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refrigerants. Electronic leak detectors shall be used
to detect flammable refrigerants, but the sensitivity
may not be adequate, or may need re-calibration.
(Detection equipment shall be calibrated in a
refrigerant-free area.) Ensure that the detector is not
a potential source of ignition and is suitable for the
refrigerant used. Leak detection equipment shall be
set at a percentage of the LFL of the refrigerant and
shall be calibrated to the refrigerant employed and
the appropriate percentage of gas (25 % maximum)
is 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. Oxygen free nitrogen
(OFN) shall then be purged through the system both
before and during the brazing process.
12. Removal and evacuation
When breaking into the refrigerant circuit to make
repairs or for any other purpose conventional
procedures shall be used. However, it is important
that best practice is followed since flammability is
a consideration. The following procedure shall be
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