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.
Removal of refrigerant shall be according to Removal and evacuation.
11. 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:
-Safely remove refrigerant following local and national regulations;
-Evacuate;
-Purge the circuit with inert gas (optional for A2L);
-Evacuate (optional for A2L);
-continuously flush or purge with inert gas when using flame to open circuit; and
-open the circuit.
The refrigerant charge shall be recovered into the correct recovery cylinders if venting is not
allowed by local and national codes. For appliances containing flammable refrigerants, the
system shall be purged with oxygen-free nitrogen flammable refrigerants. This process might
compressed air or oxygen shall not be used for purging refrigerant systems.
12. Charging procedures
In addition to conventional charging procedures, the following requirements shall be followed.
Ensure that contamination of different refrigerants does not occur when using charging
equipment. Hoses or lines shall be as short as possible to minimise the amount of refrigerant
contained in them. Cylinders shall be kept in an appropriate position according to the
instructions. Ensure that the refrigeration system is earthed prior to charging the system with
refrigerant. Label the system when charging is complete (if not already). Extreme care shall
be taken not to overfill the refrigeration system. Prior to recharging the system, it shall be
pressure tested with OFN. The system shall be leak tested on completion of charging but
prior to commissioning. A follow up leak test shall be carried out prior to leaving the site.
13.Decommissioning
Before carrying out this procedure, it is essential that the technician is completely familiar
with the equipment and all its detail. It is recommended good practice that all refrigerants
are recovered safely.
Prior to the task being carried out, an oil and refrigerant sample shall be taken in case
analysis is required prior to re-use of reclaimed refrigerant. It is essential that electrical
power is available before the task is commenced.
a) Become familiar with the equipment and its operation.
b) Isolate system electrically.
c) Before attempting the procedure ensure that: Mechanical handling equipment is available,
if required, for handling refrigerant cylinders; all personal protective equipment is available
and being used correctly; the recovery process is supervised at all times by a competent
person; recovery equipment and cylinders conform to the appropriate standards.
d) Pump down refrigerant system, if possible.
For appliances containing flammable refrigerants, refrigerants purging shall be achieved by
breaking the vacuum in the system with oxygen-free nitrogen and continuing to fill until the
working pressure is achieved, then venting to atmosphere, and finally pulling down to a
vacuum (optional for A2L). This process shall be repeated until no refrigerant is within the
system (optional for A2L). When the final oxygen-free nitrogen charge is used, the system
shall be vented down to atmospheric pressure to enable work to take place. The outlet for
the vacuum pump shall not be close to any potential ignition sources, and ventilation shall
be available.
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