The other issue is that no manufacturer (to my knowledge) has studied the affects of the oil in the compressed air on the PEX tubing.
Why take the risk with your safety to save a few dollars?
RapidAir is specially formulated to withstand the temperature and pressure swings of compressed air. It won’t blow up in your face like PVC does. If you want to use a flexible pipe system then use RapidAir or an equivalent. Save your eyesight and other bodily parts from harm- or someone else’s body parts if you don’t care about your own.
As an alternative, go to a compressed air distributor and buy aluminum piping. It is every bit as good as copper, uses compression fittings that some manufactures warranty to be leak-free for 10-years, and is very easy to install versus hanging and threading (relatively) heavy iron pipe, or sweating copper. The aluminum doesn’t corrode, either.
I can buy a 16-foot stick of Infiniti 20 mm (~3/4- inch) aluminum pipe for $33. A metal 90-degree elbow union costs $19, and a metal equal tee costs $27. (RapidAir fittings are nylon and are about half the cost.) Yes, the fittings are expensive, but again they don’t leak, install using an adjustable wrench, and can be reused if you need to make a change. The average garage install won’t cost that much, and let’s not forget the time saved by not soldering or threading pipe or repairing leaks.
Do a search for these brands for more information:
Infiniti (industrial, uses all metal fittings)
RapidAir FastPipe (consumer grade)
Transair (industrial, uses plastic fittings)
Airnet (industrial, plastic fittings)
DP instead
