Which statement best describes the function of the reserve supply in a medical gas system?

• A. It is a backup for testing only
• B. It is used to vent gas during maintenance
• C. It automatically engages when primary and secondary fail
• D. It serves as a decorative label

Answer: (C)

Reserve supply serves as a ready back-up that keeps medical gas flowing even when the normal sources aren’t available. It’s tied into the distribution network with automatic changeover valves and pressure sensors, so if the primary source fails—and if a secondary source is also unavailable—the reserve automatically engages to maintain the necessary pressure and flow to outlets and patients. This automatic handover is crucial for patient safety, preventing interruptions in gases like oxygen or air. It isn’t used for testing, it isn’t a venting solution during maintenance, and it isn’t decorative—the reserve’s purpose is to ensure continuous, reliable gas delivery when other sources fail.