14
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 ig-
nition sources and there is ventilation available.
13. Charging procedures
In addition to conventional charging procedures, the following re-
quirements shall be followed. Ensure that contamination of dif-
ferent refrigerants does not occur when using charging equip-
ment. 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 sys-
tem.
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.
14. Decommissioning
Before carrying out this procedure, it is essential that the techni-
cian 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 reuse of
reclaimed refrigerant. It is essential that electrical power is avail-
able 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 han-
dling refrigerant cylinders.
All personal protective equipment is available and being used cor-
rectly.
The recovery process is supervised at all times by a competent per-
son.
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.