Fujitsu AS*7A Technical Manual page 152

4. CONNECTING THE PIPING
1. FLARE PROCESSING
(1) Cut the connection pipe with pipe cutters so that the
pipe is not deformed.
(2) Holding the pipe downwards so that cuttings cannot
enter the pipe, remove the burrs.
(3) Remove the flare nut from the indoor unit pipe and
outdoor unit and assemble as shown in (Table 1)
and insert the flare nut onto the pipe, and flare with
a flaring tool.
(4) Check if the flared part "L" (Fig. 23) is spread uni-
formly and that there are no cracks.
Table 2
Pipe
Small pipe Small (width across flats 22 mm)
Large pipe Large (width across flats 24 mm)
Fig. 23
Width across flats
L
2. BENDING PIPES
The pipes are shaped by your hands. Be careful not to
collapse them.
Fig. 24
Extend the pipe
OK
by unwinding it.
Do not bend the pipes in an angle more than 90°.
When pipes are repeatedly bent or stretched, the
material will harden, making it difficult to bend or
stretch them any more. Do not bend or stretch the
pipes more than three times.
When bending the pipe, do not bend it as is. The pipe
will be collapsed. In this case, cut the heat insulating
pipe with a sharp cutter as shown in Fig. 25, and bend
it after exposing the pipe. After bending the pipe as
you want, be sure to put the heat insulating pipe back
on the pipe, and secure it with tape.
Fig. 25
Pipe
Heat insulating
pipe
Cutter
Cut line
Flare nut
L dimension
Small pipe
1 .8 to 2.0mm (9.53mm dia.)
Large pipe
2.2 to 2.4mm (15.88mm dia.)
NO
3. CONNECTION PIPES
(1) Indoor unit side
Centering the pipe against port on the indoor unit,
turn the flare nut with your hand (Fig. 26).
Be sure that the small pipe is completely installed
before connecting the large pipe.
Fig. 26
Optional parts
Be sure to apply the pipe against the
port on the indoor unit correctly. If the
centering is improper, the flare nut can-
not be tightened smoothly. If the flare
nut is forced to turn, the threads will be
damaged.
When the flare nut is tightened properly by your
hand, use a torque wrench to finally tighten it.
Fig. 27
Torque
wrench
Indoor unit
pipe
Table 3 : Flare nut tightening torque
Flare nut
Small pipe
9.52 mm dia.
Large pipe
15.88 mm dia.
Do not remove the cap from the connection pipe
before connecting the pipe.
Be sure to connect the large pipe after
connecting the small pipe completely.
– 151 – – –
Indoor unit side
Tighten with two wrenches.
Wrench (fixed)
Flare nut
To prevent gas leakage,
Connection pipe
coat the flare surface with
refrigerator oil.
Tightening torque
30.4 to 34.3 N
(310 to 350 kgf
73.6 to 78.5 N
(750 to 800 kgf
m
•
cm)
•
m
•
cm)
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