Apr 08, 2025

Different Types of Pumps and How to Select One for Your Application

By Anthony Castro

Last updated April, 2025

There are a multitude of different pumps that can be used depending on your water or wastewater application. In this article, we will review the different pump types and how to select the proper pump for your project. It is critical to select the right pump based on the application to maintain efficiency and effectiveness.

Types of Pumps

1. Centrifugal Pumps

A centrifugal pump uses rotational energy to move fluid and is commonly used in the majority of water and wastewater applications. Centrifugal pumps are formed of an impeller that rotates inside the casing with a suction and discharge nozzle to create a pressurized side to push out the fluid through the discharge nozzle. Centrifugal pumps can come in different sizes and configurations with the following features:

Single-Stage Centrifugal Pumps - Consist of one impeller rotating on a shaft within a pump casing, which is designed to produce fluid flow when driven by a motor.
Multi-Stage Centrifugal Pumps - A pump in which the fluid flows through two or more impellers fitted in series for high pressure applications.
Self-Priming Pumps - Use a built-in mechanism to remove air and gases from the suction line and are typically larger than standard models, but are less prone to cavitation.

2. Positive Displacement Pumps (Used for Thick Sludge, High Viscosity, and Precise Flow Control)

Positive Displacement Pump

A positive displacement pump is a type of pump that moves a fixed volume of fluid by repeatedly trapping it within a closed chamber and then mechanically displacing it through the system, ensuring a consistent flow rate regardless of pressure changes, often using mechanisms like gears, screws, pistons, or diaphragms to create the necessary volume variations within the pump chamber. These pumps move fluid by trapping a fixed amount and forcing it through the system but can come in a variety of different configurations, such as:

Diaphragm Pumps – Uses two diaphragms working in opposite phases that move back and forth, creating a vacuum to draw in fluid on one side and then pushing it out through the other side using pressure. These are useful for thick or abrasive liquids or chemicals.
Peristaltic (Hose) Pump – Continuously compress a flexible tube with rotating rollers, creating a vacuum that draws fluid into the tube and then pushes it along the tube to the outlet.
Rotary Lobe Pump – Uses two or more lobes rotating around parallel shafts in the pump’s body to move liquids.
Gear Pump – Repeatedly encloses a fixed volume using interlocking cogs or gears, transferring it mechanically using a cyclic pumping action.

3. Special-Purpose Pumps

Sewage Grinder Pump

Sewage Grinder Pump – Typically sits inside a buried outdoor tank that stores wastewater from a residential home or commercial building. A steel blade shreds solid waste to prevent blockage and ejects the wastewater into a public sewer system.
Chopper Pump – Uses a rotating cutting bar, positioned at the pump's suction inlet, to chop large solids into smaller pieces before they enter the pump's impeller, allowing the smaller particles to be easily pumped through the system.
Axial Flow Pump – Uses a propeller-like impeller to push fluid parallel to the pump shaft, meaning the fluid moves directly through the pump along the axis, gaining energy from the rotating blades and exiting at the other end with increased pressure.

When choosing a Pump:

Pump	Pros	Cons	Best Applications
Centrifugal Pumps	Efficient for large volumes, simple design, low maintenance	Not suitable for high-viscosity fluids, prone to cavitation	Water supply, HVAC systems, irrigation, wastewater treatment
Single-Stage Centrifugal	Simple, cost-effective, easy to maintain	Limited to low to medium pressure applications	General water transfer, cooling systems, sump pumping
Multi-Stage Centrifugal	High pressure capability, energy-efficient for high-head applications	More complex, higher initial cost, requires more maintenance	Boiler feed water, high-rise building water supply, reverse osmosis systems
Self-Priming Pumps	Can handle air in the suction line, prevents cavitation	Larger and more expensive than standard centrifugal pumps	Dewatering, sewage lift stations, marine applications
Positive Displacement Pumps	Handles high-viscosity fluids, precise flow control, works well under varying pressures	More complex design, higher maintenance, lower flow rates	Chemical dosing, food processing, oil and gas industries
Diaphragm Pumps	Can handle corrosive/abrasive fluids, self-priming	Pulsating flow, lower efficiency compared to centrifugal pumps	Chemical transfer, slurry pumping, pharmaceutical applications
Peristaltic (Hose) Pumps	Gentle on fluids, no risk of contamination, easy maintenance	Limited pressure capacity, hose wear requires frequent replacement	Medical dosing, food and beverage, wastewater treatment
Rotary Lobe Pumps	Good sanitary applications, handles solids	More expensive, requires precise tolerances	Dairy, cosmetics, biotech, beverage production
Gear Pumps	High-pressure capabilities, efficient for viscous fluids	Cannot handle solids, wear and tear on gears	Lubrication systems fuel transfer, polymer and resin handling
Special-Purpose Pumps	Designed for specific task, high efficiency for intended use	Typically expensive, not versatile for other applications	Specific industrial municipal, and commercial applications
Sewage Grinder Pump	Prevents clogging by grinding solids	Higher energy use, requires regular maintenance	Residential and commercial sewage systems
Chopper Pump	Handles large solids reduces blockage	High power consumption, more complex deign	Agriculture, food processing, wastewater treatment
Axial Flow Pump	High flow rates, efficient for low-head applications	Not effective for high-pressure needs	Flood control, drainage systems, cooling water circulation

Conclusion

Choosing the right pump depends on the specific application, fluid properties, and operational requirements. Centrifugal pumps are ideal for high-flow, low-viscosity applications, such as water distribution and wastewater treatment. Positive displacement pumps are better suited for handling thick, viscous fluids or precise flow control, making them ideal for industries like pharmaceuticals, food processing, and chemical dosing. Special-purpose pumps serve unique functions, such as sewage grinding, chopping solids, or high-flow, low-pressure movement.

By understanding the strengths and limitations of each pump type, industries can select the most efficient and cost-effective solution for their needs, ensuring smooth and reliable fluid handling across various applications.