Using CPVC or PEX pipe for compressed air.
by Jack Waters
(Blairsville, GA, USA)
I am nearly to the point where I will have time to run pipes to carry my compressed air round to all parts of my home shop. I had planned to use rigid copper, as I know the manufacturers recommend against using PVC. I also know that PVC is not used inside houses for waterlines. However, PEX and CPVC are both considered safe to use inside houses for waterlines. Therefore, I wondered if they can be used for my compressed air system. I plan to use no pressure higher than about 150 pounds psi.
Jack, the simple answer is NO, don't do it.
Yet there are new plastics being developed that might, and I emphasize might, be suitable.
Before you take what might be a dangerous decision, I recommend that you note the pipe manufacturer's name off the pipe, email them this same question, and keep their answer on file if they say yes. In that way, you have redress should the plastic fail.
If not copper, opt for rubber/vinyl (not just PVC) hose with barbed fittings. Relative low cost, forgiving with misalignment, and won't rust.
An anonymous contributor thinks there is no problem:
What the worst that could happen? Air leak OMG someone call 911, I mean come on. If it leaks it probably gonna be at a connection. Is an air leak even at 100psi really gonna be catastrophic?
If you are in the room when a plastic pipe full of compressed air explodes and it sends shards of plastic into you and those around you... I don't know, wouldn't you consider that a worst that could happen? Ignorance is bliss. Be blissful, friend.
Can you use pvc to plumb air lines?
can you use pvc to plumb air compressors
Hi Bill. I have written about this subject extensively on this website.
To make it easier for you to find an answer to your question, I've just added a page called PVC Air Lines, which you can get to from the Site Map.
That page will be live in about 10 minutes or so. If it isn't up when you try to find it, please check back.
Charlie writes in:
I would strongly caution against using PVC to plumb your air lines.
Years ago, I worked in an auto paint shop in Orlando, FL that was plumbed with PVC. One hot summer afternoon, the line exploded for no apparent reason about 20 ft away from me and it was like a bomb going off. Everyone in the shop came running thinking a car had exploded. Nobody got hurt, thankfully, but there were shards of PVC all over the shop and all work ceased since there was now no air pressure to run tools or paint cars. Bottom line - don't use PVC for compressed air lines.
Thanks, Charley. With PVC, as the temperature rises, it's resistance to pressure drops, and as you so clearly point out, when the PVC pipe lets go, it shatters!