1300 859 933
www.evoheat.com.au
Fusion-i Series Manual
Page 24
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.
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.
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 always supervised 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.
