A gas supply warning and communication system to generate and communicate alarm signals indicating gas pressure and gas flow malfunctions in a pressurized gas system, and to open a reserve gas reservoir in the event of certain types of malfunction. The system stores, transmits, and makes available for download, gas pressure, gas flow, and oxygen concentration data, and information regarding the status of the system. The system also accepts commands for modification of system function from users of remote devices. A software product encoding methods for operating the gas supply warning and communication system. A motorized reservoir changing device including a universal valve coupler, and methods for operating a reservoir valve with the reservoir changing device. A gripper tube for secure connection of gas lines linking components of a pressurized gas system.