Can I plot Composite Pump Curves?

Yes. Composite pump capacity curves can be developed for pumps installed in Series or Parallel. This provides a powerful method of communicating your system design and pump performance data.

Lets consider an example where we have four pumps in parallel with only three of the pumps operating. As we can see below, pump node 12 has been set to "Off or Closed" from the Input tab of the Data Palette and as such, there is no flow through that section of the system.

 

To create your composite chart, select:

Tools | Composite Chart Setup.

This opens the "Composite Chart Setup" form as shown below. Ensure you have selected the second tab titled "Parallel and Series Pumping".

We can see above that even though the model has four pumps, we can only develop the composite chart for three of the pumps as the fourth pump (node 12) is turned off. 

Select the PLOT button to create the chart. The chart below shows the composite curve data for pump nodes 10 and 11. The lighter colored dashed lines represent the capacity of the individual pumps whereas the solid continuous line represents the composite curve. 

The image below is from a different example of pumps in parallel and offers some further supporting information on this topic. Point 1 shown below is the duty-point if only one pump were operating and Point 2 is the duty-point when both pumps are operating.