Refrigerant Piping Precautions; Nitrogen Purging While Brazing - Trane RunTru 17 Series Installer's Manual

Refrigerant Piping Precautions

Hazard of Explosion and Deadly Gases!
Failure to follow all proper safe refrigerant handling practices could result in death or serious
injury. Never solder, braze or weld on refrigerant pipes or any unit components that are above
atmospheric pressure or where refrigerant may be present. Always remove refrigerant by
following the guidelines established by the EPA Federal Clean Air Act or other state or local
codes as appropriate. After refrigerant removal, use dry nitrogen to bring system back to
atmospheric pressure before opening system for repairs. Mixtures of refrigerants and air under
pressure may become combustible in the presence of an ignition source leading to an explosion.
Excessive heat from soldering, brazing or welding with refrigerant vapors present can form
highly toxic gases and extremely corrosive acids.
System Component Damage!
Do not remove the seal caps from the refrigerant connections and piping until prepared to braze
refrigerant pipes to the connections. Excessive exposure to atmosphere (greater than 5 minutes)
may allow moisture or other particulates to contaminate the system, damaging valve seals and
causing ice formation in the system components during operation.

Nitrogen Purging While Brazing

Avoid Unit Damage!
Never braze pipe connections without performing nitrogen purging. Failure to perform this
procedure will damage the unit, resulting in capacity loss and reduced long-term reliability.
While brazing refrigerant pipes, continuously purge them with nitrogen gas. Use a pressure
regulator to maintain a flow rate of 1.76 ft³/h (0.05 m³/h) or more.
88-M4MHW17-1A-EN
WARNING
NOTICE
NOTICE
Nitrogen purging while brazing refrigerant pipes
Nitrogen
Pressure regulator
Stop valve
Flow meter
Installer's Guide
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