Removal and evacuation
Conventional procedures must be used when breaking into the refrigerant circuit to
make repairs or for any other purpose. Best practices must be followed since
flammability is a consideration. The procedures below must be followed.
Remove the refrigerant.
Purge the circuit with inert gas.
Evacuate the system.
Purge again with inert gas.
Open the circuit by cutting or brazing.
Recover the refrigerant charge into the correct recovery cylinders. Flush the system with
OFN to ensure appliance safety. This process may need to be repeated several times.
Compressed air or oxygen should 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, venting to the atmosphere, then pull down to a vacuum. This
process must be repeated until no refrigerant is within the system. When the final OFN
charge is used, the system should be vented down to atmospheric pressure to allow for
servicing. This step is absolutely vital if brazing operations on the pipework are required.
Ensure that the vacuum pump outlet is not close to any ignition sources and there is
adequate ventilation available.
In addition to conventional charging procedures, the below requirements must not be
Ensure that contamination of different refrigerants does not occur when using
charging equipment. Hoses or lines must be as short as possible to minimise the
amount of refrigerant contained within.
Cylinders must be kept upright.