What is the major component of a centrifugal pump that provides velocity to the water?

• A. Impeller
• B. Casing
• C. Shaft
• D. Diffuser

Answer: (A)

The impeller is the part that actually puts velocity into the water. As the impeller spins, its blades fling water outward from the center, imparting kinetic energy and increasing the water’s speed as it leaves the eye of the pump. That rapid movement is the velocity the pump adds to the fluid. The casing (volute) or diffuser then slows that high velocity and converts much of it into pressure to push water through the discharge, while the shaft simply transmits power to turn the impeller. So the component that directly adds the water’s velocity is the impeller.