If your business needs to move water, chemicals, or process fluids efficiently, chances are you’ve come across a single stage centrifugal pump — one of the most widely used pump types in commercial and industrial systems. But how does a centrifugal pump work, and how do you know if a single stage design is enough for your application, or if you actually need a multistage pump instead? In this guide, you’ll walk through exactly how a single stage centrifugal pump works, where it performs best, and how it compares to multistage alternatives — so you can make the right call for your next project.
What Is a Single Stage Centrifugal Pump?
A single stage centrifugal pump is a pump design that uses only one impeller to move fluid through the system in a single pass. “Single stage” simply refers to the number of impellers doing the work — as opposed to a multistage centrifugal pump, which uses two or more impellers arranged in series to build higher pressure.
Because of its simple internal design, a single stage centrifugal pump is typically your most cost-effective, easiest-to-maintain option — ideal whenever your application needs moderate pressure and doesn’t require multiple pressure-boosting stages.
How Does a Centrifugal Pump Work? The Working Principle Behind Single Stage Pumps
To understand where a single stage pump fits, it helps to understand how does a centrifugal pump work at a mechanical level. The centrifugal pump working principle relies on converting rotational energy into fluid velocity, then converting that velocity into pressure. In a single stage centrifugal pump, this entire process happens in one continuous pass through a single impeller — here’s what that looks like inside your pump:
- Fluid enters the impeller eye: Fluid is drawn into the center of the single rotating impeller through the suction inlet.
- Centrifugal force takes over: As the impeller spins — typically driven by an electric motor — its curved vanes fling fluid outward toward the impeller’s edge, accelerating it and building velocity in this single stage.
- The volute casing converts velocity into pressure: The surrounding volute casing is shaped to gradually widen, slowing the fluid down and converting that velocity into usable pressure as it moves toward the discharge outlet.
- Fluid exits under pressure: The pressurized fluid leaves through the discharge port and continues into your piping system — all delivered from a single pass, without additional stages.
Because a single stage centrifugal pump only passes fluid through one impeller, its maximum achievable pressure is naturally capped by what a single stage can generate. That’s the exact limitation that leads some applications toward a multistage design instead, which repeats this same process across several impellers in series to reach higher pressure.
Single Stage vs. Other Centrifugal Pump Types at a Glance
A single stage centrifugal pump is one of several types of centrifugal pump your business might consider — the right choice depends on how your pressure, flow, and installation needs compare to a single stage baseline:
| Pump Type | How It Compares to Single Stage | Choose This When |
|---|---|---|
| Single stage centrifugal pump | Baseline — one impeller, one pressure-building pass | Your application needs high flow at moderate pressure |
| Multistage centrifugal pump | Multiple impellers in series — significantly higher pressure than single stage | Single stage pressure output isn’t enough for your system |
| Horizontal single stage pump | Same single stage principle, shaft mounted horizontally | You want easier maintenance access on a single stage unit |
| Vertical single stage pump | Same single stage principle, shaft mounted vertically | Floor space is limited or the unit needs a smaller footprint |
In other words, most of the “other types” your business will encounter are really variations on the same single stage design — the one exception being multistage, which changes the fundamental pressure-building mechanism itself.
Applications of Single Stage Centrifugal Pump
Thanks to its simplicity and reliability, a single stage centrifugal pump shows up across a wide range of industries. Common applications of single stage centrifugal pump systems include:
- Water supply and municipal systems: General water transfer, booster stations, and irrigation networks
- HVAC systems: Circulating water through commercial heating and cooling loops
- Light industrial processing: Moving process fluids that don’t require high pressure
- Food and beverage production: Stainless steel single stage pumps for sanitary fluid transfer
- Wastewater and drainage: Moving high volumes of fluid at moderate pressure
- Fire protection systems: Supporting water flow in sprinkler and hydrant networks — similar to the principles behind how a diesel fire pump works, though fire pumps are engineered to a different standard
If your business needs a reliable, sanitary option for these applications, CDUN Pump’s ZS series horizontal single stage centrifugal pump is built in stainless steel for exactly this kind of demand.
