I've used schedule 80 pvc in the past too, and it's still in the rafters in my basement. PVC is rated for water pressure, which is a lot different than air pressure. I've been lucky, just like you have...but I'm at the age that pushing my luck just ain't worth it no more. I wouldn't be afraid of Pex pipe for air lines, but I would use the brass fittings. Shark Bite fittings cost out the ying yang!
