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Are there scratches or dents on the existing pipes?
Is it possible to operate the existing air conditioner?
y After the existing air conditioner is operated in cooling
mode for approx. 30 minutes or longer,* recover the
refrigerant.
y For cleaning the pipes and recovering oil
y Refrigerant recovery: Pump down method
y Remove the existing air conditioner from the piping
and carry out flushing (nitrogen pressure 0.5 MPa) to
remove any remains inside of the pipe.
Note: In case of twin pipes, also be sure to flush the
branching pipe.
Connect the indoor / outdoor units to the existing pipe.
y Use a flare nut attached to the main unit for the indoor
/ outdoor units. (Do not use the flare nut of the existing
pipe.)
y Re-machine the flare machining size to size for R32.
y (Airtight test), Vacuum dry, Refrigerant charge, Gas
leak check
Test run
Was largely discolored oil or a large quantity
of remains discharged? (When the oil deteriorates,
the color of the oil changes to a muddy
or black color.)
Existing pipes: Cannot be used.
y Use new pipes.
Clean the pipes or use new pipes.
Piping necessary to change the flare nut / machining
size due to pipe compression
1) Flare nut width: H
H
(mm)
Copper pipe
outer diameter
Ø6.4 Ø9.5 Ø12.7 Ø15.9
For R32, R410A 17 22 26 29
For R22
Same as above
24 27
2) Flare machining size: A
A
(mm)
Copper pipe outer
diameter
Ø6.4 Ø9.5 Ø12.7 Ø15.9
For R32, R410A 9.1 13.2 16.6 19.7
For R22 9.0 13.0 16.2 19.4
Becomes a little larger for R32
Do not apply refrigerator oil to the flare surface.
(If there is discharge of remains, it is judged that a
large quantity of remains are present.)
YES
YES
NO
NO
NO
YES
Nitrogen gas pressure 0.5 MPa
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