Advanced Composites and Alternate Power Sources, Respectively

Compressed Natural Gas is the leading alternative automative fuel candidate. However, current cylinders used for on-board CNG storage are expensive, overweight, and have limited capacity. The Flex Tube program develops technology that significantly reduces CNG fuel storage system cost, weight, complexity, and installation efforts. Unlike conventional cylinders, Flex Tube is a composite-overbraided tubular pressure vessel that conforms to the shape of a vehicle's chassis or body. Its carbon/glass braided reinforcement is impregnated with a tough elastomeric resin over a thermo-plastic liner. The tube is terminated with metallic end fittings with valve ports. The extruded liner and overbraided reinforcement promise low manufacturing costs. Futhermore, Flex Tube provides sufficient capacity in a single continuous pressure vessel, eliminating valves and manifold hardware required by conventional multi-cylinder storage systems. By flexing and conforming to the available vehicle space, CNG capacity is maximized with minimum impact on the vehicle. The Flex Tube concept was demonstrated in a Navy submarine application. This Phase I effort further develops the Flex Tube concept and results in a fully functional prototype CNG storage system. This development encompasses system requirement specifications, materials selection, structural design, process design, prototype fabrication, and preliminary pressure testing. Anticipated Benefits: Flex Tube will allow vehicle manufacturers to readily integrate CNG fuel systems into their vehicles' structure and styling, significnatly reducing space impact and achieving system cost reductions compared to conventional CNG systems. Other applications include body conformable Self Contained Breathing Apparatus for fire fighting, rescue, confined space, and hazardous environment personnel; emergency escape breathing systems; fuel systems, hydraulic/pneumatic energy storage systems;fire suppression/extinguishing systems and like systems requiring lightweight conformable pressure containments.