A centrifugal pump is a machine that uses rotation to impart velocity to a liquid and then converts that velocity into flow.

Let’s break that definition down into its components so that we can consider each one in turn:

1. A centrifugal pump is a machine.
2. A centrifugal pump uses rotation to impart velocity to a liquid.
3. A centrifugal pump converts velocity into flow.

“A centrifugal pump is a machine.” Every centrifugal pump includes an assembly of mechanical components that make operation of the pump possible. This mechanical assembly includes the pump shaft mounted on bearings, the sealing mechanism that keeps the pump from leaking excessively, structural components designed to handle the stresses and loads imposed on the pump during operation, and wear surfaces that allow the pump to be repaired and returned to its original specifications.

“A centrifugal pump uses rotation to impart velocity to a liquid.” Every centrifugal pump includes an impeller. The impeller is the hydraulic component that rotates to impart velocity to the pumped liquid.

“A centrifugal pump converts velocity into flow.” Every centrifugal pump includes a casing. The casing is the hydraulic component that captures the velocity imparted by the impeller and directs the pumped liquid to the pump discharge point.

At the most fundamental level, a centrifugal pump consists of just these three components:

1. An impeller that rotates and imparts velocity to a liquid.
2. A casing that captures the velocity generated by the impeller and transforms that velocity into a stable flow.
3. An assembly of mechanical components that makes it possible for the impeller to be rotated within the pump casing.