The disc of the butterfly valve is a disc that rotates around an axis in the valve seat. The size of the rotation angle is the opening and closing degree of the valve. Its advantages are light weight, simple structure, less material than other valves, quick opening and closing, both cutting and throttling, small fluid resistance, labor-saving operation, and can be made into a large diameter. Butterfly valves are widely used in hot water pipelines. Where the butterfly valve can be used, it is best not to use the gate valve, because the butterfly valve is more economical than the gate valve and has better regulation.
