The disc of a butterfly valve is installed in the diameter direction of the pipeline. Inside the cylindrical channel of the butterfly valve body, the disc-shaped butterfly plate rotates around its axis. The rotation angle is between 0° and 90°. When rotated to 90°, the valve is in a fully open state.
The butterfly valve has a simple structure, small size, and light weight, consisting of only a few parts. Moreover, it can be quickly opened and closed by just rotating 90°, making the operation simple. Meanwhile, this valve also has good fluid control characteristics. When the butterfly valve is in a fully open position, the thickness of the butterfly plate is the only resistance when the medium flows through the valve body. Therefore, the pressure drop produced by passing through this valve is very small, so it has good flow control characteristics. Butterfly valves have two types of sealing systems: elastic seal and metal seal. For elastic seal valves, the seal ring can be embedded on the valve body or attached to the periphery of the butterfly plate.