FIRST air cannon robots PVC??

[KenWittlief]

the reason its only rated for water is pressurized water does not store up energy. Pressurized air does. If a water pipe breaks then water sprays out. If a pressurized plastic air tank breaks, then fragments of plastic spray the room, along with the concussion of the released air.

FIRST has been very restrictive concerning the use of custom / plastic pressure tanks on the robots: they are strictly forbidden. I gotta believe a lot of thought went into that decision. Putting stuff on a FIRST robot after the season ends that violates rules that exist for safety makes me a little worried (even if other teams have already done so).

Id recommend one of those portable tire air tanks you can get at Walmart for $60 or so. The ones you fill up at a gas station with compressed air. They are tested well above their rated pressure (rated at 120psi?), and they are steel, so if you drop one the seams wont burst open.