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Idiomas disponibles
Check that cabling will not be subject to wear, corrosion, excessive pressure, vibration, sharp edges or any
other adverse environmental effects. The check shall also take into account the effects of ageing or continual
vibration from sources such as compressors or fans.
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.
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.
Prior to recharging the system it shall be pressure tested with OFN.
DD.12 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.
e) If a vacuum is not possible, make a manifold so that refrigerant can be removed from various parts of the system.
f) Make sure that cylinder is situated on the scales before recovery takes place.
g) Start the recovery machine and operate in accordance with manufacturer's instructions.
h) Do not overfill cylinders. (No more than 80 % volume liquid charge).
i) Do not exceed the maximum working pressure of the cylinder, even temporarily.
j) When the cylinders have been filled correctly and the process completed, make sure that the cylinders and the
equipment are removed from site promptly and all isolation valves on the equipment are closed off.
k) Recovered refrigerant shall not be charged into another refrigeration system unless it has been cleaned and checked.
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.
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 are 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
05
Safety Warning
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