PADI Divemaster Certification Practice Exam

What device prevents an over-pressurized cylinder from exploding?

1. Regulator

2. Relief valve

3. Burst disk

4. Pressure gauge

The correct answer is: Burst disk

The burst disk is a safety device used in scuba cylinders to prevent over-pressurization. It is designed to rupture at a specific pressure, which allows gas to escape safely from the cylinder instead of causing a potentially explosive failure. When the pressure inside the cylinder exceeds the designated limit, the burst disk will break, relieving the excess pressure and thereby protecting the integrity of the cylinder. Understanding the function of a burst disk is crucial for diver safety as it serves as a last line of defense against potentially catastrophic failure due to over-pressurization. This is particularly important in scenarios where the pressure in the cylinder could unexpectedly rise, such as during extreme temperature changes or when the cylinder is improperly filled. While regulators, relief valves, and pressure gauges play important roles in managing air supply and monitoring pressure within a diving system, they do not specifically function as a point of failure like the burst disk does. Regulators are used to reduce the high pressure of the air from the cylinder to a breathable level, relief valves allow gas to escape from the system under certain conditions, and pressure gauges simply indicate how much air is left in the cylinder. None of these options provide the same preventative measure against an explosion due to over-pressurization as the burst disk does