What is the primary function of the impeller in a centrifugal pump?

• A. To seal the pump
• B. To regulate temperature
• C. To generate velocity
• D. To measure flow rate

Answer: (C)

The primary function of the impeller in a centrifugal pump is to generate velocity in the fluid by transferring mechanical energy from the motor into the liquid. As the impeller spins, it pushes the liquid outward, increasing its speed (kinetic energy). That higher velocity is then converted into pressure as the fluid is directed through the diffuser or volute, enabling the pump to move the fluid through the system. Sealing the pump, regulating temperature, and measuring flow rate are handled by other components or instruments, not by the impeller. So the impeller’s main job is to impart velocity to the fluid.