Gas fill process and inflator weld design simplification

A method for filling an enclosure with an ignitable mixture of gases, the enclosure having an outer wall comprising an exterior surface, an interior surface, and a fill aperture extending there through, the method comprising:

• delivering a predetermined amount of pressurized combustible gas into the enclosure through the fill aperture;
• delivering a first predetermined amount of pressurized inert gas into the enclosure through the fill aperture at a first pressurization rate, the first pressurization rate allowing the first predetermined amount of pressurized inert gas to mix with the predetermined amount of pressurized combustible gas to form an ignitable mixture within the enclosure, the first pressurization rate resulted a first temperature;
• delivering a second predetermined amount of pressurized inert gas into the enclosure through the fill aperture at a second pressurization rate, the second pressurization rate being lower than the first pressurization rate, the second pressurization rate allowing stratification to form within the enclosure between a layer of the ignitable mixture at the first temperature and a layer of the second predetermined amount of pressurized inert gas at a second temperature, wherein the second pressurization rate resulted the second temperature, and the second temperature being lower than the first temperature, wherein the stratification between the ignitable mixture and the second predetermined amount of pressurized gas is the result of a thermal gradient, the layer of the second predetermined amount of pressurized inert gas being disposed between the layer of the ignitable mixture and the fill aperture;
• and welding a sealing member to the outer wall of the enclosure by a welding process to form a weld operable to seal the fill aperture and to permit the enclosure to store pressurized gas therein.