Butterfly valve is refers to the closing member for disc, around the valve spindle rotation to achieve open and closed valve, in pipeline mainly on cutting and throttling action. Butterfly valve opening and closing a is a disc butterfly plate, in the body around its own axis rotation, so as to achieve the purpose of opening and closing or regulation. Butterfly valve fully open to all is usually less than 90 °, butterfly valve and butterfly bar itself has no self-locking ability, in order to butterfly plate positioning, the valve lever on the worm reducer.

The worm reducer, not only can make butterfly plate with self-locking ability, make butterfly plate stop at any position, but also can improve the operating performance. The characteristics of the industrial special butterfly valve can high temperature, apply pressure range is higher, the valve nominal diameter is big, the body using carbon steel manufacturing, valve plate seal using metal ring instead of rubber ring. Large high temperature butterfly valve USES the steel plate welding manufacturing, mainly used for high temperature medium of smoke duct and gas pipe.