ISO 23550:2004 specifies safety, constructional and performance requirements and testing of safety control or regulating devices and sub-assemblies or fittings (hereafter referred to as controls) for burners and gas-burning appliances using fuel gases as natural gas, manufactured gas or liquefied petroleum gas (LPG). It is not applicable to corrosive and waste gases.

ISO 23550:2004 is applicable to the following controls:

-- automatic shut-off valves;

-- burner controls;

-- flame supervision devices;

-- gas/air ratio controls;

-- pressure governors;

-- manual taps;

-- mechanical thermostats;

-- multifunctional controls;

-- pressure-sensing devices;

-- valve-proving systems;

-- zero governors.

The methods of test given in ISO 23550:2004 are intended for product type testing. Tests intended for production testing are not specifically included.

ISO 23550:2004 is intended to be used in conjunction with the specific control standards of the ISO 23551 series.