Correct Usage Methods for Self-Priming Pumps

1. Pre-Start Checks  

- Depending on the pump’s operating conditions, this series of self-priming pumps uses either high-quality calcium-based grease or No. 10 machine oil for lubrication. If it uses grease, regularly add grease to the bearing housing. If it uses oil, top it up if the level is low.  

- Check if the liquid in the pump casing is above the top edge of the impeller. If not, pour liquid into the pump through the filling port on the casing. Never start the pump with insufficient liquid, as it won’t work properly and may damage the mechanical seal.  

- Check if the rotating parts are jammed or making contact.  

- Check if the pump’s base feet and all connection nuts are loose.  

- Check the coaxiality and parallelism of the pump shaft and the motor’s main shaft.  

- Check the inlet pipe for air leaks. If leaks exist, fix them.  

- Open the inlet pipe valve and slightly open (don’t fully open) the outlet control valve.  

2. Starting and Operation  

- Give the pump a quick test run to check if the impeller is turning in the correct direction.  

- Listen for unusual noises or vibrations while it’s running.  

- Monitor the pressure gauge and vacuum gauge readings. After starting, once the readings stabilize after a short fluctuation, the pump has drawn in liquid and is operating normally.  

- During the self-priming process (before normal pumping begins), keep an eye on the water temperature inside the pump. If the process takes too long and the water gets too hot, stop the pump to check why.  

- If high liquid temperature is causing self-priming issues, temporarily stop the pump. Let liquid from the discharge pipe flow back into the pump or add liquid through the filling port to cool it down, then restart.  

- If the pump vibrates violently or makes noise during operation, it may be cavitating. Cavitation has two causes: excessive inlet flow rate or too high a suction lift. If the flow rate is too high, adjust the outlet control valve to increase the pressure gauge reading. If the inlet pipe is blocked, clear it immediately. If the suction lift is too high, lower the pump’s installation height.  

- If the self-priming pumps stops working and needs to be restarted, keep the outlet control valve slightly open (not fully closed). This helps air escape through the discharge port during self-priming and lets the pump start under a lighter load.  

- Check the pipeline system for leaks.  

3. Stopping the Pump  

- First, close the gate valve on the discharge pipe.  

- Stop the pump’s motor.  

- In cold weather, drain all liquid from the pump casing and the bearing housing’s cooling chamber to prevent freezing and cracking.