First and second stage regulator system for breathing gas

摘要

A first and second stage breathing gas regulator having a first stage redundant piston assembly with a first piston encompassing a second piston. In the eventuality the first piston fails, the second piston provides regulated gas. A safety alarm is provided when a pre-established pressure drop occurs, signalling a decrease in breathing gas by opening to provide gas to drive an audio alarm. The second stage regulator has a balanced second stage that operates with a valve lever in operative relationship to a diaphragm. A hand wheel and cammed valve permit the bypass of breathing gas around the valve of the second stage regulator when required. The outlet of the second stage regulator is provided with a trap door cover to avoid dirt and debris being introduced to the second stage regulator when a hose is not connected thereto.