−
38
−
90°
Roughness Warp
Obliquity
A
Die
Pipe
•
Tightening torque of flare pipe connections
The operating pressure of R410A is higher than that of
R22. (Approx. 1.6 times). It is therefore necessary to
firmly tighten the flare pipe connecting sections (which
connect the indoor and outdoor units) up to the
specified tightening torque. Incorrect connections may
cause not only a gas leakage, but also damage to the
refrigerant cycle.
CAUTION
•
KEEP IMPORTANT 5 POINTS FOR PIPING WORK
(1)
Take away dust and moisture (Inside of the
connecting pipes.)
(2)
Tight connection (between pipes and unit)
(3)
Evacuate the air in the connecting pipes using
VACUUM PUMP.
(4)
Check gas leak (connected points)
∅
6.35 16 to 18 (1.6 to 1.8 kgf·m)
Outer dia.
of copper pipe
R410A
tool used
Conventional
tool used
6.35 0 to 0.5 1.0 to 1.5
9.52 0 to 0.5 1.0 to 1.5
12.7 0 to 0.5 1.0 to 1.5
Outer dia.
of copper pipe
R410A
6.35 1.5 to 2.0
9.52 1.5 to 2.0
12.7 2.0 to 2.5
8-5-2. Refrigerant piping connection
1. Cut the pipe with a pipe cutter.
Fig. 8-5-2
2.
Insert a flare nut into the pipe, and flare the pipe.
•
Projection margin in flaring : A (Unit : mm)
Fig. 8-5-3
<Tightening connection>
Align the centers of the connecting pipes and tighten
the flare nut as far as possible with your fingers. Then
tighten the nut with a spanner and torque wrench as
shown in the figure.
CAUTION
•
Do not apply excess torque.
•
Otherwise, the nut may crack depending on the
conditions.
∅
9.52 30 to 42 (3.0 to 4.2 kgf·m)
Rigid (Clutch type)
Imperial (wing nut type, conventional tool)
∅
12.7 50 to 62 (5.0 to 6.2 kgf·m)
Outer dia.
of copper pipe
Tightening torque
(Unit : N·m)
(5) Be sure to fully open the packed valves before
Fig. 8-5-6
Flare nut
Half union
Externally
threaded side
Flare at indoor unit side
Flare at outdoor unit side
Mark line
Use a wrench to secure.
Use a torque wrench to tighten.
Internally
threaded side
Fig. 8-5-4
Fig. 8-5-5
operation.
FILE NO. SVM-10036