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SAFETY INSTRUCTIONS
used for this task. Purging shall be achieved by breaking 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 charge is used,
the system shall be vented down to atmospheric pressure to enable work. 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 potential ignition sources and there is the
vacuum in the system with OFN and continuing ventilation available.
12. 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 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).
- Extreme care shall be taken not to overfill the refrigerating 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.
13. 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 recovered 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 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
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