This International Standard 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 such fuel gases as natural gas, manufactured gas or liquefied petroleum gas (LPG). It is not applicable to corrosive and waste gases. This International Standard is applicable to the following controls: — automatic shut-off valves; — burner controls; — flame supervision devices; — gas/air ratio controls; — pressure regulators; — manual taps; — mechanical thermostats; — multifunctional controls; — pressure-sensing devices; — valve-proving systems; — zero regulators. The test methods given in this International Standard are intended for product type testing. Tests intended for production testing are not specifically included. NOTE This International Standard is intended to be used in conjunction with the specific control standards of the ISO 23551 series.