Bob La Londe wrote:

Wadda ya think?

P.S. I have seen other shops use PVC also, and they said they never had
any problems.

I've been using PVC, schedule 40, for a decade with no problems. I do
however, limit line pressure to 80 psi. Having said that, I am
considering replumbing everything with 3/8 nylon tubing. I'm not going
to the expense of iron or copper unless I manage to score enough to do
the job at scrap prices. Reasons for replumbing is several joints have
developed minor air leaks, as well as the ease of adding lines. My
consumption is not great enough to worry about flow restrictions.
And I happen to have a 100' roll I scored on ebay dirt cheap...

When I finally get into a permanent shop that I own, I'll use copper.

Jon