The GAIRUI Lubricated Inverted Pressure Balance Plug Valves is a valve that opens and closes the closing part (the stopper) rotating around the center line of the valve body. Plug valves are mainly used for cutting, distributing and changing the direction of media flow in pipelines. Plug valves are the earliest valves used in history. Because of its simple structure, fast opening and closing (the 1/4 circles of the plug can complete the opening and closing action), the operation is convenient, and the fluid resistance is small, so far it is widely used. At present, it is mainly used for low pressure, small caliber and medium temperature. The stopper and plug body of the stopcock is a good conical body.