Abstract: A breathing gas supply system for an aircraft includes a plurality of oxygen concentrating apparatus, each of which in use, is operable to supply oxygen enriched gas to a breathing gas supply. Each oxygen concentrating apparatus includes at least two active molecular sieve beds which are operable so that while one sieve bed is adsorbing non-oxygen gas from a pressurized gas supply, the or another bed is being purged of non-oxygen gas by subjecting the bed to lower pressure. Each oxygen concentrating apparatus includes an oxygen enriched gas flow control device which permits the flow of oxygen enriched gas produced by the oxygen concentrating apparatus to the breathing gas supply and permits a restricted flow of oxygen enriched gas from the breathing gas supply to the oxygen concentrating apparatus. Oxygen enriched gas produced by the adsorbing sieve bed flows direct to the bed being purged.

Abstract: A breathing gas supply system for an aircraft includes a plurality of oxygen concentrating apparatus, each of which in use, is operable to supply oxygen enriched gas to a breathing gas supply. Each oxygen concentrating apparatus includes at least two active molecular sieve beds which are operable so that whilst one sieve bed is adsorbing non-oxygen gas from a pressurized gas supply, the or another bed is being purged of non-oxygen gas by subjecting the bed to lower pressure. Each oxygen concentrating apparatus includes an oxygen enriched gas flow control device which permits the flow of oxygen enriched gas produced by the oxygen concentrating apparatus to the breathing gas supply and permits a restricted flow of oxygen enriched gas from the breathing gas supply to the oxygen concentrating apparatus. Oxygen enriched gas produced by the adsorbing sieve bed flows direct to the bed being purged.

Abstract: A method of testing a system including a plurality of modules, each of which in use, produces from an air supply, a product gas which is one of oxygen gas and oxygen enriched gas, the method including providing to an inlet to at least one of the modules, when the module is not in use, a restricted air supply, and at an outlet of the module, sensing at least one of the oxygen concentration and product gas pressure, and analysing the sensed oxygen concentration and/or product gas pressure during a test period to determine the potential performance of the module in use.

Abstract: A method of controlling a gas adsorption apparatus including a sieve bed containing molecular sieve bed material, the bed being cyclically operable in a charge mode to adsorb non-product gas from an air supply thereby to increase the concentration of a product gas in a product gas supply which passes to a product gas line and in a vent mode to desorb the adsorbed non-product gas which passes to a non-product gas line, and there being a passage to permit a restricted amount only of the product gas supply to pass from the product gas supply line to the bed when operating in vent mode, and wherein the method includes operating a variable flow device to permit an increased amount of the product gas supply to pass to the bed when operating in vent mode, under predetermined conditions.

Abstract: An apparatus for supplying pressurized gas to a plurality of gas outlets from an upstream gas supply, in which each of the plurality of gas outlets in use is connected to a common gas feed line via a respective valve, each valve being adapted to close to prevent the flow of gas downstream of the valve in the event of the integrity of the feed line being breached downstream of the respective valve, to prevent the escape of gas from the breached feed line, and wherein each valve includes a valve member which is moveable into engagement with a valve seat to close the valve, and a valve member damping means to resist movement of the valve member into engagement with the valve seat.

Abstract: An apparatus for supplying pressurized gas to a plurality of gas outlets from an upstream gas supply, in which each of the plurality of gas outlets in use is connected to a common gas feed line via a respective valve, each valve being adapted to close to prevent the flow of gas downstream of the valve in the event of the integrity of the feed line being breached downstream of the respective valve, to prevent the escape of gas from the breached feed line, and wherein each valve includes a valve member which is moveable into engagement with a valve seat to close the valve, and a valve member damping means to resist movement of the valve member into engagement with the valve seat.

Abstract: A method of testing a system including a plurality of modules, each of which in use, produces from an air supply, a product gas which is one of oxygen gas and oxygen enriched gas, the method including providing to an inlet to at least one of the modules, when the module is not in use, a restricted air supply, and at an outlet of the module, sensing at least one of the oxygen concentration and product gas pressure, and analysing the sensed oxygen concentration and/or product gas pressure during a test period to determine the potential performance of the module in use.

Abstract: A method of controlling a gas adsorption apparatus including a sieve bed containing molecular sieve bed material, the bed being cyclically operable in a charge mode to adsorb non-product gas from an air supply thereby to increase the concentration of a product gas in a product gas supply which passes to a product gas line and in a vent mode to desorb the adsorbed non-product gas which passes to a non-product gas line, and there being a passage to permit a restricted amount only of the product gas supply to pass from the product gas supply line to the bed when operating in vent mode, and wherein the method includes operating a variable flow device to permit an increased amount of the product gas supply to pass to the bed when operating in vent mode, under predetermined conditions.

Abstract: A method of reducing the duration of the thermal stabilization phase of a liquefied gas converter (13) is characterized in that the method comprises providing in a feed line (11) between a source (12) of liquefied gas and the liquefied gas converter (13), an uninsulated flow region (16) through which at least a portion of the liquefied gas passes during filling.