Vivax HPS-41CH120AERI/O3 R410a User Manual page 137

VIVAX

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 pipe‐work are to take place.
Ensure that the outlet for the vacuum pump is not closed to any ignition sources and
there is ventilation available.
16) 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

Ensure that apparatus is mounted securely.

Ensure that seals or sealing materials have not degraded such that they no
longer serve the purpose of preventing the ingress of flammable atmospheres.
Replacement parts shall be in accordance with the manufacturer s
specifications

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.
17)
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.
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