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6.2
Preparation and work procedure
A work procedure shall be provided in the preparation stage. All maintenance staff 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
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-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.
Disassemble components with a cutting tool.
4.
Drain, recover and dispose of compressor oil as appropriate.
Figure 17: Tube connecting areas
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.
6.4
Provisions of legislation & leak check requirements
According to EN 378-4, systems with a refrigerant charge of 3 kg or more shall be subject to tightness
inspection at least on an annual basis. The owner/operator shall keep an updated logbook of the
refrigerant system containing all details with regard to maintenance and repair works (quantities and
type of refrigerant changed or transferred, system components changes and replacements etc.). The
EN 378 legislation covers HFO's as well as natural refrigerants.
The F-gas Regulation (EU) No 517/2014 contains additional requirements depending on the system
and stipulates training requirements for alternative refrigerants.
26
fire extinguishers are considered
2
AGL_HP_ST_YHK1E_E_Rev02
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