AGL_AC_ST_YRH_EN_Rev01
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6.1 Qualification of workers
Personnel working on the maintenance, repair and decommissioning of a flammable refrigerant
system shall be adequately trained. Any work procedure affecting safety shall only be executed by
qualified and trained personnel in compliance with national or other equivalent certification systems.
Examples of such work procedures include:
▪
breaking into the refrigerating circuit;
▪
opening sealed components;
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opening ventilated enclosures
…
6.2 Preparation and work procedure
A work procedure shall be provided in the preparation stage. All maintenance personnel and others
working at the site shall be instructed on the nature of the work being carried out.
If any work is to be conducted on the refrigeration systems or any associated parts, appropriate fire
extinguishing equipment shall be provided. Dry powder or CO
2
fire extinguishers are considered
appropriate. Confirm that appropriate fire extinguishing equipment is available near the work area.
Prior to starting to work on systems containing flammable refrigerants, safety checks are necessary
to ensure that the risk of ignition is minimized.
Work shall be undertaken under a controlled procedure so as to minimize the risk of a flammable
gas or vapour being present while the work is being performed.
Avoid working on systems filled with flammable refrigerant in a confined space.
6.3 Disassembling system components
When disassembling system components please follow the main steps described hereunder:
1.
Recover refrigerant and evacuate system using an A2L- or A3-dedicated recovery unit and
vacuum pump. All the refrigerant shall be recovered to avoid significant release. Ensure that the
outlet of the vacuum pump is not close to any potential ignition source and that ventilation is
available.
2.
Flush system with inert gas (dry nitrogen). Compressed air or oxygen shall not be used for
purging refrigerant systems.
3.
For A2L and A3 refrigerant systems, the procedure of evacuation and flushing with oxygen-free
nitrogen may need to be repeated until no refrigerant is present in the system. When the final
oxygen-free nitrogen charge is used, the system shall be vented down to atmospheric pressure
to enable work to take place.
4.
Disassemble components with a cutting tool.
5.
Drain, recover and dispose of compressor oil as appropriate.
To disconnect:
▪
Using a pipe cutting tool, cut off the suction and discharge
lines in such a manner that the new compressor can easily be
re-connected into the system.
▪
Heat joint areas 2 and 3 slowly and uniformly until the braze
material softens and the tube end can be pulled out from the
fitting.
To reconnect:
▪
Recommended brazing material: Silfos with minimum 5 % silver or silver braze used on other
compressors.
▪
Due to the different thermal properties of steel and copper, brazing procedures may have to be
changed from those commonly used.
NOTE: Since the discharge stub contains a check valve, care must be taken not to overheat
it to prevent brazing material from flowing into it.
Figure 19: Tube connecting areas
