Precautions for starting a self-priming pump

Firstly, different self-priming pumps have distinct design features, and operations must first be carried out in accordance with the manufacturer’s requirements； Secondly, check for any leaks or air intake that could affect the automatic start function; if so, find a way to address them.

1. Start the self-priming pump manually, and pay attention to whether the rotation direction of the pump shaft is correct. Pay attention to any abnormal noises or vibrations during rotation. 2. Pay attention to the readings on the pressure gauge and vacuum gauge. Once these readings stabilize after some fluctuation following startup, it indicates that liquid has filled the pump, and normal pumping operation can proceed. 3. During the priming process, before the self-priming pump starts operating normally for liquid transfer, special attention should be paid to the increase in water temperature inside the pump. If this process takes too long and the water temperature inside the pump becomes too high, the pump should be stopped to determine the cause. 5. If the temperature of the liquid inside the pump is too high, causing difficulties in self-priming, the pump can be stopped temporarily. The liquid in the discharge pipeline can be allowed to flow back into the pump, or liquid can be directly added to the pump at the reservoir port, in order to lower the temperature of the liquid inside the pump. Once that is done, the pump can be restarted. 5. If a self-priming pump experiences severe vibration and noise during operation, it may be due to cavitation. There are two reasons for cavitation: one is an excessive flow velocity in the inlet pipe, and the other is an overly high suction lift. When the flow rate is too high, the outlet control valve can be adjusted to increase the pressure gauge reading; if there is a blockage in the inlet pipeline, it should be removed promptly ； When the suction lift is too high, the installation height of the pump can be appropriately reduced. 6. When a self-priming pump stops operating for some reason and needs to be restarted, the outlet control valve should be left slightly open (not fully closed). This facilitates the expulsion of gas from the outlet during the priming process, while also ensuring that the pump starts under reduced load. For self-priming pumps, make sure to check the piping system for any leaks