Problem

The option to display a system head curve does not appear for a pump when using SewerGEMS. 

How can a system head curve be generated in SewerGEMS?

Solution

If you are using the Implicit or Explicit (SWMM) numerical solver (selected in the Calculation Options), the system head curve option will not be available. System head curves can only be generated using the GVF-Convex (SewerCAD) numerical solver, available in SewerGEMS. The SewerCAD solver uses the EPANET engine for pressure hydraulics, which supports the ability to view system head curves. Select GVF-Convex as the numerical solver in the calculation options used by your current scenario (designated with the red check mark in the list of calculation options):

You will then see the option to display the system head curve when you right click on the pump:

However, it is important to note that the GVF-Convex solver has different assumptions and limitations when compared to the other solvers, which could impact the system head curve. It is recommended that you review the differences noted in the following article, as well as any User Notifications that appear when using the Validate button.

Differences between solvers: GVF-Convex vs. GVF-Rational vs. Implicit vs. Explicit (SWMM)

Furthermore, if you are sizing a pump and/or analyzing a pressure sewer system, consider using WaterGEMS or WaterCAD instead as they have a wider array of tools to help with pump selection and energy costing.

SewerGEMS for AutoCAD

In SewerGEMS for AutoCAD (AutoCAD integrated mode), the System Head Curve option will not appear in the right click context menu, since AutoCAD cannot display different right click options depending on the state of the Calculation Options. When working with System Head Curves, you'll need to be in Standalone (with the GVF-Convex solver), or use WaterGEMS/WaterCAD instead.

Known issues

As of version 10.04.00.158 the System Head Curve Manager is not available in SewerGEMS. Although you can still view system head curves when using the GVF-Convex solver, you will not be able to save them for re-use since the manager is not available. (even though it may ask you if you want to save the system head curve when you close it) The reason is because including the System Head Curve Manager in SewerGEMS could be confusing since system head curves can only be generated with the GVF-Convex solver.

If you need to save and re-use system head curves, it is advised that you use the separate SewerCAD product (if available - it is a separate license) which can open your existing models and has the System Head Curve Manager where the saved ones are stored. Reference #1173354.

See Also

How are pumps handled in each OpenFlows product?

Understanding System Head Curves in WaterGEMS, WaterCAD, and SewerCAD

Unexpected system head curve in SewerCAD or SewerGEMS