How is the cylinder closed after use?

The cylinder is closed after use by pressing the hand wheel inwards. This mechanism is designed to ensure that the valve is securely shut, preventing any accidental leakage of air when the SCBA is not in use. Pressing the hand wheel inwards activates the closure mechanism, creating a tight seal that is critical for maintaining the integrity of the breathable air supply.

This process is key to ensuring safety, as it protects users from potential exposure to contaminants in the environment while the apparatus is stored. Proper closure of the cylinder also helps in preserving the air pressure and prolonging the service life of the cylinder. Other options involve actions that either don’t directly relate to closing the cylinder or could lead to improper closure of the valve.