9
Floor and Ceiling Unit
Refrigerant Piping Precautions
Nitrogen Purging While Brazing
WARNING
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.
NOTICE
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 refrigerant pipes
Flow meter
Pressure regulator
Stop valve
Ni
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Nitrogen
NOTICE
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.
