IfcSystem information related to pipes - IFC4 from Revit

Hi, everyone!

I work with building project management and my workflows consist mainly of IFC exports from Revit and code/clash checking on Solibri.

I’ve noticed recently that my IFC4 models from Revit don’t show the value of “ifcSystem” for pipes; however, if I export the same model in IFC2x3 this information is shown.

I’m not sure if this is a problem of Solibri, Revit, or an IFC-related one. Just so you know, on Revit the pipes are classified as “ifcPipeSegment”. I’ve checked the schema specifications and apparently the “ifcSystem” entity cannot be attached to the “PipeSegment” one, but I’m not completely sure of it.

What could be the issue here? Does anyone know how to manipulate IFC classifications and properties on Revit for this to work?

Can you please elaborate on that? I was under the impression that IfcSystem (or IfcDistributionSystem for pipes to be precise) like IfcGroup it is, is capable of holding any IfcProduct using IfcRelAssignsToGroup.

The grouping relationship to one or several instances of IfcProduct (the system members) is handled by IfcRelAssignsToGroup.

I confess I still have a bit of trouble with looking at the schemas, so I may be wrong. Now that you explain it this way, it makes more sense.

However, considering it is possible to assign IfcDistributionSystem to the IfcPipeSegment, I still don’t understand why this value appears on IFC2x3 and not on IFC4.