Gus,
You can export the Revit MEP library parts to a created by you library which will reside on the BIMserver with your other project libraries and which everyone using the project can load. You can create an .lcf of it, see the Archicad Help, it's quite easy, but you would have to redo this step everytime a new library part needs to be added to it. If you work with these consultants on a regular basis, this could be helpful for multiple projects.
However, Revit MEP parts can be quite large with the faceting of all the round pipes and it is this that can be bogging down Archicad.
Erika
Architect, Consultant
MacBook Pro Retina, 15-inch Yosemite 2.8 GHz Intel Core i7 16 GB 1600 MHz DDR3
Mac OSX 10.11.1
AC5-18
Onuma System
"Implementing Successful Building Information Modeling"