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confirmed.
Leak detection fluids are suitable for use with most refrigerants
but the use of detergents containing chlorine shall be avoided
as the chlorine may react with the refrigerant and corrode
the copper pipe-work.
If a leak is suspected, all naked flames shall be
removed/extinguished.
If a leakage of refrigerant is found which requires brazing, all of
the refrigerant shall be recovered from the system, or isolated
(by means of shut off valves) in a part of the system remote
from the leak. For appliances containing
flammable
refrigerants
, oxygen free nitrogen (OFN) shall then be purged
through the system both before and during the brazing
process.
Removal and evacuation
When breaking into the refrigerant circuit to make repairs
– or
for any other purpose
–conventional procedures shall be used.
However, for
flammable refrigerants
it is important that best
practice is followed since flammability is a consideration. The
following procedure shall be adhered to:
•
remove refrigerant;
•
purge the circuit with inert gas;
•
evacuate;
•
purge again with inert gas;
•
open the circuit by cutting or brazing.
The refrigerant charge shall be recovered into the correct
recovery cylinders. For appliances containing
flammable
refrigerants
, the system shall be “flushed” with OFN to render
the unit safe. This process may need to be repeated several
times. Compressed air or oxygen shall not be used for purging
refrigerant systems.
