What Is a Multistage Pump? Horizontal and Vertical Types

Supplying water to tall buildings, feeding boilers or running reverse osmosis systems all require liquid to be delivered at high pressure. A multistage pump is a type of centrifugal pump that meets this need by raising the pressure stage by stage through several impellers arranged in series on the same shaft.

This article explains how multistage pumps work, the differences between horizontal and vertical types, their advantages and their applications.

What Is a Multistage Pump?

In a single-stage centrifugal pump the liquid receives its energy from one impeller. In a multistage pump each stage consists of an impeller and a guide section (diffuser or guide vanes). Pressure rises as the liquid passes through each stage, and the total head of the pump is approximately the sum of the heads of the individual stages. Flow, however, does not increase with the number of stages; it depends on impeller size and speed.

Working Principle

1. Inlet: Liquid enters the first-stage impeller through the suction port.
2. Stage-by-stage pressure rise: Each impeller adds energy; the diffuser or guide vanes direct the liquid to the next impeller inlet while converting part of the velocity into pressure.
3. High-pressure outlet: After passing through all stages, the liquid leaves the discharge port at the required pressure.

Horizontal and Vertical Multistage Pumps

You can find models of both types in our horizontal multistage pumps and vertical multistage pumps product groups.

Advantages

• High pressure: Reaches heads that single-stage pumps cannot.
• Compact design: Small in size relative to the pressure delivered.
• Efficiency: When correctly selected, runs at high efficiency and lowers operating costs.
• Wide capacity range: Models are available for different flow and pressure requirements.
• Durability: Stainless steel impellers and a robust casing give long service life.

Applications

• Water supply and distribution
• Building and plant pressure boosting (booster sets)
• Industrial processes and washing systems
• Fire-fighting systems
• Irrigation systems
• Reverse osmosis (RO) systems
• Boiler feed systems

Construction and Materials

• Pump type: Horizontal or vertical multistage centrifugal pump.
• Number of stages: Determined by the required head (at least two).
• Casing material: Cast iron or stainless steel.
• Impeller material: Usually stainless steel.
• Flow, head, temperature and pressure limits: Vary by model; selection should be made using the pump’s performance curve.

Frequently Asked Questions

Conclusion

Multistage pumps are a compact, efficient solution for water supply, pressure boosting and process applications that require high pressure. Choosing the right number of stages and pump type ensures long, efficient service. See our vertical multistage pumps product group for available options.