Abstract: An in-home stationary oxygen delivery system provides oxygen to patients by way of a standard oxygen concentration process and delivers the oxygen to a patient through industry standard ports such as the CGA-870 port. A unique fill nozzle is used to fill the ambulatory cylinders from the in-home oxygen concentration. A valve for the ambulatory cylinder provides a unique fill port for mating with the nozzle of the stationary unit while at the same time allowing the oxygen in the charged cylinder to be dispensed through a CGA-870 standard industry port. The valve utilizes check valves to prevent filling of the cylinders through the CGA-870 port.