Abstract: A water heater of the instantaneous gas type without a permanent pilot light includes: a small turbo-alternator through which the water drawn off passes; an arrangement for using the current from the turbo-alternator for lighting a main pilot light; a valve arrangement for using the flow of water drawn off to admit the gas to the main pilot light and a differential pneumatic valve for controlling the intake of gas to the burner. This differential pneumatic valve is itself actuated by a venting, at the level of an auxiliary pilot light, controlled by an electrovalve fed with the current i. The electrovalve is energized by the positive half waves of the current, chosen so that the cycles of its openings and closings can follow one another at a high rate and the durations of its openings are regulated by modifying the amplitude of the half waves by resistance responsive to the temperature of the drawn off water.

Abstract: The hydraulic microturboalternator comprises a plastic molding which wraps the laminated stator (2) of the microalternator while providing an interior water chamber (20) intended to receive the rotor (1) and of which the inner diameter is at least equal to the outer diameter of the rotor increased by a fraction of the radial thickness of an airgap of particular shape and size, said molded body being sealingly closed by a casing (14) which limits a water chamber (21) containing the turbine (15) and which communicates with the chamber (20). Application is to gas-operated apparatuses for the production of hot water but designed to function without a permanent ignition pilot.

Abstract: The invention relates to a pressure responsive assembly for controlling the supply of gas to a gas appliance. A pressure responsive device includes a sealed air bulb positioned to monitor the pilot flame of the appliance. A capillary tube connected at one end to the sealed bulb has its other end supported in the central channel of a small plug. An expandable diaphragm or membrane, having a central aperture aligned with the axis of the plug, is disposed to bear against a button member positioned between the diaphragm and an actuating lever set to control operation of a gas supply valve. The button member is shaped with channels, grooves or apertures to establish a through air connection between the capillary tube and external air when the diaphragm is in a deflated condition.

Abstract: The invention relates to a forced draft household gas boiler having a sealed enclosure for the combustion assembly of the boiler.A sealed shell (15) envelopes a cylindrical heat exchanger (6) and is suspended in the upper half of a frame (1) from a horizontal plate (4) so that a central inlet opening (11) of the heat exchanger is in the axis of an outlet tube (32) of a fan (29) which directs an air/gas mixture into the burner. An outlet opening (23) for the combustion products collected in the sealed shell (15) is located within the circumference of the shell and at least approximately in the axis of an evacuation pipe (18) for evacuating combustion products external of the boiler.

Abstract: A gas-tight chamber for a heat exchanger has a shell (12) forming the gas-tight chamber made of a light flexible or semirigid material such as rubber or thin silicone-treated sheet material which, because of its low weight and relative flexibility, absorbs all the vibrations produced and maintained by the burners, which eliminates the noise. The exchangers have a layer of longitudinal water tubes arranged concentrically around a central burner.

Abstract: A control mechanism for a gas-fired hot water heater, which operates without a permanent burner pilot, has an electrical circuit for selectively operating an igniter in response to gas pressure in the heating system. The water heater has a main chamber for providing gas to the igniter pilot and the burner element, and a secondary chamber for providing gas to a safety pilot. Circuitry responsive to a high gas pressure in the main chamber activates the igniter and circuitry responsive to a high gas pressure in the secondary chamber interrupts operation of the igniter. Continuous operation of the igniter element is thereby prevented, for example, due to a low gas pressure condition.