What happens when the cylinder pressure drops to 1/3 of the supply?

When the cylinder pressure drops to 1/3 of its supply, it activates the emergency pressure side. This is a critical safety feature in self-contained breathing apparatus (SCBA) systems, designed to alert users that they are running low on air. The emergency pressure side serves as an additional supply of air, ensuring that the user can continue to breathe safely in case of an emergency situation.

This feature is particularly important for fire and rescue operations, where personnel may face hazardous environments and need to ensure a reliable air supply as they work. The activation of this emergency system helps to prevent dangerous situations arising from running out of air unexpectedly, allowing the user to focus on their tasks and exit safely from potentially life-threatening environments.