Pre-charging pneumatic air tank

[mikets]

At our last district competition, we routinely pre-charged the air tank while queuing for the match. We were plugging the compressor power directly to a battery with a switch. Once the pressure reaches a certain PSI, we turn off the switch and plug the compressor back to the system.The field staff told us not to do that. If we need to pre-charge the air tank, we must do so via the cRIO. I can see the reason behind it. I can see if the person doing that got distracted and not paying attention to the pressure gauge, that could be dangerous. However, I am thinking we could build a pneumatic charging station by putting together a battery, a master ON/OFF switch, a pressure limiting switch, a spike relay and a compressor such as in this diagram (sorry about the crude diagram, I am at a computer with only mspaint).

Is this allowed?