The recent ability to swap pressure pipe networks is a very welcome addition to C3D, however, this needs to be used in conjunction with the ability to merge pressure networks. It should be possible to model networks independent of each other, and then be merged into one larger network, instead of modelling the entire network from scratch. This would allow multiple team members to design pressure networks, and combine them on a final design.
An example would be a new suburban area consisting of multiple housing developments, and each development is given to a separate designer for modelling. Once all subdevelopments have been modelled, they are handed over to a senior modeller/Engineer, for merging and further analysis.