I've got a project where the irrigation main line infrastructure has already been installed. It's a complicated site, involving several wells and booster pump stations, as well as at least 6 different types/sizes of main line. I've set up my drawing with a separate ML pipe class for each type/size already in the ground, as well as for additional main to be installed by the LS contractor. When I size the system, the pipe class I've drawn for the already-installed 4" Sch 40 main, for example, will change to the 2" SDR 21 main if the volume isn't high enough. I've set up each class with only the size installed available. If I'm sending too much volume through a given class, I'll get the message saying I need bigger pipe, so I adjust my flow zones, etc. If too low, it just goes ahead and switches classes.

Is there any way to make my choices "stick?"

And a related note: can I add, or can we get, more ML pipe class choices? In this case, 6 is not enough.

Thanks!