I think we're confusing pressure ratings for water and air. No PVC pipe is rated for air. PVC tends to shatter, so all pressure ratings are for water only. Water is ok, because it's incompressible, so a break does not cause shards of PVC to fly everywhere. Air is compressible, so energy is stored in...

I've had more luck with using metal exhaust tubing that slides over the PVC. Just use a dremel or a router to make an o-ring channel, and put an o-ring there. No leakage at all. It is a weak point, so I use 1.5" PVC inside of 2" PVC.

Check it out:

I hate to tell you guys but you *cannot* break the sound barrier on compressed air alone. Due to the laws of physics, air only travels at a certain speed. This is why the speed of sound is what it is. Even with near infinite pressure, the shock wave of pressure will only travel at the speed of sound...