[Chris_Ely]

I found this document from Charlotte Pipe, which is one of the leading pipe manufactures. Throughout the document, there are numerous warnings about using PVC/ABS/CPVC pipe in compressed air applications.

Originally Posted by Charlotte Pipe

Testing with or use of compressed air or gas in PVC / ABS
/ CPVC pipe or fittings can result in explosive failures and
cause severe injury or death.
• NEVER test with or transport/store
compressed air or gas in PVC / ABS / CPVC
pipe or fittings.
• NEVER test PVC / ABS / CPVC pipe or
fittings with compressed air or gas, or air
over water boosters.
• ONLY use PVC / ABS / CPVC pipe or
fittings for water or approved chemicals.
• Refer to warnings in PPFA User Bulletin
4-80 and ASTM D 1785.

On page 82, they specifically mention air cannons.

Originally Posted by Charlotte Pipe

Do not use for SPUD GUNS, FLAMETHROWERS, or
COMPRESSED AIR GUNS. May result in property damage,
injury or death. Use only for fluid handling / plumbing
applications.

Everyone, please heed the manufacture's warnings. Only use materials meant for air pressure.