31
7. REMOVAL AND EVACUATION
When you want to intervene on the refrigerant circuit to carry out a repair - or for
any other purpose - conventional procedures must be used. However, it is important
to follow some of the best practices since flammability is a risky and important
eventuality. The following procedure must be observed: remove the refrigerant;
purge the circuit with inert gas; evacuate; purge again with inert gas; open the
circuit by cutting or brazing. The refrigerant charge must be recovered in the correct
recovery cylinders. The system must be “flushed” with OFN to make the unit safe. This
procedure may need to be repeated several times. Compressed air or oxygen should
not be used for this task. Cleaning is achieved by breaking the vacuum condition in
the system with OFN and continuing to fill until the operating pressure is reached,
creating a vent towards the atmosphere and, finally, recreating the vacuum condition.
This process must be repeated until the refrigerant is inside the system. When the OFN
final charge is used, the system must be discharged to atmospheric pressure to allow
the operation. This procedure is absolutely essential in case of brazing operations
on pipes. Make sure that the outlet for the vacuum pump is not close to sources of
ignition and that it is adequately ventilated.
8. LOADING PROCEDURES
In addition to conventional charging procedures, the following requirements must
be fulfilled:
Make sure that there is no contamination of different refrigerants when using them
charging equipment. Pipes or pipes should be as short as possible to minimize the
amount of refrigerant they contain.
The cylinders must be kept upright.
Make sure the refrigeration system is grounded before charging the system with
refrigerant. Label the system when the charge is complete (if not already done).
Be extremely careful not to overload the refrigeration system.
Before recharging the system, it must be pressure tested with OFN. The
system must be tested for leaks at the end of charging, but before commissioning.
GB
To Next Page
Loading...
