Pump selection may seem straightforward—just match the flow and head, right? Not quite. Ask any experienced engineer, and they’ll tell you the real world is full of overlooked details that can turn a “working” pump into a maintenance nightmare.
We sat down with our technical team to uncover the top 5 pump selection mistakes they see time and time again—plus tips to avoid them.
1. Sizing Based on Maximum Flow, Not Average
Many users select a pump based on peak flow requirements, without considering how often that flow is needed.
Why it’s a mistake:
Oversizing leads to pumps operating off the curve, reduced efficiency, excessive wear, and higher energy bills.
What to do instead:
Size your pump to operate near its Best Efficiency Point (BEP) under normal conditions, and consider VFDs or standby pumps for occasional peaks.
2. Ignoring Fluid Properties
It’s not just about water. Pumping abrasive slurries, corrosive chemicals, or viscous fluids requires special consideration.
Why it’s a mistake:
Using the wrong materials or pump type can lead to rapid wear, seal failure, or complete breakdown.
What to do instead:
Know your fluid—viscosity, temperature, pH, solids content—and select materials and pump designs accordingly (e.g. peristaltic for slurries, mag drive for corrosives).
3. Neglecting NPSH (Net Positive Suction Head)
NPSH may sound technical, but ignoring it is one of the fastest ways to destroy a pump.
Why it’s a mistake:
If NPSHa (available) is less than NPSHr (required), your pump will cavitate—causing vibration, noise, and impeller damage.
What to do instead:
Check your system’s suction conditions, elevation, and vapor pressure. Always ensure NPSHa > NPSHr with a safe margin.
4. Overlooking System Curve Changes
Pipes age. Filters clog. Valves get adjusted. System resistance isn’t static.
Why it’s a mistake:
Choosing a pump based on design conditions without allowing for real-world variability can result in poor performance or reliability issues.
What to do instead:
Build flexibility into your system. Use a system curve, not just fixed head/flow points, and allow for fouling, seasonal changes, and operating modes.
5. Forgetting About Maintenance and Accessibility
A perfect pump on paper means nothing if it’s a nightmare to maintain or access.
Why it’s a mistake:
Cramped layouts, hard-to-reach seals, or non-standard parts can cause costly downtime.
What to do instead:
Think ahead—choose pumps with accessible designs, local support, and readily available spare parts. Involve maintenance staff during selection.
The best pump isn’t just one that works—it’s one that fits your process, fluid, and operating environment for the long haul. Avoiding these common mistakes can save thousands in downtime, energy, and replacements.
Need help selecting the right pump? Our engineers are happy to assist with selection, system analysis, and troubleshooting. Get in touch today or explore our technical tools to get started.
