Abstract: A back-up ring assembly for high pressure gas components includes a first ring having and a second ring. The first ring is split at a first location with a first split angle, while the second ring is split at a second location with a second split angle. The first ring is concentrically positioned adjacent the second ring with the first location being offset relative to the second location. The back-up ring assembly is positionable adjacent to an O-ring in a sealed coupling in a high pressure application.

Abstract: Manual-valve pistons, manual-valve assemblies comprising the manual-valve pistons, and compressed-gas systems comprising the manual-valve-assemblies are disclosed. A manual-valve piston for sealing a compressed-gas conduit may comprise a head portion, a sealing portion, and a stem portion between the head portion and the sealing portion. When the manual-valve piston in a conduit, a gap is defined between a blocking rim of the head portion that allows compressed gas to be trapped in an isochoric thermal isolation zone adjacent to the stem portion. The isochoric thermal isolation zone protects sealing rings seated in the sealing portion from extremely cold compressed gas being introduced into the compressed-gas system. Manual-valve assemblies comprise a manual-valve piston coupled to a coupling body. Compressed-gas systems comprise a fuel-storage vessel, a refueling port, internal conduits, and a manual-valve assembly disposed in one of the internal conduits.

Abstract: Manual-valve pistons, manual-valve assemblies comprising the manual-valve pistons, and compressed-gas systems comprising the manual-valve-assemblies are disclosed. A manual-valve piston for sealing a compressed-gas conduit may comprise a head portion, a sealing portion, and a stem portion between the head portion and the sealing portion. When the manual-valve piston in a conduit, a gap is defined between a blocking rim of the head portion that allows compressed gas to be trapped in an isochoric thermal isolation zone adjacent to the stem portion. The isochoric thermal isolation zone protects sealing rings seated in the sealing portion from extremely cold compressed gas being introduced into the compressed-gas system. Manual-valve assemblies comprise a manual-valve piston coupled to a coupling body. Compressed-gas systems comprise a fuel-storage vessel, a refueling port, internal conduits, and a manual-valve assembly disposed in one of the internal conduits.

Abstract: The invention relates to a fuel cell installation comprising a fuel cell unit (6). Said installation is also provided with a dosing unit (8) which comprises at least one dosing valve (7) and is used to dose a fuel (10) for at least one anode (12) of the fuel cell unit (6), and a starting valve for dosing the fuel (10) for at least one cathode (19) of the fuel cell unit (6) during a starting phase. The aim of the invention is to be able to produce and operate one such fuel cell installation in an economical manner. To this end, at least one throttle element (18) comprising a fixed internal cross-sectional area is used to fix the maximum quantity of fuel that can be dosed in the starting phase.

Abstract: An anode inlet unit for a split fuel cell stack or two fuel cell stacks having two anode inlets. The anode inlet unit has particular application for a small vehicle that requires less power. In one embodiment, the anode inlet unit only includes three injectors. Two of the injectors provide flow control for the hydrogen gas to the two anode inlets to provide the desired turn-down ratio. For a split stack design, the two injectors may provide flow-shifting where the injection of hydrogen gas into the sub-stacks is alternated. The other injector injects a small amount of hydrogen into the cathode side of the fuel cell stack at system start-up to quickly increase the operating temperature of the system. Additionally, two valves can be provided in the unit that receive a flow of air to purge the anode side of the stack for system shut-down.

Abstract: The invention relates to a fuel cell installation comprising a fuel cell unit (6). Said installation is also provided with a dosing unit (8) which comprises at least one dosing valve (7) and is used to dose a fuel (10) for at least one anode (12) of the fuel cell unit (6), and a starting valve for dosing the fuel (10) for at least one cathode (19) of the fuel cell unit (6) during a starting phase. The aim of the invention is to be able to produce and operate one such fuel cell installation in an economical manner To this end, at least one throttle element (18) comprising a fixed internal cross-sectional area is used to fix the maximum quantity of fuel that can be dosed in the starting phase.

Abstract: An anode inlet unit for a split fuel cell stack or two fuel cell stacks having two anode inlets. The anode inlet unit has particular application for a small vehicle that requires less power. In one embodiment, the anode inlet unit only includes three injectors. Two of the injectors provide flow control for the hydrogen gas to the two anode inlets to provide the desired turn-down ratio. For a split stack design, the two injectors may provide flow-shifting where the injection of hydrogen gas into the sub-stacks is alternated. The other injector injects a small amount of hydrogen into the cathode side of the fuel cell stack at system start-up to quickly increase the operating temperature of the system. Additionally, two valves can be provided in the unit that receive a flow of air to purge the anode side of the stack for system shut-down.

Abstract: A fuel cell system that employs one or more injectors in an anode inlet unit for providing hydrogen flow control to a fuel cell stack in the system. At a low flow rate, the duty cycle of one of the injectors is controlled and the other injectors are closed. As the flow rate requirements increase, the duty cycle of the first injector is increased until it is completely open. The duty cycles of the other injectors are then controlled in the same manner in succession. The anode inlet unit may include a valve for directing the hydrogen supply gas to other devices in the fuel cell system. Additionally, a valve can be provided in the unit that receives a flow of air to purge the anode side of the fuel cell stack.