What is impeller back clearance?

Impeller back clearance refers to the space or gap between the back of an impeller and the casing or shroud within a pump or turbine. This clearance is crucial as it can impact the efficiency, performance, and operational stability of the machine. Adequate back clearance helps to prevent recirculation of fluid, reduces wear, and minimizes energy losses, while insufficient clearance can lead to increased friction and potential damage. Proper design and maintenance of this clearance are essential for optimal functioning of the equipment.