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 opera-
tion 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.
Removal and evacuation
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 refriger-
ation 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 commis
-
sioning. A follow up leak test shall be carried out prior to leaving the site.
Charging procedures
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 refriger-
ants 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.
Decommissioning
Your home in sync
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