I'm late getting in on this but PVC is something that you can get away with but it's not recommended.I work for Ingersoll Rand and they absolutely consider it a safety issue,If you must do it on a budget and you want to keep it easy then use Synflex.It's available in several sizes and uses push in connectors.We use it on the interior of all recip and rotary compressors up to 200 psi and never have any problems as long as it is seated well during assembly.And as far as moisture,always run your drops through a T fitting and stub down 6 or so inches to a small ball valve so as to drain your drops.We use modular aluminum so you can drill and tap a drop anywhere in the system but it is pricey.BTW It is installed level and plumb for appearance and never sloped back to the tank.You don't want moisture in your tank either.Ball valve the output of the compressor so its not loaded all the time and for maintenance also.Install a blow down valve to dump the system at power off and a timer based automatic drain valve on your tank to control moisture build up in the tank.If I can help anybody out with questions PM me.
Greg