So, do I, or do I not, use PVC pipe to plumb my compressed air?
PVC pipe is poly-vinyl chloride. If you look at the manufacturers markings on the pipe, it will often say that the pipe is pressure rated for 140 PSI or 150 PSI, somewhere in that range, depending on the manufacturer and the pipe diameter.
Does the temperature ever get to 90 degrees, maybe 100 degrees, or even hotter where you are? If it does, then the pressure rating of your PVC pipe just dropped dramatically, and all of a sudden, a 120 PSI air pressure inside when the outside air is cool, can now rupture the pipe as the pressure rating for that PVC pipe has dropped below the danger level as the temperature where it was installed rose!
I know that before you use any PVC material to plumb any pressure of compressed air, you do want to contact the manufacturer and get them to confirm, in writing (emails are wonderful), that their material is suitable for use in a compressed air plumbing application.
In order of materials that I would choose for plumbing my compressed air, and if price were no object, I would pick copper pipe as the best route for problem free compressed air plumbing.
Next I would use rubber air hose (see the hose page for info), and if I did not need a high flow of air, my next choice would be polyethylene tube.
Yes, you lose air when the tube pops, but there is no real safety issue with using P.E. tube that is rated for industrial air pressures.
Next, and way down on the list, but sometimes necessary due to the relative low cost and the large pipe diameters available for air mains, is black pipe for air lines. It has drawbacks including difficult installation and the generation of rust and debris inside the pipe as time goes on, but black pipe has its proponents too.
All of these air-line plumbing products are discussed at length on the various pages of this website.