A multistage pump emerges as a reliable and versatile solution across numerous industrial and commercial applications requiring high-pressure fluid transportation. Boasting enhanced efficiency and robustness, these pumps find their ideal utility in scenarios where a single-stage pump may fall short. The key advantage of employing multistage pumps lies in their ability to generate significantly higher pressures by pumping the fluid through multiple stages. This approach results in each stage increasing the overall pressure.
This guide will answer the following questions:
Multistage pumps come into play in scenarios such as water supply for high-rise buildings, oil and gas processing, water treatment plants, irrigation systems, and desalination processes. Additionally, their proficiency in dealing with boiler feedwater challenges in power plants underscores their importance in the energy sector. The modular design of these pumps also enables seamless customization, facilitating a perfect match for specific project requirements. Moreover, with advancements in technology, multistage pumps have seen improvements in energy efficiency and maintenance ease, further solidifying their position as a cost-effective and eco-friendly choice.
How does a multistage centrifugal pump work?
A multistage pump operates by utilizing multiple impellers arranged in series within the pump casing. Each impeller is responsible for increasing the pressure of the fluid as it passes through. As the fluid enters the pump, it is drawn into the first impeller, where it gains some pressure. The partially pressurized fluid then moves to the next impeller, and the process is repeated through all the impellers, each one contributing to a gradual increase in pressure.
Examples of Multistage Pumps
To conduct a peripheral pump service you will need to go through the following steps:
Vertical Multistage Centrifugal Pump: This type of multistage pump consists of several impellers stacked in a vertical arrangement with the motor mounted above the pump. Vertical multistage pumps are commonly used in water supply systems, building services, irrigation, and industrial applications where high pressures are required in a compact design and are particularly suited for installations where space is limited.
Horizontal Multistage Centrifugal Pump: Similar to their vertical counterpart, the horizontal multistage pump comprises multiple impellers, but they are arranged in a horizontal configuration. Large horizontal multistage pumps can exceed the pressures and flow rates of their vertical counterparts and may find use in industrial processes, boiler feedwater systems, pressure boosting, and water circulation in cooling towers.
Borehole Multistage Pump: Borehole multistage pumps are specifically engineered for extracting water from deep boreholes or wells. The multistage configuration of these pumps enables them to lift water from considerable depths to the surface. Borehole pumps are commonly used in domestic, agricultural, and industrial settings, where access to groundwater is essential for various applications such as irrigation, livestock watering, and residential water supply.

The construction of a multistage pump
A multistage pump is comprised of several key components that work together to facilitate the efficient transportation of fluids at high pressures. The main components of a multistage pump include:
Pump Casing: The outer shell that encloses all the internal components of the pump, providing structural support and directing the flow of fluid.
Impellers: Multiple impellers, also known as stages, are mounted on a common shaft inside the pump casing. Each impeller increases the pressure as the fluid moves through the pump.
Shaft: The central rotating component that connects and drives all the impellers in the pump.
Mechanical Seals or Packing: These components seal the casing where the shaft enters, preventing leakage of fluid from the pump along the shaft.
Diffusers or Guide Vanes: Positioned between the impellers, diffusers or guide vanes direct the fluid flow from one stage to the next, optimizing the energy transfer and pressure buildup in each stage.
Suction and Discharge Ports: These are the entry and exit points for the fluid into and out of the pump. The suction port draws fluid into the pump, while the discharge port releases the pressurized fluid to the system or application.
Coupling and Motor: In motor-driven multistage pumps, a coupling connects the pump’s shaft to the electric motor, enabling the transfer of rotational energy from the motor to the pump.
Casing Wear Rings: These rings, often made of abrasion-resistant materials, protect the pump casing and impellers from wear caused by the movement of the fluid.
O-rings and Gaskets: These components provide sealing between various pump parts, preventing leaks and ensuring the pump’s efficiency and safety.
Pressure Relief Valve: Some multistage pumps may include a pressure relief valve to protect the pump and system from excessive pressure buildup, particularly in scenarios of sudden pressure changes or blockages.
At AQS Liquid Transfer, we take pride in offering a comprehensive range of high-quality pumping solutions, specializing in borehole pumps and vertical multistage pumps. As a trusted supplier, we are committed to delivering cutting-edge technology and exceptional performance. With AQS Liquid Transfer, you can be assured of obtaining top-tier pumps tailored to meet your specific needs, ensuring consistent and dependable fluid transportation solutions.
Do you still have questions? Give our AQS Liquid Transfer team a call on +27 12 548 7204 or fill out our enquiry form, our friendly team will get back to you with first-hand expertise on how to select a borehole pump for your needs.