Simulate bypass flow through a pump that is turned off

  Product(s): WaterGEMS, WaterCAD
  Version(s): 08.11.XX.XX, 10.XX.XX.XX
  Area: Modeling


When modeling a pump in WaterGEMS, is there a way to have the pump turn off, but still allow flow through the pump.

Problem ID#: 84859


When the pump is off, the pump is assumed to be closed and no flow is allowed through the pump in either direction. If you want to simulate a case where flow will still move through the pump, you can try setting up
a bypass pipe around the pump.

Either place a check valve on the pipe such that it is closed when the pump is on, or add controls

For the controls approach - when the pump is off, the bypass pipe can have a status of Open. If the pump is on, the status of the pipe can be Closed (though pumped flow may be large enough in some cases where the extra flow through the bypass will not impact the model results). The status changes are made with the use of controls. For setting up the controls see this wiki for V8i versions of Select Series 5 and lower and see this wiki for V8i and CONNECT edition versions or higher.

An example of the controls for this would be:

IF PMP-1 Status = On  THEN P-6 Pipe Status = Closed

IF PMP-1 Status = Off  THEN P-6 Pipe Status = Open

In another example, you could combine the action of opening and closing the pipes with the same controls that turn the pumps on and off (composite action).