A premixing apparatus for mixing air with a fuel gas to supply a burner with an air-fuel mixture via a fan includes: a zero governor and a motor-driven type of variable throttle valve, both being disposed in a gas supply passage; and an excess air ratio detecting device for detecting an excess air ratio of the air-fuel mixture, thereby regulating an opening degree of the variable throttle valve so that the excess air ratio of the air-fuel mixture becomes a predetermined value. An arrangement is made to prevent an ignition failure from occurring in an attempt to perform an ignition operation in a state in which, due to a trouble with the variable throttle valve of remaining opened or remaining closed, the excess air ratio of the air-fuel mixture becomes too small or too excessive. The variable throttle valve is provided with a sensing device.

A driving device using temperature measurement, a driving method using temperature measurement and a dual-gas-source valve control system, wherein the device includes at least two thermocouple components; and a magnetic-drive assembly, wherein each thermocouple component is connected with the magnetic-drive assembly, the thermocouple components are capable of driving the magnetic-drive assembly to generate a magnetic flux according to an external temperature, and some of the thermocouple components drive the magnetic-drive assembly to generate a magnetic flux that is capable of being offset with a magnetic flux generated by the magnetic-drive assembly driven by the other of the thermocouple components.

.[.The cooking appliance (1) having a control panel (2) is equipped with one or more gas flow (Q) regulating valves, wherein the rotary regulating plug (6) is provided with various peripheral through holes (16-19). The control knob (9) being interchangeable for fitting to the actuating shaft (7), is chosen from the two units available, one and the other permitting different angular limit positions of the regulating plug (6) for the supply of a constant minimum gas flow Qmin, adjusted each one for a different type of gas N gas or LP gas. The outlet conduit (5) of the valve is equipped with a further injector nozzle (21,23) for adjusting a constant gas flow Qmax to be fed into the conduit (25) of the correspondent burner, when the cooking appliance is supplied with a LP gas..]. .Iadd.A valve adapted to regulate the flow of both a natural gas and a liquefied petroleum gas. According to one implementation the valve includes a valve body having a rotatable regulating organ positioned between a valve inlet and a valve outlet, the valve outlet having a first restriction and a second restriction successive to the first restriction, the first restriction including a first hole calibrated to provide a given maximum flow rate of the natural gas at a first pressure in the absence of the second restriction, the second restriction removeably attached to the valve outlet, the second restriction including a second hole calibrated to provide a given maximum flow rate of the liquefied petroleum gas at a second pressure..Iaddend.

A mechanical valve assembly for the control of a gas flow to a gas appliance, the mechanical valve assembly comprising: a housing; a gas inlet port associated with the housing; a gas outlet port associated with the housing; a timer-controlled valve operable to open and close a gas flow between the inlet port and outlet port; and a manually-operated emergency shut-off valve positioned between the inlet port and the outlet port, ahead of the timer-controlled valve relative to a direction of the gas flow through the mechanical valve assembly.

The invention relates to a gas control unit of modular design, in particular for controlling the quantity of gas to be fed to a gas burner, having a pneumatically controlled gas control valve that is configured as a whole as a module and is usable in such a gas control unit of modular design together with a gas safety valve.

The present disclosure discloses a gas mixing device and a gas water heating device. In which, a gas mixing device, comprises: a shell provided with a fuel gas channel for inputting fuel gas, an air channel for inputting air and a gas mixing channel, the fuel gas channel being provided with a first cut-off portion capable of changing a flow area, and the air channel being provided with a second cut-off portion capable of changing a flow area; a moving part movable in the shell, the moving part simultaneously changing the flow areas of the first cut-off portion and the second cut-off portions by moving. The gas mixing device and the gas water heating device can provide a higher regulation ratio, thereby solving the problem that the water temperature is too high in summer.

A gas delivery apparatus has a delivery pipe that extends from a gas entrance end to a gas delivery end along which an entrance component, a pressure regulator and a flow rate regulator are present, coordinated with each other in order to supply on each occasion the desired quantity of gas to a burner of an apparatus fed with gas. or p with an air-gas mixture.

A combustion staging system has: a splitter; pilot and mains fuel manifolds; mains flow control valves; and fuel servo line. Each mains flow control valve has a chamber containing a piston, the chamber to a piston mains side fed by the mains fuel manifold, and the chamber to a piston servo side fed by the servo line. The piston has an open pilot-and-mains position allowing flow from the chamber mains side to the respective injector mains discharge orifice. The piston prevents flow from the chamber mains side. The piston is movable under a pressure change in the servo line relative to the mains fuel manifold. The system has a servo pump and a hydraulic motor driving it. The servo pump changes fuel pressure. Motive power for the hydraulic motor is fuel diverted from a fuel pump high pressure output, the motor returning the diverted fuel to a low pressure input.

A fuel metering system includes a metering valve having a first inlet fluidly coupled to a source of fluid at a first pressure, a second inlet, a first outlet and a second outlet. The metering valve includes a slot, and a valve body movable to control an amount of fluid supplied to the first and second outlet. The fuel metering system includes a servo valve fluidly coupled to the second inlet and to a second source of fluid at a second pressure. The servo valve is in fluid communication with the second inlet and a body of the servo valve is movable to supply a fluid to move the valve body. The slot is configured to variably restrict the flow of the fluid through the second outlet to balance a force applied by a biasing member. The fuel metering system includes a fixed flow restriction downstream of the second outlet.

A gas valve for a gas stove, comprising a valve housing, wherein the valve housing has a gas inlet and a gas outlet, and a gas regulating unit, wherein the gas regulating unit has a cylindrical outer surface, wherein the gas regulating unit is rotatable supported in the valve housing by means of the outer surface, wherein the gas regulating unit has a plurality of gas outlet openings, wherein the gas regulating unit is rotatable into a plurality of flame positions, wherein each gas outlet opening is assigned to one determined flame position, wherein in each flame position the gas inlet is connected to the gas outlet by means of the gas outlet opening which is assigned to the one determined flame position, and wherein the gas outlet openings have cross-sectional areas which differ from each other in order to achieve different flow rates of gas through the gas valve in the individual flame positions.