Equipment for a piping system - Problem

[E-Key]

Hi,
It seems Revit has some limitations in defining piping system. General idea for system is we collect a number of client elements (they for a system members) and then we assign an equipment for it. And here is a problem.

You can see a typical schematic drawings here:
2012-07-10_0947.png
On the drawing you can see elements (evaporators) what suppose to be equipment (in Revit terms) for the system. But Revit doesn't support multiple elements to be assigned for system equipment.

Another problem is that evaporators are arranged in a group. To arrange flows for parallel elements properly we have to use a family with connectors having the Flow Configuration property equal to "System" and flow is driven by Flow Factor parameter.
2012-07-10_101840.jpg
The problem is that an engineer knows the flow for every element and wants to assign the value directly. This requirement need family's connectors parameter Flow Configuration to be set to "Preset". In this scenario we can't assign an evaporator as equipment and also we can get Revit warning that it can't calculate the system because there is no elements in the system with Flow Configuration equal to "Calculated".


I would be very appreciated for any suggestion.

EK