Daikin VRV III Manual page 195

Installation
• Refer to Table 1 for tightening torque.
Table 1
Pipe
Tightening torque
size
φ 6.4
14.2 – 17.2 N·m
(1/4") (144 – 176 kgf·cm)
φ 9.5
32.7 – 39.9 N·m
(3/8") (333 – 407 kgf·cm)
φ 12.7
49.5 – 60.3 N·m
(1/2") (504 – 616 kgf·cm)
φ 15.9
61.8 – 75.4 N·m
(5/8") (630 – 770 kgf·cm)
CAUTION
Overtightening may damage the flare and cause leaks.
Be careful for oil not to adhere to any portions other
than a flare part. If oil adhere to resin parts etc., there is
a possibility of damaging by deterioration.
• 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.
(2) After the work is finished, make sure to check that
there is no gas leak.
(3) 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 insula-
tion 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 mid. 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
Insulation for fitting (4)
Piping insulation
(accessory)
material (main unit)
Flare nut connection
Attach to base
Turn seams up
Main unit
Clamp (9)
Piping insulation material
(accessory)
(Field supply)
6
190
Flare dimen-
Flare shape
sion A (mm)
8.7 – 9.1
12.8 – 13.2
R0.4-0.8
16.2 – 16.6
19.3 – 19.7
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
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 (CAUTION 2) while
feeding nitrogen into the refrigerant piping (CAUTION 1), and
finally connect the indoor unit using the flare connections.
(Refer to Fig. 9)
CAUTION
1. When brazing a pipe while feeding nitrogen inside the
pipe, make sure to set the nitrogen pressure to 0.02 MPa
2
(0.2 kg/cm ) using the pressure reducing valve. (This
pressure is such that breeze is blown to your cheek.)
2. Do not use a flux when brazing the refrigerant pipe joints.
Use phosphor copper brazer (BCuP-2: JIS Z 3264/B-
Cu93P-710/795: ISO 3677) which does not require flux.
(Using a flux containing chlorine may cause the piping to
corrode. Using a welding flux containing fluorine may
cause the refrigerant lubricant to deteriorate, and affect
adversely the refrigerant piping system.)
Pressure-reducing valve
Part to be brazed
Nitrogen
Refrigerant piping
Fig. 9
Not recommendable but in case of emergency
You must use a torque wrench but if you are obliged to install the
unit without a torque wrench, you may follow the installation
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 Further tightening angle
φ 6.4 (1/4")
60 to 90 degrees
φ 9.5 (3/8")
60 to 90 degrees
φ 12.7 (1/2")
30 to 60 degrees
φ 15.9 (5/8")
30 to 60 degrees
: http://splitoff.ru/tehn-doc.html
ED34-862
Taping
hands
valve
Nitrogen
Recommended arm
length of tool
Approx. 150mm
Approx. 200mm
Approx. 250mm
Approx. 300mm
English
3PN09042-1A
FXDQ-PB / FXDQ-NB