HTW HTWDO16A3 Manual De Usuario E Instalacion página 55

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 there is ventilation 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 minimized 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.
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.
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