Why do centrifugal pumps need to be operated in parallel or in series?

The purpose of parallel or series operation of centrifugal pumps is to meet different flow and lift requirements, and to increase the total flow or lift through the combination of multiple pumps.

Specifically, series operation can connect multiple centrifugal pumps in the same pipeline, connecting the outlet of the previous stage pump with the inlet of the next stage pump, thereby superimposing the heads of different pumps. The total head is increased while the flow rate remains unchanged. This method is suitable for situations where the water level is large and the flow demand is small, such as the water supply system of high-rise buildings.

Parallel operation is to connect multiple centrifugal pumps to the same pipeline at the same time, connect their inlets, and the outlets flow into different parts of the pipeline. This method can superimpose the flows of different pumps to increase the total flow without changing the head. This method is suitable for occasions with low water level and large flow demand, such as conveying systems in industrial production processes.

It should be noted that when operating centrifugal pumps in parallel or series, the following points need to be noted:

Confirm the performance parameters of each pump, the pressure loss and flow rate of the pipeline system Whether the changes and other factors are suitable to avoid damage to the pump or instability of the system due to mismatch of pump parameters or unreasonable piping system.

Confirm whether the pipe diameter, interface size, etc. of the inlet and outlet of each pump are the same to avoid flow bottlenecks or flow losses caused by mismatched pipelines.

For series operation, it is necessary to pay attention to whether the inlet of each pump can absorb water normally to avoid idling or evacuation.

For parallel operation, it is necessary to pay attention to whether the flow rate of each pump is equal to avoid affecting the normal operation of the system due to unbalanced flow rate.

In short, the parallel and series operation of centrifugal pumps can increase the flow or head according to different needs, but reasonable selection and configuration need to be carried out according to the specific situation to ensure the normal operation of the pump and the stability of the system.