There are generally three types of pump losses: hydraulic, volumetric, and mechanical. Hydraulic loss, also known as flow loss, is the difference between the theoretical lift and the actual lift. It includes three aspects. (1) Since the actual number of impeller blades is not infinite, the liquid does not flow strictly along the blade's orbit, and circulation occurs to produce eddy current loss; (2) resistance loss; and (3) impact loss. Volume loss is the energy loss caused by the flow leakage. Mechanical loss is due to wear and tear on bearings, sealing materials, and both sides of the impeller.