The butterfly plate of the butterfly valve is installed in the diameter direction of the pipeline. In the cylindrical channel of the butterfly valve body, the disc-shaped butterfly plate rotates around the axis, and the rotation angle is between 0° and 90°. When the rotation reaches 90°, the valve is fully open.
The butterfly valve is simple in structure, small in size and light in weight, and consists of only a few parts. And it can be quickly opened and closed by only rotating 90°, and the valve has good fluid control characteristics. When the butterfly valve is in the open position, the thickness of the butterfly plate 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 good flow control characteristics. Butterfly valves have two sealing types: elastic seal and metal seal. For elastic sealing valves, the sealing ring can be embedded on the valve body or attached to the periphery of the butterfly plate.
Using metal seal valves generally lasts longer than elastic sealing valves, but it is difficult to achieve sealing. Metal seals can adapt to higher operating temperatures, while elastic seals have the disadvantage of being limited by temperature.
If the butterfly valve is required to be used as a flow control, the main thing is to correctly select the size and type of the valve. The structural principle of the butterfly valve is especially suitable for the production of large-diameter valves. Butterfly valves are not only widely used in general industries such as petroleum, gas, chemical industry, and water treatment, but also used in cooling water systems of thermal power plants.
Commonly used butterfly valves include wafer butterfly valves and flanged butterfly valves. Wafer type butterfly valve is to connect the valve between two pipe flanges with stud bolts, and flange type butterfly valve is to have flanges on the valve, and use bolts to connect the flanges at both ends of the valve to the pipe flanges.
