1. Lubricating water ring vacuum pump Since the vacuum pump and motor are integrated, only the motor bearings need to be lubricated. Under normal operating conditions (50Hz), motor bearings with class B insulation must be cleaned and added after about 8000 hours or a year. 2. Maintenance of water ring vacuum pump (1) Regularly check whether the bolts are loose, whether the air pipe leaks, whether the packing seal is fastened, whether the packing seal leaks, and whether the rotating parts have friction sound or other noise. If so, stop or repair or replace parts. (2) There shall be no sand or debris in the water. (3) If hard water is used as the working fluid, the water must be softened or the pump must be washed with solvent frequently. It is usually immersed in 10% oxalic acid for 30 minutes or in detergent used in industrial boilers for 30 minutes to remove calcium carbonate. (4) If the pump is not used for more than two weeks, drain the water in the pump, fill the suction port of the pump with 0.5L antirust agent or engine oil, and gently push the pump for less than 1s. (5) If the water ring vacuum pump is used where it may freeze at low temperature, antifreeze and corrosion-resistant working fluid, such as mineral oil, shall be used. Drain the water in the pump chamber after each use. (6) If the water ring vacuum pump does not work for a long time, drain the water in the pump and add anti rust liquid to protect the pump.