Run Out Capacity


This is the maximum discharge and lowest head anticipated in the application.

If you do not know this number you could experience several problems that would include:

  • The net positive suction head required (NPSHR) might be too low and the pump will cavitate.
  • This information is needed to prevent motor overload.
  • If you do not have a low enough L3/D4 you could experience shaft deflection and possible breakage problems.

This number becomes important if you are running two pumps in parallel and you shut one of them off, causing the remaining pump to intersect the system curve  further out on the capacity side.

You should be able to get the run out capacity number from the pump manufacturer, or distributor.