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
pipework are to take place.
• Ensure that the outlet for the vacuum pump is not close to
any ignition sources and there is ventilation available.
CHARGING PROCEDURES
• 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 upright.
• Ensure that the refrigeration system is earthed prior to
charging the system with refrigerant.
• Label the system when charging is complete (if not
already).
• Extreme care shall be taken not to overfill the refrigeration
system.
• Prior to recharging the system, it shall be pressure tested
with OFN. 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.
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.
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 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
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