Common knowledge about butterfly valves

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Basic knowledge of butterfly valves – Compiled by Global Valve Network, December 21, 2007. Source: [Large Medium Small] ‘Close’ – Go directly to the forum. -------------------------------------------------------------------------------- The butterfly disc of a butterfly valve is installed in the diameter direction of the pipeline. Within the cylindrical channel of the butterfly valve body, the disc-shaped butterfly plate rotates around its axis by an angle ranging from 0° to 90°; when it reaches 90°, the valve is in its fully open position. Butterfly valves have a simple structure, are small in size and light in weight, consisting of only a few components. Moreover, it can be quickly opened and closed by simply rotating 90°, making operation simple; at the same time, this valve boasts excellent fluid control properties. When the butterfly valve is in the fully open position, the thickness of the butterfly disc is the only resistance to the flow of the medium through the valve body; as a result, the pressure drop across this valve is very small, giving it excellent flow control characteristics. Butterfly valves come in two types of sealing: elastic sealing and metallic sealing. Elastic-sealing valves, where the sealing ring can be embedded in the valve body or attached around the butterfly disc. Valves with metal seals generally have a longer lifespan than those with elastic seals, but it is difficult to achieve complete sealing. Metal seals can withstand higher operating temperatures, while elastic seals have the drawback of being limited by temperature. If a butterfly valve is to be used for flow control, the key is to correctly select its size and type. The structural principle of butterfly valves makes them particularly suitable for manufacturing large-diameter valves. Butterfly valves are widely used not only in general industries such as petroleum, gas, chemicals, and water treatment, but also in the cooling water systems of thermal power plants. The commonly used butterfly valves are wafer-type butterfly valves and flanged butterfly valves. A wafer butterfly valve is connected between two pipe flanges using bolts, while a flanged butterfly valve has flanges on it, with the flanges at both ends of the valve being connected to the pipe flanges via bolts.