Yeah, I know you are supposed to use black iron. I did that at my other shop. It worked well, but I never got all the leaks out. Plus- it is a PAIN to rearrange.

I am in a situation where I want to run some permanent air lines that I know will be changing at some point in the future. My barn/workshop will continue to be a work in progress for years to come, and machines and work areas will evolve.

I have some left over 1/2" pex and the (expensive) crimpers. I've had very good luck with this stuff with regard to no leaks. I once re-plumbed a house with it- no leaks at all- and this was the first time I ever used it.

The tubing itself is rated plenty high enough in terms of pressure. I know that PVC pipe is a bad idea (although plenty of folks do it). I can't see how pex would present any sort of danger, as it is not at all brittle.

It is very easy to run and snake around where you need it. I figure I'd still do the condensation drain drops like they suggest for iron piping. Or maybe I'd do a hybrid approach- iron for the main runs and pex for branches to specific areas.

I just wonder if anybody out there has tried it for compressed air.

Anybody tried this?