Norsup P13X/32 Installations- Und Gebrauchsanweisung Seite 33

5. MAINTENANCE AND INSPECTION
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 adhered to:
. Remove refrigerant;
. Purge the circuit with inert gas;
. Evacuate;
. Purge again with inert gas;
. Open the circuit by cutting or brazing.
The refrigerant charge shall be recovered into the correct recovery cylinders. The system shall
be "flushed" with OFN to render the unit safe. This process may need to be repeated several
times. Compressed air or oxygen shall not be used for this task.
Flushing shall be achieved by breaking the vacuum in the system with OFN and continuing to fill
until the working pressure is achieved, then venting to atmosphere, and finally pulling down to a
vacuum. This process shall be repeated until no refrigerant is within the system.
When the final OFN charge is used, the system shall be vented down to atmospheric
pressure to enable work to take place. This operation is absolutely vital if brazing
operations on the pipe-work are to take place.
Ensure that the outlet for the vacuum pump is not close to any ignition sources and there is
ventilation available. working on them.
Labelling
Equipment shall be labelled stating that it has been de-commissioned and emptied of
refrigerant. The label shall be dated and signed. Ensure that there are labels on the
equipment stating the equipment contains flammable refrigerant.
Recovery
When removing refrigerant from a system, either for servicing or decommissioning, it is
recommended good practice that all refrigerants are removed safely.
When transferring refrigerant into cylinders, ensure that only appropriate refrigerant
recovery cylinders are employed. Ensure that the correct number of cylinders for holding the
total system charge is available. All cylinders to be used are designated for the
recovered refrigerant and labelled for that refrigerant (i.e. special cylinders for the recovery of
refrigerant). Cylinders shall be complete with pressure relief valve and associated shut- off valves
in good working order. Empty recovery cylinders are evacuated and, if possible,
cooled before recovery occurs.
The recovery equipment shall be in good working order with a set of instructions
concerning the equipment that is at hand and shall be suitable for the recovery of
flammable refrigerants. In addition, a set of calibrated weighing scales shall be available and
in good working order. Hoses shall be complete with leak-free disconnect couplings and in
good condition. Before using the recovery machine, check that it is in satisfactory working
order, has been properly maintained and that any associated electrical
components are sealed to prevent ignition in the event of a refrigerant release. Consult
manufacturer if in doubt.
The recovered refrigerant shall be returned to the refrigerant supplier in the correct
recovery cylinder, and the relevant Waste Transfer Note arranged. Do not mix refrigerants in
recovery units and especially not in cylinders.
If compressors or compressor oils are to be removed, ensure that they have been
evacuated to an acceptable level to make certain that flammable refrigerant does not
remain within the lubricant. The evacuation process shall be carried out prior to returning the
compressor to the suppliers. Only electric heating to the compressor body shall be
employed to accelerate this process. When oil is drained from a system, it shall be carried out
safely.
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