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IMPORTANT INSTRUCTIONS
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NOTE Examples of leak detection fluids are
– bubble method,
– fluorescent method agents.
If a leak is suspected, all naked flames shall be removed/extinguished.
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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 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 be followed, since
flammability is a consideration.
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The following procedure shall be adhered to:
a) safely remove refrigerant following local and national regulations;
b) purge the circuit with inert gas;
c) evacuate (optional for A2L);
d) purge with inert gas (optional for A2L);
e) open the circuit by cutting or brazing.
The refrigerant charge shall be recovered into the correct recovery cylinders if venting is not allowed by
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local and national codes. For appliances containing flammable refrigerants,the system shall be purged with
oxygen-free nitrogen to render the appliance safe for flammable refrigerants. This process might need to be
repeated several times.
Compressed air or oxygen shall not be used for purging refrigerant systems.
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For appliances containing flammable refrigerants, refrigerants purging shall be achieved by breaking the
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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.
Ensure that the outlet for the vacuum pump is not close to any potential ignition sources and that ventilation
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is available.
Charging procedures
In addition to conventional charging procedures, the following requirements shall be followed.
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Ensure that contamination of different refrigerants does not occur when using charging equipment.
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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.
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Ensure that the REFRIGERATING SYSTEM is earthed prior to charging the system with refrigerant.
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Label the system when charging is complete (if not already).
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Extreme care shall be taken not to overfill the REFRIGERATING SYSTEM.
Prior to recharging the system, it shall be pressure-tested with the appropriate purging gas. The system shall
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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.
Decommissioning
Before carrying out this procedure, it is essential that the technician is completely familiar with the
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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
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prior to re-use of recovered refrigerant. It is essential that electrical power is available before the task is
commenced.
a) Become familiar with the equipment and its operation.
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