Operating Window on the Pump Curve

This is the distance you can move off the pump’s best efficiency point (BEP) without causing excessive shaft deflection or vibration.

Most ANSI (American National Standards Institute) pumps limit you to about 10% off the best efficiency point (BEP).

The lower the L3/D4 number of your shaft, the larger the operating window.



  • On February 16, 2018