During the operation of centrifugal pumps, it is not allowed for the water pump to run idle. Many users are hesitant about the phenomenon of idle running of centrifugal pumps because they do not understand the reasons for it and do not know how to solve it effectively. In fact, centrifugal pumps will not cause damage if they idle for a short period of time (within 1 minute).

The reasons for centrifugal pump idling are: insufficient inlet medium of the water pump or insufficient inlet pressure, or blocked inlet pipe of the water pump, or incomplete air discharge in the water pump chamber.

When the centrifugal pump is idling, the impeller has little or no contact with the medium, making it unable to work effectively and the liquid cannot be transported out normally. These are all useless efforts. Due to the lack of effective work, the load on the motor is very small, and the generated current is also very small, which has little impact on the motor. The impact of the pump idling on the pump is indeed fatal. Idle water pumps are prone to cavitation, causing damage to the pump body and flow components; The mechanical seal form or packing seal form of the idle water pump will not receive liquid lubrication, resulting in dry grinding and rapid damage; The rotor components and pump body of the idle water pump generate heat without cooling liquid, and the narrow gap positions (such as sealing rings) are easily bitten due to thermal expansion and contraction; The balance plate of an idle multi-stage centrifugal pump is not lubricated by anyone, and the balance plate will quickly be burned or damaged.

It is recommended to upgrade the design of centrifugal pumps to a higher level for warning and maintenance of centrifugal pump idling:

1、 Process the various clearance positions of the centrifugal pump, expand them under allowable conditions, and prevent them from biting;

2、 Special processing techniques such as quenching, tempering, and heat treatment are applied to the shaft of the centrifugal pump to increase its hardness. Materials with low flexibility are used to prevent significant swinging and biting during idle operation;

3、 Use machine seals and packing chambers that do not require lubrication from liquid media; 4、 Choose sealed self-lubricating bearings that do not require refueling.

The pump chamber of a horizontal self-priming centrifugal pump has increased in volume compared to other centrifugal pumps, providing a location for water storage. Before the self-priming centrifugal pump works normally, the chamber should be filled with liquid. There is a period of self-priming before operation, during which air is continuously discharged outside the pump body. This period belongs to partial idling.

Set up an idle sensing system. Real time monitoring of the water pump is carried out through modern equipment. When the centrifugal pump runs idle, it will immediately sound an alarm and automatically shut down to protect the safety of the unit.