The plug is a refractory material tiles in the lower end of the plug rod and the torque tiles. When it is not cast, it blocks the water outlet to ensure that there is no leakage. When the casting is poured, the plug and the water mouth brick create a gap, and the steel is flowing from the water. The control of the stuffed rod is high, and the amount of flow of the steel water can be adjusted. The plug and the rod core can be fixed with threads or pin. The plug can be a sticky, non-high aluminum and tar-dip impregnated non-high aluminum.