Abstract: A thin metal foil disc etched on both sides in such a way as to form a crossover pattern of rectangular flow passages (or channels) spiraling out, in opposite directions, from the inner diameter to the outer diameter of the disc. In the preferred embodiment, these channels have a depth slightly greater than half of the disc thickness, creating an opening through the thickness of the disc at their points of intersection. This disc design, when stacked appropriately into a filter element, provides substantially lower flow losses than other existing designs. When used as a filter, it performs as an absolute surface filter featuring a tortuous flow path and high degree of porosity. When used as a surface tension device, it offers superior wetting and re-wetting characteristics.

Abstract: A redundant fluid coupling with two coupling assemblies adapted to engage each other and permit fluid flow between the coupling assemblies when they are connected. Each coupling assembly has two functionally independent valves for closing off the fluid flow from the coupling assembly when the coupling assemblies are disconnected. The independent valves are reciprocally operated by coil springs and since they are functionally independent, the failure of one valve of the coupling assembly to operate will not affect the operation of the other valve. The interior portions of each coupling assembly are pivotally mounted which permits the coupling assemblies to be connected together even though they may be offset from each other and/or form an angle with each other.