My team has spent a great deal of time reading the rules over and over and came to the conclusion that using a different tank for air storage would in fact be legal. The specifications are well over that of FIRST’s regulations specified in the rules and it is a COTS item.
Is this right or are we pushing the rules a bit?
The GDC did say that there is not limit to the amount of air stored this year. As long as it’s a COTS part, it’s legal, according to rule R66, updated in Team Update #2.
Team Update #2 makes doesn’t give a limit to the number of pneumatic storage tanks a team can use. This makes it sound like teams can use an unlimited number of storage tanks on the hostbot. Is this true?
GDC: Correct, there is no explicit limit on volume of stored air permitted on the ROBOT
Thank you! For some reason my team hasn’t printed out the revisions yet … we should probably do that 
R66…
K. Pneumatic storage tanks.
There is no limit on size or volume as long as all other rules are satisfied. If you are using an unknown tank, be ready to show a specification sheet, listing working and burst pressures for your pneumatic components.