produced triple eccentric butterfly valves are realized by the multi-layer sealing ring structure of flexible graphite and metal sheet. Most manufacturers use it, but this kind of multi-layer sealing ring also has great disadvantages. It is difficult to use it at high temperature, especially when the temperature exceeds 450 degrees. In addition, flexible graphite is easily damaged under the impact of high-pressure medium. Thus making the seal invalid; moreover, the flexible graphite is dynamically sealed in the medium containing water vapor for a long time, and the service life is very short

However, imported products are expensive, and there will be jamming and leakage at high temperatures, so many domestic users have strong expectations that they can buy domestically replaced imported products

[0004] In addition, in the existing technology, the sealing rings in the domestic and foreign triple eccentric butterfly valves are 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 disadvantage is that once the surfacing welding sealing surface is damaged, it is difficult to repair and the interchangeability is poor

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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