Save Money & Maximize Performance with a Pump Performance Curve

Do you know how to set the speed of a pump correctly using a performance curve? Doing so can yield big fuel (and money) savings, and will maximize pump performance.

The horizontal (bottom) scale of the curve is the capacity in U.S. Gallons per Minute (GPM). The vertical (left) scale is the amount of pressure or resistance the pump is working against, expressed in PSI and feet of head (TDH). Normally, the “feet” scale is used.

Now look at the curved lines on the graph. They predict how the pump will perform at various engine speeds (1900, 1700 & 1500 RPM). The graph also shows how pump performance is affected by the amount of static suction lift (25’, 20’, 15’, and so on).

Here’s how it works. Let’s assume you want to pump 1000 GPM and your water source is 25’ below the pump (25’ static suction lift). Find the 1000 GPM point on the bottom scale and follow it up until it intersects the 25’ static lift line, then draw a straight line to the left scale. This demonstrates that the pump will achieve 1000 GPM at 95’ of head with a static suction of 25’ running the pump at 1700 RPM. Setting the RPM higher wastes fuel; setting the RPM lower will not achieve the desired performance.

This is a simple explanation of a complex topic. Call our experts for advice on how to properly calibrate your pumping system while minimizing cost.