Sewage pumps belong to the scope of centrifugal pumps, and their structure and principle are the same as general centrifugal pumps.

Sewage pumps also have their own structural characteristics. The head of sewage pumps is not high, and due to the large amount of debris in the sewage, the clearance between the impellers is larger than that of clean water pumps. The faults that sewage pumps are prone to are similar to those of general centrifugal pumps, as the impeller wears out quickly due to the pumping of sewage.

Ordinary water pumps are designed to achieve efficiency, which means that the hydraulic structural parameters of water pumps are a combination of efficiency. The efficiency of sewage pumps and pumps with special requirements cannot exceed the efficiency of clean water pumps during the same period.

The main reason why sewage pumps have lower efficiency than clean water pumps is that their flow channels have been widened. The decrease in efficiency is mainly related to the degree of widening. The widening of the sewage pump channel is to prevent blockage.