Working principle of butterfly valve

The working principle of butterfly valve is to change the flow rate and direction of fluid by rotating the valve. A butterfly valve consists of a valve body, a valve seat, a valve stem, and a valve disc.

When the butterfly valve is closed, the valve disc seals against the valve seat, preventing fluid from passing through the valve body. When the butterfly valve needs to be opened, the valve stem will rotate the valve disc to open the valve. The fluid will then flow through the valve disc and pass through the flow channels in the valve body.

The advantages of butterfly valves are that they are very simple, space saving, have quick closing and starting operations, and can be used in most media. However, butterfly valves are not suitable for applications in high-pressure and high-temperature environments.

The fully open and fully closed butterfly valve is usually less than 90 °, and the butterfly valve and stem themselves do not have self-locking ability. In order to position the butterfly plate, a worm gear reducer should be installed on the stem. By using a worm gear reducer, not only can the butterfly plate have self-locking ability to stop at any position, but it can also improve the operational performance of the valve. The characteristics of industrial butterfly valves include high temperature resistance, high pressure range, large nominal diameter, carbon steel valve body, and metal ring instead of rubber ring for valve plate sealing. Large high-temperature butterfly valves are manufactured by welding steel plates and are mainly used for flue gas ducts and gas pipelines for high-temperature media.