85
(2) To fasten the flare nuts, apply specified torque.
● When removing the flare nuts from the tubing connections, or when tightening them after
connecting the tubing, be sure to use two spanners.
When tightening the flare nuts, use a torque wrench.
If the flare nuts are over-tightened, the flare may be damaged, which could result in
refrigerant leakage and cause injury or asphyxiation to room occupants.
● For the flare nuts at tubing connections, be
sure to use the flare nuts that were supplied
with the unit, or else flare nuts for R410A,
R32 (type 2). The refrigerant tubing that is
used must be of the correct wall thickness as
shown in the table at right.
Because the pressure is approximately 1.6
times higher than conventional refrigerant
R22 pressure, the use of ordinary flare nuts
(type 1) or thin-walled tubes may result in
tube rupture, injury, or asphyxiation caused
by refrigerant leakage.
● In order to prevent damage to the flare caused by over-tightening of the flare nuts, use the
table on the right as a guide when tightening.
● When tightening the flare nut on the liquid tube, use an adjustable wrench with a nominal
handle length of 200 mm.
Tube diameter
Tightening torque
(approximate)
Tube thickness
ø6.35 (1/4")
14 – 18 N •m
{140 – 180 kgf •cm}
0.8 mm
ø9.52 (3/8")
34 – 42 N •m
{340 – 420 kgf •cm}
0.8 mm
ø12.7 (1/2")
49 – 55 N •m
{490 – 550 kgf •cm}
0.8 mm
ø15.88 (5/8")
68 – 82 N •m
{680 – 820 kgf •cm}
1.0 mm
01_330918_EU_Eng.indb 85 2021/9/9 11:27:08
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