7
• When breaking into the refrigerant circuit to make repairs – or for any other purpose – conventional procedures
is a consideration. The following procedure shall be adhered to:
a. remove refrigerant;
b. purge the circuit with inert gas;
c. evacuate;
d. purge with inert gas;
e. open the circuit by cutting or brazing.
f. The refrigerant charge shall be recovered into the correct recovery cylinders.
g. This process may need to be repeated several times. Compressed air or oxygen shall not be used for
purging efrigerant systems.
•
• This process shall be repeated until no refrigerant is within the system.
•
enable work to take place.
• Ensure that the outlet for the vacuum pump is not close to any potential ignition sources and that ventilation is
available.
• In addition to conventional charging procedures, the following requirements shall be followed.
• 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.
• Cylinders shall be kept in an appropriate position according to the instructions.
• Ensure that the refrigerating system is earthed prior to charging the system with refrigerant.
• Label the system when charging is complete (if not already).
•
• Prior to recharging the system, it shall be pressure-tested with the appropriate purging gas.The system shall 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.
• 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 recovered refrigerant. It is essen-
tial 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 re
covery 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 instructions.
i. Do not exceed the maximum working pressure of the cylinder, even temporarily.
equipment are removed from site promptly and all
k. isolation valves on the equipment are closed off.
l. Recovered refrigerant shall not be charged into another refrigerating 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.
• -
• When removing refrigerant from a system, either for servicing or decommissioning, it is recommended good prac-
tice that all refrigerants are removed safely.
• When transferring refrigerant into cylinders, ensure that only appropriate refrigerant recovery cylinders are em-
ployed. 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
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 com-
ponents 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 rele-
vant 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
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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