Single Stage vs. Multistage Centrifugal Pump: Key Differences
Since multistage is the one pump type that fundamentally changes how pressure is built, it deserves a closer, direct comparison against your single stage baseline:
| Factor | Single Stage Pump | Multistage Pump |
|---|---|---|
| Number of impellers | One | Two or more, arranged in series |
| Pressure output | Lower to moderate | High |
| Flow rate | Typically higher | Typically lower |
| Design complexity | Simple, fewer moving parts | More complex, more precision components |
| Maintenance | Easier and less costly | More involved due to multiple stages |
When Multistage Outperforms Your Single Stage Pump
While a single stage centrifugal pump covers most moderate-pressure needs, there are specific situations where the advantages of multistage centrifugal pump over single stage designs make it the better choice for your business:
- High-rise water supply: Delivering adequate pressure to upper floors of tall buildings
- Boiler feed applications: Where very high discharge pressure is required
- Deep well water extraction: Lifting water from significant depths
- High-pressure industrial processes: Reverse osmosis, high-pressure washing, and similar systems
If your project falls into one of these categories, CDUN Pump’s CDLF series multistage vertical centrifugal pump is engineered specifically to deliver that higher pressure output reliably — but for everything short of these cases, a single stage pump remains your simpler, more economical option.
Choosing the Right Pump for Your Business
The right choice ultimately comes down to your required flow rate, pressure, fluid type, and installation constraints. If you’re not sure which configuration fits your project, CDUN Pump’s engineering team can help you match the correct pump to your exact operating conditions — before you commit to equipment.
Get Pump Selection Advice from CDUN Pump
Quick Tool: Single Stage or Multistage — Which Fits Your Application?
Choose single stage if: you need high flow at low-to-moderate pressure, a simpler system to maintain, and a lower upfront cost.
Choose multistage if: your application needs high discharge pressure, such as high-rise buildings, deep wells, or boiler feed systems.
Still unsure? Contact CDUN Pump’s team with your flow and pressure requirements for a tailored recommendation.
FAQs
What is a single stage centrifugal pump used for?
It’s used to move fluid — water, process liquids, or wastewater — where moderate pressure and high flow are needed, such as HVAC systems, water supply, and general industrial transfer.
How does a centrifugal pump work in simple terms?
A rotating impeller flings fluid outward using centrifugal force, and the surrounding casing converts that velocity into pressure as the fluid moves toward the discharge outlet.
What’s the difference between single stage and multistage centrifugal pumps?
A single stage pump uses one impeller and delivers moderate pressure, while a multistage pump uses multiple impellers in series to achieve significantly higher pressure.
When should my business choose a multistage pump instead?
Choose multistage when your application requires high discharge pressure — such as high-rise water supply, deep well extraction, or boiler feed systems — that a single stage design can’t achieve.
Are single stage centrifugal pumps more affordable than multistage pumps?
Generally, yes. Fewer components and simpler design mean lower upfront cost and lower maintenance costs over the pump’s operating life.
What types of centrifugal pump are available besides single stage?
Common types include multistage, horizontal, and vertical centrifugal pumps — with horizontal and vertical single stage designs sharing the same core single stage principle, just in different mounting orientations.
Can a single stage centrifugal pump handle industrial fluids beyond water?
Yes, depending on materials of construction. Stainless steel single stage pumps are commonly used for sanitary, corrosive, or process fluid applications.
How do I know what flow rate and pressure my business needs?
This depends on your system’s pipe layout, elevation, and application demand. A hydraulic calculation or consultation with a pump engineer will determine the right specification.
Is a single stage centrifugal pump suitable for fire protection systems?
Fire pump systems have their own dedicated design standards and are typically purpose-built rather than general-purpose single stage pumps — though they rely on the same core centrifugal working principle.
Does CDUN Pump manufacture both single stage and multistage centrifugal pumps?
Yes. CDUN Pump manufactures both single stage and multistage centrifugal pump series, including stainless steel options, so your business can select the configuration that matches your application.
