A collapsible bag for use in dispensing gaseous fluids, the collapsible bag including three collapsible enclosures. Two of the collapsible enclosures have respective fluid paths extending from internal to external of the outer enclosure. The configuration of the food quality of an inner enclosures and the integrity of the third outer enclosure and as well as the relative volume of one inner enclosure to the outer enclosures effects the dispensing mechanism of the pressure which allows transfer of the pressure without fluid interaction to another of the at inner collapsible enclosures and selective dispensing.