[Al Skierkiewicz]

I suppose I can give a small list of things that I believe do not meet this rule as written. This is by no means all inclusive but it is most definitely things that I believe are illegal and that I have seen in use at events in just the last two years.

Items that I see as violations of current and past pneumatics rules...
1. Uncontrolled shop compressors.
2. Large storage tank (5 gallon +), filled by unknown compressor and used to then fill robot storage.
3. Robot compressor on cart connected to a robot battery and run indefinitely.
4. Shop compressor stored behind a curtain and used during queuing to fill robot.
5. A jumper cable to bypass robot control of on board compressor and connect directly to robot battery.
6. Bypassing pressure switch and running compressor continuously in queue.
7. Compressor of varying type, on robot cart connected to car battery and used in addition to robot compressor with no pressure control.
8. Legal robot compressor on cart, used in addition to on board compressor.
9. A separate cRio and robot battery used to run the robot compressor.

While some of these incidents were also accompanied by resetting of the over pressure valve, most did have that protection in place and working on the robot. In some cases, observed pressure was in excess of 150 psi.
Regardless of your opinion on the subject, this rule intends that any air stored on your robot comes from one legal compressor of the type specified. That air is generated from the one legal compressor that is mounted on your robot or if none is mounted on the robot then one can be used that is off board. In all cases, the one compressor must be run using a robot battery, controlled by the robot's RoboRio by sensing the one legal pressure switch to determine system storage pressure of 120 psi max. The pneumatic system of your robot is legal to use when it is inspected and approved by the inspector (subject to reinspection at any time by Head Ref, FTA, and/or Inspector). The intact pneumatic system as inspected is the only legal means of providing air storage on your robot. If you are unsure at competition, please ask the LRI for advice.
If it helps, this rule can be interpreted as "only those items that are inspected are legal for use on your robot". All of those items listed do not meet that criteria.