US Patent 7803218 Drain valve assembly

An on-board oxygen generating system is provided, which includes an air supply duct, a breathing gas duct, and an oxygen generator fluidly coupled between the air supply duct and the breathing gas duct. The oxygen generator is configured to enrich the oxygen content of air flowing from the air supply duct to the breathing gas duct. A drain valve assembly is fluidly coupled to the air supply duct and configured to move between: (i) an open position wherein condensation may drain from the air supply duct, and (ii) a closed position.