Thanks Ron for your input, OSHA rules are usually made up because someone got hurt, etc. I don't doubt that they have banned PVC for use with compressed gases. I'm just trying to understand the "why" part, that's to say why is this Sched 40 PVC good for 495 PSI of water and not safe for 135 PSI of air? Maybe the compressability of air causes a pulsating effect that the water doesn't ???
I have some buds in OSHA, I'm going to contact them.
Thanks again for helping to keep us safe!