The butterfly valve, also known as the flap valve, is a simple regulating valve. The butterfly valve that can be used for the switching control of the low-pressure pipeline medium means that the closing member (valve or disc) is a disc that rotates around the valve shaft to achieve opening and closing. a kind of valve.Valves can be used to control the flow of various types of fluids such as air, water, steam, various corrosive media, mud, oil, liquid metals, and radioactive media. Mainly cut and throttle on the pipeline. The butterfly valve opening and closing member is a disc-shaped butterfly plate that rotates around its own axis in the valve body to achieve the purpose of opening and closing or adjusting.