Butterfly valve has simple structure, only by a few parts, material consumption province; Small volume, light weight, small installation size, small drive moment, operation is simple, rapid, and only need to rotate 90 ° can rapid opening and closing; And at the same time also has a good flow regulating function and close the seal characteristics, in the field of large and medium size, the use of low and medium pressure, butterfly valve is the dominant form of the valve. Butterfly valve in the fully open position, the butterfly plate thickness is medium flows through the body when the only resistance, thus produced by the valve pressure drop is small; it has good flow control characteristics. Butterfly valves have a seal and metal seal two kinds of seal type. Elastic sealing valve, sealing ring can be embedded in the body or attached to the butterfly plate peripheral.
