How To Set Impeller Clearance | Video

MP Pumps demonstrates how to set impeller clearance on an MP Pumps HTO hot oil centrifugal pump. After adjustment, the mechanical seal spring and the thermal growth rate of the drive sleeve material will cause the clearance to be set appropriately.


Impeller clearance refers to the distance between the impeller vanes and casing. Impeller clearance is dependent on a number of factors, such as type of bearings, contamination of fluid handled, clearance gap cavitation, and machine specifications.

Centrifugal pumps work by introducing fluid to a rapidly spinning rotor, called an impeller, which is surrounded by a casing. The rotation of the impeller creates centrifugal force, which is transferred to the fluid upon contact with the impeller. The fluid is then expelled through a suction port, moving the fluid to the outside of the casing. The fluid then exits a discharge port, where the centrifugal force is transferred into pressure.

How does a Centrifugal Pump work?

Hot oil centrifugal pumps are typically designed for extremely hot fluids, such as hot water up to 400°F and hot oils up to 750°F. MP Pumps HTO centrifugal pumps are a patented product designed to use ambient air temperature around the mechanical seal to reduce seal temperature, which greatly improves seal life.