August 2, 2012
Title: How to Read a Pump Curve - Basic
Disclaimer: This document is for instruction purposes only and is not intended for an actual application.
1 - All curves are broken down in a vertical and horizontal grid. The vertical grid is for Total Dynamic Head (TDH) and the horizontal grid is for volume or Gallons Per Minute (GPM). The blocks in the grid represent the incremental values for TDH in feet, vertical, and GPM in gallons, horizontal. These values are normally reflected in the upper portion of the curve, usually above the highest represented curve.
2 - If TDH and GPM are known, then, you can either find your TDH on the vertical and go horizontally across the grid till you stop at your required GPM or find your GPM and go vertical to your required TDH. If that point in the grid lands on a pump curve, then, dependent upon where you landed, you now have a pump for your application. If you did not land on a pump curve, then go to the next highest pump recommendation and see if it will meet your requirements or increase/decrease your GPM until you land on the curve and determine if this will be acceptable for your application.
3 - Ideally, you want to pick a pump on the curve sheet where your duty points, TDH and GPM, are toward the middle right of the curve line. This will be where the pump is the most efficient. If your duty point lands to the extreme right or left on the curve, then, that particular pump will be a “bad” pick because you will have the potential of overloading the pump motor and over a period of time, burn it up.
4 - If your duty points, TDH and GPM, do not land on a good location with any of the curves, then, you will want to look at curves for the next highest or lowest rated pump.
