A multistage centrifugal pump is a type of pump that features two or more impellers stacked together on the same shaft with a shared motor, as if connected in a series.
Each impeller and volute (or stage) that the water flows through will boost the pressure of the water, so the more impellers and the more stages, the greater the pressure discharged. No matter how many impellers you add, the flow is constant; should flow change then you’ll need a variable frequency drive.
The multistage centrifugal pump’s high pressure: flow ratio is useful for applications that require high pressure to get a small amount of liquid. For example, when you need to pump water up to reach the top apartment in a tall block of flats.
Advantages of multistage pumps
Multistage pumps are very efficient as they have several smaller impellers to allow smaller tolerances. With just one motor and one shaft, every impeller added has minimal energy loss for each increase in stages. There will also be lower noise levels at each additional stage than that of a single stage pump. In general, any application that requires high output or high pressure would benefit from a Multistage Pump, whether horizontal or vertical.
When choosing between setting up multiple centrifugal pumps in a series or installing a multistage pump, there are five great reasons why you should choose a multistage centrifugal pump:
1. Greater efficiencies
A multistage centrifugal pump has small impeller diameters and clearances that allow improved performance and efficiencies at less horsepower. With just one motor, energy usage is lower than most alternatives.
2. Less space
When using a vertical multistage centrifugal pump, you can save on floor space as the pump has a shaft that runs vertically, with stages stacked on top of each other.
3. Higher pressure
A multistage pump has a small motor size (and uses less energy) while allowing increased pressure at each stage. However, you may need a variable frequency drive to adjust pressure build should the application require constant flow.
4. Lower head for each volute or stage
Lower head can be achieved despite smaller impeller size, which results in less leakage. This means a multistage centrifugal pump can pump a fluid to greater heights than another alternative.
5. Cost savings
Multistage centrifugal pumps may cost a little more upfront than other options, but their running costs are less.
The main disadvantage of multistage pumps is that while their small tolerances ensure hydraulic efficiencies, this makes them unsuitable for pumping solids or abrasive materials.
So, should you attempt to generate more head with a series of single-stage pumps or choose a multi-stage centrifugal pump? Call our toll-free number 1-800-367-4180 for advice from our experts, who are on hand to help you choose, install, and maintain a variety of equipment. And to answer questions about things you’ve previously tried gone wrong.