What Does it Mean to Say that a Pump is Centrifugal?
A centrifugal pump is one that uses the rotation of an impeller to impart energy into a liquid.
The word centrifugal is defined as: “moving outward from the center.”
When a centrifugal pump impeller rotates it draws liquid into the center of the impeller and the liquid exits the impeller from the outer edge of the impeller. In this way, a pump impeller is centrifugal: liquid is drawn into the center and then pushed out from the center.
In the past, the term centrifugal has been applied to all pump designs that use the rotation of an impeller to impart velocity into a liquid. However, more recently there has been a move to be more technically accurate by referring to pumps with a very high specific speed as mixed-flow and axial-flow pumps. The term rotodynamic has been put forward by the Hydraulic Institute as an umbrella term that can be applied to any type of pump that use rotation to impart velocity in a liquid. Therefore, the rotodynamic umbrella includes centrifugal pumps as well as mixed and axial-flow designs that don’t technically meet the definition of being centrifugal.