Technical selection considerations for submersible pumps

The ideal choice of submersible pump is a prerequisite for the correct use of submersible pump.

There are many specifications and models of submersible pumps, and their usage conditions are not the same. If the selection is not reasonable (such as high or low head, large or small flow rate, which not only causes waste of financial resources and power, but also reduces efficiency and even damages the unit and well), submersible pumps cannot work normally.

The principle of selection is that the flow rate and head can meet the actual needs, with high efficiency and good economic performance. The flow rate selection should be smaller than the inflow of the well during the dry season, which is beneficial for the reliable operation of the submersible pump.

Pump selection mainly includes the following aspects:

1: Select pump type based on wellbore diameter

There are 7 specifications of wellbore pipe diameters in China, including 6, 8, 10, 12, 16, and 20 inches. In order to smoothly insert the submersible pump into the well casing, it is required that the maximum diameter of the submersible pump should be smaller than the diameter of the well casing, and the integrity of the wellbore should also be considered. If the wellbore is inclined or misaligned, a submersible pump with a smaller diameter should be selected. However, the general principle is to vertically lower the submersible pump into the well, so that the pump can rise and fall freely.

2: Select pump type based on the minimum water inflow of the well

Generally speaking, the water inflow of each well is different in different periods, and the dry season is relatively small. Therefore, the flow rate of the selected pump should be selected based on the water inflow of the well during the dry season. The selected pump flow rate must be less than or equal to the water inflow of the well during the dry season, so that the pump can operate normally in all periods.

3: According to the head of the submersible pump

The head of a pump consists of three parts: the lifting height, the working pressure at the outlet, and the loss of the water supply pipeline. The reasonable selection of pump head is mainly based on the actual operating environment requirements, while considering the loss of water transmission pipelines. The loss of water transmission pipelines is mainly affected by factors such as the flow rate of liquid in the pipeline, pipeline diameter, pipeline material, gate valves, and elbows. For detailed introduction, please refer to the relevant water supply and drainage manual.

4: Other considerations for selecting submersible pumps

(1) When selecting a submersible pump model, refer to the product performance technical data sheet. There are three sets of data for flow rate and head, with the middle data being the design point flow rate and head, and the two ends being the data for operating within the range of 0.7 to 1.2 times the rated flow rate. According to the required flow rate and head, the submersible pump should be selected to operate within the operating range, which can ensure the service life of the submersible pump and also ensure that it operates within the high-efficiency range.

(2) In the product performance technical data sheet, if a suitable pump model cannot be found, a submersible pump with similar performance can also be selected (please contact us).

(3) After determining the model of submersible pumps, the number of submersible pumps selected should be economical and reasonable. In order to facilitate management and maintenance, as well as the exchange of (vulnerable) parts, submersible pumps of the same model should be selected as much as possible.