Sorry, but Sched. 40 PVC IS NOT NOW OR HAS EVER BEEN RATED FOR GASEOUS
USAGE... Read the friggin spec before you spout off that it is
acceptable for usage in air service. PVC an CPVC are rated for
INCOMPRESSIBLE FLUID SERVICE ONLY. The pressure value thatis printed
on the side fo the pipe that you are lookig at is ONLY FOR WATER. Take
the time to use the pressure burst calculations for gaseous usage and
plug in the allowable stress for PVC and it will tell you differently.
If you run the calculations you will find that 1/2" PVC can SAFELY
carry something around 4...YES FOUR PSI.

There are plastic pipe materials that are rated for gaseous usage, but
PVC and CPVC are not and anyone that uses them for air service has
basically installed a hair triggered bomb in their shop. When it goes,
and it's not a question of will it go, but when it goes, it will do so
violently and with all sorts of shrapnel that can do significant
damage.

Do yourself a favor and Google the subject before you decide to plant a
bomb in your shop. If you go ahead and use PVC, tell us where your shop
is so that we can aviod coming anywhere close to it.

Craig C.