Centrifugal pumps operate using kinetic energy to move fluid, utilizing an impeller and a circular pump casing. A vacuum is created in the pump which draws fluid to the impeller by suction. The impeller produces liquid velocity and the casing forces the liquid to discharge from the pump, converting velocity to pressure. This is accomplished by offsetting the impeller in the casing and by maintaining a close clearance between the impeller and the casing at the cutwater. By forcing fluid through without cupping it, centrifugal pumps can achieve very high flow rates.