Daikin FXDQ-M Engineering Data page 24

EDUS39-600-F2_a
than a flare part. If oil adheres to resin parts., deteriora-
tion can occur.
• Refer to Table 2 if no torque wrench is available.
Using a wrench to tighten flare nuts causes the tightening
torque to suddenly grow much tighter after a certain point.
From there, tighten the nut further by the appropriate angle
listed in Table 2.
(5) After the work is finished, ensure there is no gas leak.
(6) After checking for gas leaks, be sure to insulate the
pipe connections referring to Fig. 8.
• Insulate using the insulation for fitting (3) (4) included
with the liquid and gas pipes. Besides, make sure the
insulation for fitting (3) (4) on the liquid and gas piping
has its seams facing up.
Tighten both edges with clamp (9).
• For the gas piping, wrap the middle sealing pad (6) over
the insulation for fitting (4) flare nut part.
Liquid Piping Insulation Procedure
Piping insulation material
(main unit)
Attach to base
Main unit
Clamp (9) (accessory)
Gas Piping Insulation Procedure
Piping insulation
Insulation for fitting (4) (accessory)
material (main unit)
Flare nut connection
Attach to base
Turn seams up
Main unit
Clamp (9)
Piping insulation material
(accessory)
(Field supply)
CAUTION
Be sure to insulate any field piping all the way to the piping
connection inside the unit. Any exposed piping may cause
condensation or burns if touched.
• When brazing the refrigerant piping, perform nitrogen
replacement first, or perform the brazing while feeding
nitrogen into the refrigerant piping, and then connect the
indoor unit using the flare connections. (Refer to Fig. 9)
CAUTION
• When brazing a pipe while feeding nitrogen inside the pipe,
make sure to set the nitrogen pressure to 29 psi or less
using the pressure reducing valve.
FXDQ-M
Insulation for fitting (3) (accessory)
Flare nut connection
Turn seams up
Piping insulation material
(Field supply)
Liquid pipe
Gas pipe
Mid. sealing pad (6) (accessory)
Wrap over the top of
the flare nut connection.
Fig. 8
Part to be brazed Taping
Nitrogen
Refrigerant piping
Not recommendable but in case of emergency
You must use a torque wrench but if it is necessary to install
the unit without a torque wrench, you may follow the installa-
tion method mentioned below.
After the work is finished, make sure to check that there is
no gas leak.
When you keep on tightening the flare nut with a spanner,
there is a point where the tightening torque suddenly
increases. From that position, further tighten the flare nut the
angle shown below:
Table 2
Pipe size (in.) Further tightening angle
φ1/4
60 to 90 degrees
φ3/8
60 to 90 degrees
φ1/2
30 to 60 degrees
φ5/8
30 to 60 degrees
DANGER
• Use of oxygen could result in an explosion resulting in seri-
ous 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.
NOTE
• Do not use flux when brazing refrigerant piping. Therefore,
use the phosphor copper brazing filler 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. Flux containing fluorine will damage
refrigerant oil.)
Installation
Pressure-reducing valve
hands
Nitrogen
valve
Fig. 9
Recommended arm
length of tool (in.)
Approx. 5-7/8
Approx. 7-7/8
Approx. 9-13/16
Approx. 11-13/16
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