Six-eccentric bidirectional sealing butterfly valve

Abstract

The invention discloses a six-eccentric bidirectional sealing butterfly valve. The six-eccentric bidirectional sealing butterfly valve comprises a valve body, a butterfly plate, a valve rod, a main valve seat, an auxiliary valve seat, a main sealing ring, a pressing ring and an auxiliary sealing ring. A six-eccentric structure is adopted, the combined action of double sealing pairs is adopted, reverse sealing is achieved to reach 1.1 times of nominal pressure, the valve rod and the butterfly plate do not need to be thickened, the model of an executing mechanism does not need to be increased, and the cost is greatly reduced. The fixed valve seats are adopted, movable valve seats are not adopted, the phenomenon of clamping stagnation of the movable valve seats does not exist, and the problem of unstable reverse sealing performance is fundamentally solved. The internal structure is not provided with a rubber O-shaped ring, and can resist high temperature of 425 DEG C or above. The main sealing pair and the auxiliary sealing pair adopt conical surface sealing, the sealing pairs do not interfere during opening and closing, and the opening and closing torque is small.

Description

technical field [0001] The invention belongs to the technical field of valves, in particular to a six-eccentric bidirectional sealing butterfly valve. Used in sewage, petroleum, chemical, pharmaceutical, electric power industries and other pipeline systems for cutting and adjustment, the medium is water, oil, steam, chemical medium, etc. It is widely used in pipelines under harsh working conditions such as high temperature, low temperature, high pressure, high wear resistance, high corrosion, and high vacuum that require bidirectional sealing. Background technique [0002] The defects of similar products in the market are as follows: [0003] Problem 1: A single fixed seat cannot achieve reverse sealing, especially the reverse leakage of specifications above DN400 is greater. If the reverse sealing pressure is not high, thickened valve stem and butterfly plate can be used to increase the size of the actuator To achieve, but the cost of the valve increases a lot, and the re...

AI Technical Summary

Problems solved by technology

[0003] Problem 1: A single fixed seat cannot achieve reverse sealing, especially the reverse leakage of specifications above DN400 is greater. If the reverse sealing pressure is not high, thickened valve stem and butterfly plate can be used to increase the size of the actuator To achieve, but the cost of the valve increases a lot, and the reverse seal can only reach 0.6 times the nominal pressure

[0004] Question 2: Conventional two-way sealing uses an independent movable valve seat. When reverse sealing is performed, the movable valve seat is pushed to move to the butterfly plate sealing ring, thereby realizing reverse sealing

When the medium is not clean, it is prone to stagnation, resulting in unstable reverse sealing performance

[0005] Question 3: Because the internal structure of the movable valve seat is equipped with a rubber O-ring, this material can only be used below 250 degrees

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