15
For appliances containing
flammable refrigerants
, 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 that ventilation is available.
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 minimise 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
the appropriate purging gas.
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.
Decommissioning
