I am currently working on an existing pipe network and I have come across a few sections of pipe that are CMPA (Corrugated Metal Pipe Arch). I had a similar issue when I needed to use an RCPA and was fortunate enough to receive a link from an Autodesk Support member that gave me the files to place into my Parts List. Now I have to apply CMPA to a section and this is not in the Parts List either.
Autodesk should really look into adding these common pipes to the software as my pipe network may be useless if I can't apply the correct pipes needed to bring into my Storm & Sanitary Analysis. I even thought of using the concrete arch pipe and jacking up the parameters and playing with the mannings coefficient and other settings, but that is a far stretch.............Any feedback will greatly be appreciated.
I would look to the manufacture of the metal arch for the autoCAD products necessary to get his products to market via your design.
i am working on an existing network, but I can use his in the proposed i guess if needed and see if that would work. thanks!