The venting plug (commonly known as the nozzle) of the 10SH-9 centrifugal clean water pump of our factory is a hexagonal screw plug (Fig. 1). Before the pump is working, it is generally necessary to fill the pump body through the water inlet. During the filling process, the operator has to use a wrench to loosen the hexagonal plug 2 and let the air out of the pump body and the water pipe. After the water is poured into the pump body 1, the hexagonal screw plug must be tightened with a wrench to work.