Answered: Pressure Gaage in Pneumatics

Is it legal to install a pressure gauge adjacent to the air tank? The purpose of this would be to allow easy filing of the tank to the proper pressure, and to ensure that the system is free of leaks.

I’m thinking that this essentially boils down to th rule about non-functional decorations, but I cans ee how this could be considered functional even though it will not come in contact with any game elements.

No, this would not be legal. This part would definitely be considered functional, and thus not allowed as it is not part of the VEX Robotics Design System.