Removal And Evacuation; Charging Procedures - Oceanic OCEACLIM100W1 Guide D'utilisation

equipment shall be calibrated in a refrigerant-free area.) Ensure that the detector is not a
potential source of ignition and is suitable for the refrigerant used. Leak detection equipment
shall be set at a percentage of the LFL of the refrigerant and shall be calibrated to the
refrigerant employed and the appropriate percentage of gas (25 % maximum) is confirmed.
Leak detection fluids are suitable for use with most refrigerants but the use of detergents
containing chlorine shall be avoided as the chlorine may react with the refrigerant and corrode
the copper pipe-work. If a leak is suspected, all naked flames shall be removed/extinguished.
If a leakage of refrigerant is found which requires brazing, all of the refrigerant shall be
recovered from the system, or isolated (by means of shut off valves) in a part of the system
remote from the leak. Oxygen free nitrogen (OFN) shall then be purged through the system
both before and during the brazing process.

7 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 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.

8 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 minimize 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.
9 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.
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