V A centrifugal pump uses the principle of centrifugal force to move water through plumbing systems and hoses. The centrifugal pump spins a shaft at high speed which rotates an impeller, creating a vacuum through centrifugal force that pulls the water. A mechanical seal positioned just behind the spinning impeller on the motor shaft prevents water from entering the delicate electrical motor of the pump. Replacing these mechanical seals involves opening the pump system, removing the impeller from the pump's shaft and sliding the old seal off the shaft