The plug valve is a valve that uses the plug body with a hole as the opening and closing part and realizes the opening and closing action through the rotation of the plug body and the valve stem. Plug valve structure is simple, open and close quickly, fluid resistance is small, in recent years, as one of the earliest valves used by people in history not only has not been replaced by ball valves and other new valves, but the market is becoming more and more popular trend.