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When comparing pumps, the performance curve is usually the first place we look. If two pumps deliver similar flow and pressure, it may be easy to assume they are interchangeable. Matching the curve, however, is only part of the equation. Materials of construction, for instance, must suit the liquid being pumped.  The surrounding environment, including temperature, air quality and a clean or dirty environment affect both performance and longevity.

 

Installation Footprint
The footprint is especially important when replacing an existing pump. Overall dimensions, mounting locations, and suction and discharge connections determine how easily a new pump will fit into the installation. Even small differences in the configuration can require piping modifications, changes to the mounting base, or additional space. Pumps must require enough clearance for routine maintenance, cooling, and motor removal. A pump that matches the performance but requires extensive installation changes will bring about added cost and downtime.

 

Working Pressure

The working pressure range deserves the same attention. Matching the required performance doesn’t guarantee that both pumps can handle the system’s pressure. Easily serviced or replaced motors can simplify future maintenance, while a customized replacement may increase lead times. The operating range matters, too. Two curves may overlap at the desired duty point yet operate differently within its recommended range. While one pump operates efficiently within the flow range, the other may drop in efficiency or become unbalanced due to thrust loads on the impeller at those conditions.

 

Factoring it all together
Performance curves are essential to pump selection, but they don’t tell the whole story. A proper comparison considers how each pump is built, how it performs, and how it will be serviced over time. Looking beyond a single point on the curve helps ensure the selected pump will deliver reliable operation throughout the application, rather than simply meet the initial flow and pressure requirements.

 

Need help choosing a pump? Contact WEBTROL and our team can help determine the right pump for your system.