Butterfly valve, a type of throttle valve, is an important device in water supply and drainage pipeline systems. With the progress of industrial technology, different requirements are put forward for the structure and performance of butterfly valves.The butterfly valve opening and closing member is a disc shaped butterfly plate that rotates around its own axis within the valve body to achieve the purpose of opening and closing or adjusting. The butterfly valve is usually less than 90 ° from fully open to fully closed,Industrial butterfly valves are characterized by high temperature resistance, high pressure range, large nominal diameter, and carbon steel body.