Butterfly valve has simple structure, small volume, light weight, only by a few parts. And only need to rotate 90 ° can rapid opening and closing, simple operation, at the same time, the valve has good flow control characteristics. 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.
Using metal seal valve generally live longer than elastic sealing valve, but it is hard to be completely sealed. Metal sealing can adapt high working temperature, elastic seal has the defect of being limited by the temperature.
If required butterfly valve used as flow control, mainly is the right choice of the size and type of valve. The structure and principles of butterfly valve is especially suitable for production of large diameter valves. Butterfly valve not only in the oil, gas, chemical industry, water treatment and other general industrial used widely, but also applied to the cooling water system of thermal power plants.
Commonly used butterfly valve, which has two kinds of the wafer butterfly valve and flanged butterfly valve. Wafer butterfly valve with stud connection in place between two pipe flanges and flanged butterfly valve is a valve with flange, bolts on the valve flange connection on the pipe flange on both ends.