another option is to run PVC inside the sealed walls and metal pipe outside

when it explodes you won't lose any organs; of course you'll need to tear the wall up, but it IS a garage

OTOH - black pipe is cheap and jeez how hard is it to work with??

:d

oh yeh! :D

Kinda weird that they would say UV breaks down the PEX line. I have my water running in it right beside the air lines. That reply in post #10 of the link provided is directly from the company and they state they use it themselves for air in their own factory although (insert lawyer caution here) they cannot recommend it

My anti-virus went crazy when I clicked the link.

would it be much too ghetto to run actually airline? cost prohibitive?

how about using organic bamboo?

There are several types of plastic lines that are rated for compressed gas service. The good news is that they are easy to assemble the first time as they glue together like PVC. The bad news is repairs. The glue needs several days to set prior to use and the pipes do become brittle with age.

I have worked at several facilities that had the plastic stuff installed when originally built. At each one, we eventually replaced the lines with Copper or Stainless due to inability to do maintenance on them without incurring long down times. Typically the joints at the vallves would fail.

As noted above, in most cases the cost is less expensive but close to the cost of metal lines as well.