The pump curve is the most important document when selecting a pump. Learn how to interpret it and match it to your system.
A pump curve (also called a performance curve or H-Q curve) graphically shows the relationship between flow rate (Q) and head (H) for a specific pump.
Reading the Curve:
Best Efficiency Point (BEP):
The BEP is the flow rate at which the pump operates most efficiently. Operating far from BEP causes vibration, wear, and energy waste. Always select a pump whose BEP is close to your required operating point.
System Curve:
The system curve represents the head required by your piping system at various flow rates. It slopes upward. The intersection of the pump curve and system curve is the operating point.
Multiple Curves:
Manufacturers often show curves for different impeller diameters or speeds. Select the curve that gives your required operating point near the BEP.
