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Hard seal butterfly valve is a kind of valve with circular disc (sealing piece) turning with the valve axis to open or close the pipeline. It is mainly used as a cut-off valve. It can also be designed to have the functions of cutting off and throttling adjustment. At present, hard seal butterfly valves are applied more and more in low-pressure large and medium-diameter pipelines. The disc of the hard seal butterfly valve is installed in the diameter direction of the pipeline. In the cylindrical passage of the butterfly valve body, the disc rotates around the axis, and the rotation angle is between 0 ~90. When the rotation angle is between 0 ~90, the valve is fully open.
Hard seal butterfly valve is simple in structure, small in volume and light in weight. It consists of only a few parts. The electric valve can be switched on and off quickly only by rotating 90 degrees. The operation is simple and the electric valve has good fluid control characteristics. When the butterfly valve is in full open position, the disc thickness is the only resistance when the medium flows through the valve body, so the pressure drop generated by the valve is very small, so it has better flow control characteristics. Butterfly valve has elastic seal and metal seal. Elastic sealing valve, sealing ring can be embedded in the valve body or attached to the butterfly plate.
If butterfly valve is required to be used as flow control, the main thing is to select the correct size and type of valve. The structure principle of hard seal butterfly valve is especially suitable for making large caliber valve. Hard seal butterfly valves are not only widely used in petroleum, gas, chemical industry, water treatment and other general industries, but also used in the cooling water system of thermal power plants.