SOUTH AFRICA: Refrigerant supplier A-Gas South Africa has raised awareness of brazing and debrazing best practices to prevent potential accidents.

The advice follows recent incidents in Australia and a subsequent safety report issued by SafeWork NSW after workers had been severely burnt when a mixture of refrigerant and compressor oil was expelled and ignited while servicing air conditioning systems.

The systems contained the non-flammable refrigerant R22 which, when mixed with oil, was ignited by an oxy-acetylene torch used by the workers’ to unsweat the copper fittings, when replacing the refrigerant compressor.

“Any brazing or debrazing must only be carried out after recovery of any excess gas in the system, and following the introduction of an inert gas such as oxygen-free nitrogen (OFN) into the pipework,” says A-Gas South Africa national sales manager Michael Labacher on the company’s website.

“It is critical to expel oxygen from the internal system so as to prevent flash-ignition of hot oil, a particular problem when debrazing welded connections on replacement compressors,” he writes, pointing out that OFN inhibits oxidisation of internal copper pipes and fittings.

A-Gas states that while unsweating copper fittings is “an established and accepted practice” it is extremely hazardous and unsafe as heat from a naked flame can result in the ignition of any expelled refrigerant and oil mist.

“A side effect is that trace quantities of refrigerant will also decompose as a result, and generate toxic fumes,” says Michael Labacher.

Further information here.

Related stories:

Safety alert follows ac “explosions”