Abstract: A gaseous fuel mixture burner which includes a mixer device into which gas is injected so as to provide a gaseous vortex formation within the mixer, air being drawn into the device and mixed with the gas by the low pressure region created within the vortex.

Abstract: A control unit for a gas-fired appliance comprises a service tap that acts also as a flame failure device. The flame failure device controls gas flow to a gas governor which is an integral part of the unit and associated with the gas governor is a low gas pressure cut-off. The unit also incorporates a modulating gas flow control valve operatively coupled to a thermostat which, in the case of a gas-fired water heater, is responsive to water temperature in the heater. When used with a water heater, the unit also includes a further thermostat set to terminate gas flow in the event that a predetermined maximum water temperature is exceeded.

Abstract: A process for coating a surface with a glass ceramic coating incorporating a catalyst, the process consisting of formulating glass ceramic frit to produce vitrification at low temperatures thereby providing a porous glass ceramic coating to act as a carrier for the catalyst. The catalyst may be one able to bring about oxidation of contamination produced by cooking food.