Continuous flow oxygen system

A system of aviation breathing oxygen in which a metered amount of oxygen flows continuously into the mask. A rebreather-type mask is used with a continuous-flow system. The simplest form of continuous-flow oxygen systems regulates the flow by a calibrated orifice in the outlet to the mask, but most systems use either a manual or automatic regulator to vary the pressure across the orifice proportional to the altitude being flown.