The butterfly plate of the flange expansionis installed in the diameter direction of the pipeline. In the cylindrical channel of the telescopic butterfly valve body, the disc-shaped butterfly plate rotates around the axis with the rotation angle between 0 ° and 90 °. When the rotation angle reaches 90 °, the valve will be fully open. Applicable temperature ≤ 80 ℃, used in petroleum, chemical, food, medicine, light textile, paper making, electric power, water supply and drainage, gas pipeline, as the role of regulating flow and intercepting medium, with the function of compensating pipeline expansion and contraction.
Advantages and disadvantages of flange expansion butterfly valve:
The flange retractable butterfly valve (the structure length can be retracted within a certain range) not only brings convenience to the disassembly and assembly of the valve, but also relieves the pipeline stress and protects the valve. At the same time, it also concentrates the installation mode of the butterfly valve plus the expansion device, making the space more compact. In general, this kind of valve does not need special maintenance. It only needs to regularly observe whether the expansion part has leakage and pull off. The initial cost of flange expansion butterfly valve is lower than that of flange butterfly valve with expansion device, but considering the maintenance cost in the future, it is not worth it.
If the sealing part of the butterfly valve is damaged and the sealing ring cannot be replaced and the butterfly valve needs to be scrapped, it will be scrapped together with the expansion part, with a large loss. For example, when the sealing part of butterfly valve needs to be maintained, the compression expansion part alone can’t realize the valve’s on-line maintenance free of disassembly, while the installation mode of butterfly valve plus expansion device has great advantages. Only the expansion device needs to be removed, that is, there is manual maintenance space to realize the valve’s maintenance free of disassembly (the butterfly valve is heavy, the expansion device is light, and the labor intensity of the expansion device is low).