Hitachi RAS-3.0HNSKQ Original Instruction page 30

(B) Flare Nut Dimension
The minimum thickness of joint and flare nut dimension are selected from
the table below:
Minimum Thickness of Joint
Diameter(Φd)
6.35
9.53
12.7
15.88
19.05
NOTE:
 Do not use a thin joint other than the ones shown in the table above.
(C) Verify that there are no scratches, metal particles, gaps, or deformations at the flared end before
making connections to the system.
(D) Apply refrigerant oil (field-supplied) slightly on the flare surface of the pipe and flare nut before
performing flaring work. Tighten the flare nut with the specified torque settings using two wrenches.
Perform flaring work to the liquid piping side before treating the gas piping side. Verify that no gas leakage
has occurred after completing flaring work.
(E) Be sure to use two wrenches as shown.
Use two wrenches as shown
Pipe Diameter (mm)
Unit: mm
R410A
0.5
0.6
0.7
0.8
0.8
Required Tightening Torque for Flare Nut
Φ6.35
Φ9.53
Φ12.7
Φ15.88
Φ19.05
Flare Nut Dimension B
Unit: mm
Diameter(Φd) R410A
6.35 17
9.53 22
12.7 26
15.88 29
19.05 36
Tightening work for stop valve
Tightening Torque
20 N·m
40 N·m
60 N·m
80 N·m
100 N·m
21