How To Use A Self-priming Pump

Jan 11, 2026

Self priming pumps belong to self-priming centrifugal pumps, which have the advantages of compact structure, easy operation, stable operation, easy maintenance, high efficiency, long service life, and strong self-priming ability. There is no need to install a bottom valve in the pipeline. Before operation, it is only necessary to ensure that a certain amount of liquid is stored in the pump body. Different liquids can use self-priming pumps made of different materials.

 

Preparation and inspection work before starting

 

1. According to the working and operating conditions of the pump, calcium based butter and No. 10 engine oil should be used for lubrication. If a butter lubricated pump is used, butter should be regularly added to the bearing box. If the oil level is insufficient, the pump should be fully lubricated.

2. Check if the liquid storage inside the pump casing is higher than the upper edge of the impeller. If it is insufficient, the liquid can be directly injected into the pump body from the filling port on the pump casing. It should not be started when the liquid storage is insufficient, otherwise it will not work properly and the mechanical seal may be damaged.

 

 

3. Check whether the rotating parts of the pump are stuck or bumped.

4. Check for loose nuts at the pump body feet and connections.

5. Check the coaxiality and parallelism between the pump shaft and the motor shaft.

6. Check if there is any air leakage in the inlet pipeline, and if there is any, try to eliminate it.

7. Open the valve of the suction pipeline and slightly open (not fully open) the outlet control valve.

 

Start up and operation

 

1. Tap the self-priming pump and pay attention to whether the direction of the pump shaft is correct.

2. Pay attention to any abnormal sounds and vibrations during rotation.

3. Pay attention to the readings of the pressure gauge and vacuum gauge. After starting, when the readings of the pressure gauge and vacuum gauge fluctuate for a period of time and stabilize, it indicates that the pump has been filled with liquid and normal infusion operation has begun.
4. Before the pump enters normal infusion operation, during the self suction process, special attention should be paid to the increase in water temperature inside the pump. If this process is too long and the water temperature inside the pump is too high, the pump should be stopped to check the cause.

 

5. If the temperature of the liquid inside the pump is too high and causes difficulty in self-priming, it can be temporarily stopped. The liquid in the discharge pipeline can be used to flow back into the pump or to add liquid directly to the pump body through a storage port to cool down the liquid inside the pump, and then it can be started.
6. If there is strong vibration and noise during the operation of the pump, it may be caused by cavitation. There are two reasons for cavitation: one is that the inlet pipe flow rate is too high, and the other is that the suction stroke is too high. 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 promptly eliminated; When the suction distance is too high, the installation height of the pump can be appropriately reduced.
7. When the pump stops for some reason during operation and needs to be restarted, the outlet control valve should be slightly opened (not fully closed), which is beneficial for the gas to be discharged from the discharge outlet during the self-priming process and ensures that the pump starts under lighter loads.
8. Pay attention to checking for leaks in the piping system.