The cooling system of the white household appliances, like the conditioner and refrigenerators are usually made of steel, aluminum and other non ferrous metals. The whole system is composed by full closed pipeline. Such strict requirements rely on the excellent welding process to ensure a good quality. 

    Brazing welding and gas welding are mostly applied on pipes connections as well as the whole machine quality in case of a failure caused by careless welding. The recent produced air-conditioner and refrigerators most adopt oxygen-acetylene as heat source for braze welding, but this brings an increasing pressure to companies because of the energy shortage and environment pollution. 

    Therefore, the oxy-hydrogen, with advantages of saving energy and protecting environment, start to replace the oxy-acetylene and become a main welding fuel for steel and aluminum in household air-conditioners and refrigerators.