Industrial slurry pump

Multistage Pump Guide & Multistage Centrifugal Pump Design

What is the difference between single and multistage pumps?

The primary difference between single and multistage pumps is their impellers and how this affects operation. Whereas a single stage pump has only one impeller rotating around the shaft, multistage pumps have two or more.

Pressure capabilities

The multiple impellers of a multistage centrifugal pump are all installed and rotated on the same shaft, and essentially act like separate pumps. This mean that as the flow progresses from one stage to the next, the head increases approximately by the same amount, resulting in the multistage pump design having much higher pressure capabilities than a single impeller is able to alone. Multistage centrifugal pumps are often selected when the pressure requirements of the application exceed the capabilities of a single stage pump. Single stage centrifugal pumps are on the other hand the better suited solution in higher flow, lower pressure installations.

Efficiency

As multistage pumps reply on multiple impellers used to impart energy into the fluid being handed, each impeller can be smaller in diameter than it would be alone and can operate with tighter clearances between the impeller and volute. These smaller tolerances mean that each impeller operates closely to its best hydraulic efficiency. The result of this is that multistage centrifugal pumps are able to achieve higher performance with a smaller motor size and using less energy.

Typical applications of a multistage centrifugal pump

Due to the tight impeller clearance with the pump volute, multistage pumps are unable to handle solids and abrasive content unless they are oversized, which is why they are generally used with water and other low viscosity fluids. This combined with their high pressure range, makes multistage water pumps popular in applications including: Boiler feed, Reverse osmosis, Water supply boosting, Irrigation, Fire fighting, Heating/cooling conditioning, Water circulation