Butterfly valve is a switch-type butterfly valve, which is mainly composed of valve body, valve plate, valve shaft, sealing ring and other parts. Metal-to-metal contact is used between the valve body and the valve shaft, and the rotation of the valve shaft drives the valve plate to open and close. The structure of the butterfly valve is explained in detail as follows:

1. Valve body: The valve body is the main body of the butterfly valve and is made of cast iron, cast steel, stainless steel and other materials. The interior of the valve body has a circular channel for the passage of fluid. There are inlets and outlets at both ends of the valve body for connecting pipes and other valves.

2. Valve plate: The valve plate is the switching part of the butterfly valve and is made of wear-resistant materials. The valve plate can rotate driven by the valve shaft to open or close the valve. The shape of the valve plate is circular. When rotated to a certain angle, the fluid can be cut off or only a small flow of fluid can pass.

3. Valve shaft: The valve shaft is the transmission part of the butterfly valve and is made of steel, stainless steel and other materials. One end of the valve shaft is in contact with the valve body, and the valve plate is opened and closed by rotating the valve shaft. The other end extends out of the valve body and is used to connect the transmission mechanism or manual mechanism.

4. Sealing ring: The sealing ring is the sealing part of the butterfly valve and is made of rubber, plastic and other materials. The sealing ring can be installed under the valve plate or inside the valve body to prevent fluid from leaking from the inside of the valve. The sealing ring can be designed as a one-way seal or a two-way seal to ensure that the valve can only close in one direction.