Why can't the centrifugal pump idle?

Hazards of idling of centrifugal pump: 

1. When the centrifugal pump is idling, the impeller has no or little contact with the medium, cannot work effectively, and the liquid cannot be transported out normally, all of which are useless. Due to no effective work, the load borne by the motor is very small, and the generated current is very small, which has little impact on the motor. The impact of the pump idling on the pump is really fatal. 

2. Idle water pump is prone to cavitation, causing damage to pump body and flow passage parts; The mechanical seal form or packing seal form of the idle water pump will not be lubricated by the liquid, resulting in dry grinding and fast damage; 

3. Idling pump rotor parts and pumps will generate heat without liquid cooling, and the narrow clearance positions (such as sealing rings) are easy to be seized due to thermal expansion and contraction; 

4. The balance plate of the idle multi-stage centrifugal pump is not lubricated by water, and the balance plate will be burned and damaged soon. 

Early warning and maintenance suggestions for idling of centrifugal pump: 

1. Treat all clearance positions of the centrifugal pump and expand it under allowable conditions to prevent seizure; 

2. The shaft of centrifugal pump shall be subject to special process treatment, tempering, heat treatment, etc. to improve the hardness. Materials with low flexibility shall be used to prevent seizure due to large swing during idling; 

3. Use mechanical seal and packing chamber not lubricated by liquid medium; 

4. Sealed self-lubricating bearings without oil shall be selected. 

The pump cavity of horizontal self-priming centrifugal pump is enlarged compared with other centrifugal pumps, so there is a place for water storage. Before the self-priming centrifugal pump works normally, the cavity shall be filled with liquid. There is a period of self-priming time before operation, during which the air is continuously discharged to the pump body, and this period belongs to partial idling. 

Set idle sensing system. The water pump is monitored in real time by modern equipment. When the centrifugal pump runs idly, it will immediately alarm and automatically stop to protect the safety of the unit.