Totally off topic, but :
The EC will definately do it, he just had never seen the compressed air lines done in other than pvc if done at all he is strictly residential.
My understanding is that PVC pipe is _not_ recommended for compressed gas service. OSHA document here
http://www.osha.gov/dts/hib/hib_data/hib19880520.html Please remember that a pipe filled with compressed gas at a given pressure stores far more energy than a pipe filled with liquid at the same pressure. In the event of a pipe failure that energy goes into physically moving pieces of the pipe around.
-Jon