POCO line 5961008/00 Benutzerhandbuch Seite 74

7. Removal and evacuation
When breaking into the refrigerant circuit to
make repairs – or for any other purpose –
conventional procedures shall be used. However,
it is important that best practice is followed since
flammability is a consideration. The following
procedure shall be adhered to:
• 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
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