Which safety device is used on an oxygen cylinder?

• A. Fusible plug
• B. Pressure safety disc
• C. Check valve
• D. Spring-loaded plug

Answer: (B)

Oxygen cylinder safety relies on a pressure-relief device that vents gas if the cylinder becomes overpressurized. The pressure safety disc is a rupture disk built into the valve assembly and is designed to rupture at a specific high pressure, releasing gas to prevent the cylinder from failing in a fire or overpressure condition. It works passively and doesn’t require any action from the user, which is crucial in emergency situations. Fusible plugs are used with other gases (like acetylene) and melt under high heat, which isn’t the standard or most reliable safety method for oxygen. A check valve prevents backflow but doesn’t relieve overpressure, and a spring-loaded plug would function more like a valve rather than the simple rupture-disc safety device used on oxygen cylinders. So, the safety disc that ruptures at a set pressure is the appropriate safety device for oxygen cylinders.