Abstract: An air and gas feeder device for gas boilers, comprising an air-gas conveyance body which comprises: a boiler coupling face configured to be coupled to a boiler at an intake duct of the boiler; an air intake port connected to an air discharge opening by means of an air passage, the air discharge opening leading out from the boiler coupling face; a gas intake port, configured to be fixed to a gas dispensing duct in fluid communication with a gas discharge opening, which leads out from the boiler coupling face; wherein the air discharge opening is coaxial to, and at least partially surrounded by, the gas discharge opening; the air passage accommodates a flow diverter configured to divert an air flow in output from the air discharge opening in the direction of the gas in output from the gas discharge opening and to impart a rotation to said air flow.

Abstract: A valve (1) for supplying fuel gas to a fuel gas appliance comprises a valve housing (2) which defines a valve chamber (3) within which a main carrier member (20) is axially moveable along a main central axis (4). The main carrier (20) carries a primary valving member (21) and a secondary valving member (22) for co-operating respectively with a primary valve seat (10) and a secondary valve seat (15) for controlling the flow rate of the fuel gas through the valve chamber (3) from a fluid inlet (5) to a main fluid outlet (6). A pilot fluid outlet (7) supplies fuel gas to a pilot jet. A stepper motor (35) comprising a rotor (70) and four independently powered magnetic coils (67) disposed at 90° intervals around the rotor (70) urges the main carrier (20) between a fully open and a closed position in the direction of the arrows B and A, respectively through a screw-drive transmission (37).

Abstract: A valve for supplying fuel gas to a fuel gas appliance comprises a valve housing which defines a valve chamber within which a main carrier member is axially moveable. The main carrier carries a primary and a secondary valving member for co-operating respectively with a primary and a secondary valve seat. A pilot fluid outlet supplies fuel gas to a pilot jet. A stepper motor comprising a rotor and four magnetic coils urges the main carrier between a fully open and closed position. An electro-magnetic coil located in the main carrier magnetically couples primary and secondary end plates to the main carrier. Magnetic decoupling of the primary and secondary end plates from the main carrier permits the main carrier to be urged into the closed position by primary compression springs. The drive transmission comprises a drive shaft from the rotor of the stepper motor and a drive spindle.

Abstract: A valve (1) for supplying fuel gas to a fuel gas appliance comprises a valve housing (2) which defines a valve chamber (3) within which a main carrier member (20) is axially moveable along a main central axis (4). The main carrier (20) carries a primary valving member (21) and a secondary valving member (22) for co-operating respectively with a primary valve seat (10) and a secondary valve seat (15) for controlling the flow rate of the fuel gas through the valve chamber (3) from a fluid inlet (5) to a main fluid outlet (6). A pilot fluid outlet (7) supplies fuel gas to a pilot jet. A stepper motor (35) comprising a rotor (70) and four independently powered magnetic coils (67) disposed at 90° intervals around the rotor (70) urges the main carrier (20) between a fully open and a closed position in the direction of the arrows B and A, respectively through a screw-drive transmission (37).

Abstract: The device comprises a ventilation unit (4) connected with a gas-supplying valve unit (10) via a mixing duct (11). The fixed structures of the ventilation unit (4) and gas-supplying unit (10) and of the mixing duct (11) are of one piece construction (20), so as to give the device (1) an excellent structural compactness, which will make it adaptable to different types of burners (3) and boilers (2).

Abstract: It is described a combustion head consisting of a plurality of balls (10) of ceramic material joined to each other at points of mutual tangency to substantially form a filter bed. On passing through the ceramic head, the combustible gas-combustion air mixture is shared out among a multiplicity of hollow spaces (11) following each other to form a tortuous path, in order to ensure an optimal mixing. At the combustion head exit the gas-air mixture fires forming a flame front extending over the whole external surface (1a) of the combustion head.