1.Single-stage pump means that the pumps have only one impeller, and the highest lift is 125 meters;
2.Multi-stage pump means the pumps have two or more impellers. They can absorb and pressure water in different levels and times, so that the water can be ascend to a high position. The lift can be changed by increasing or decreasing the number of stages of pump impeller.In the case of single-stage pump head needs to be equipped with two motors, multi-stage 
pump can increase the number of impellers to equipped with four motors, which can improve the life of the pump and reduce unit noise.
3.When actual lift of the pump is less than 125 meters, it can accord to the area of the pumping station, pump prices (multi-stage pump is generally higher than the price of a single-stage pump), and other factors considered in the selection of a single-stage or multi-stage pump.
