ISO 23550:2011 specifies safety, constructional and performance requirements and testing of safety control or regulating devices and sub-assemblies or fittings 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.ISO 23550:2011 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 ISO 23550:2011 are intended for product type testing. Tests intended for production testing are not specifically included.