Why might a seal in a centrifugal pump be necessary?

A seal in a centrifugal pump is crucial primarily to prevent fluid from leaking out around the shaft. The design of a centrifugal pump involves a rotating shaft that moves fluid from the inlet to the discharge. If there were no seal, the pressure created by the fluid could cause leaks around the shaft, leading to fluid loss, potential environmental hazards, and a decrease in the overall effectiveness of the pump system.

Seals maintain the integrity of the pump's operation by ensuring that fluids are contained within the system, thus enabling optimal performance. Proper sealing also minimizes the risk of contamination in the fluids being pumped, which could compromise both the pump's efficiency and the integrity of the process it supports.

While thermal expansion is a consideration in pump design, the primary role of the seal is focused on preventing leaks. Although increasing pressure and improving efficiency are important characteristics of pump performance, they are not directly accomplished by the seal itself but rather through the overall configuration and function of the pump.