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Installation
• When connecting the flare nut, coat the flare section (both
inside and outside) with ester oil or ether oil, rotate three or
four times first, then screw in.
• Refer to the Table 2 for tightening torque.
• After inspecting pipe joints for gas leakage, be sure to insu-
late with the accessory joint insulation for fitting (3) (4) while
referring to the figure below. Fasten both ends with clamps
(6).
Wrap only the gas line side with the sealing pad (5). Bend
the pad over the insulation for fitting (union) from above.
Ester oil or ether oil.
Torque wrench
Spanner
Piping union
Flare nut
Insulation for fitting
(accessory) (3)
(For gas pipe)
Clamp (6)
(accessory)
Gas pipe
Sealing pad (accessory) (5)
(Wrapped over union)
Fig. 1
Use Table 3 as a reference if a torque wrench is not available.
Once work is complete, make sure there is no gas leaking. As
the flare nut is tightened with the wrench, the torque suddenly
increases. From that position, tighten the nut to the angle
shown on Table 3 .
• Make absolutely sure to execute heat insulation works on
the pipe-connecting section after checking gas leakage by
thoroughly studying the following figure and using the
attached heat insulating materials for fitting (3) and (4).
(Fasten both ends with the clamps (6) (accessory).) (Refer
to Fig. 1)
CAUTION
• Be sure to insulate any field piping all the way to the piping
connection inside the unit. Any exposed piping may cause
condensate or burns if touched.
21
Insulation for fitting
(accessory) (4)
(For liquid pipe)
Liquid pipe
• CAUTION TO BE TAKEN WHEN BRAZING REFRIGER-
ANT PIPING
Do not use flux when brazing refrigerant piping. Therefore,
use the phosphor copper brazing filter metal (BCuP) which
does not require flux.
Flux has an extremely negative effect on refrigerant piping
systems. For instance, if chlorine based flux is used, it will
cause pipe corrosion. If the flux contains fluorine, it will
damage the refrigerant oil.
DANGER
• Use of oxygen may cause an explosion resulting in serious
injury or death. Only use nitrogen gas.
• Refrigerant gas may produce toxic gas if it comes in contact
with fire such as from a fan heater, stove or cooking device.
Exposure to this gas could cause severe injury or death.
• Before brazing local refrigerant piping, nitrogen gas shall
be blown through the piping to expel air from the piping.
If brazing is done without nitrogen gas blowing, a large
amount of oxide film develops inside the piping, and could
cause system malfunction.
• When brazing the refrigerant piping, only begin brazing
after having carried out nitrogen substitution or while
inserting nitrogen into the refrigerant piping. Once this is
done, connect the indoor unit with a flared or a flanged con-
nection.
• Nitrogen should be set to 2.9 psi with a pressure-reducing
valve if brazing while inserting nitrogen into the piping.
Refrigerant
piping
Part to be
brazed
Nitrogen
NOTE
Use the flare nuts attached with the unit. Not recom-
mended but if no torque wrench is available, refer
to table 2 for tightening torque:
Table 2
Tightening
Flare
Pipe
torque
dimensions
size
(ft-lbf)
A (in.)
φ 1/4"
10.5 – 12.7
0.343 – 0.358
φ 3/8"
24.1 – 29.4
0.504 – 0.520
φ 1/2"
36.5 – 44.5
0.638 – 0.654
φ 5/8"
45.6 – 55.6
0.760 – 0.776
EDUS39-600-F7
Pressure-
reducing
valve
Taping
hands valve
Nitrogen
Flare shape (in.)
R 0.016 ~ 0.031
FXLQ-M / FXNQ-M
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