Hitachi Set Free mini-HNRQ1 Series, Service Manual

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20
INSTALLATION
(B) Joint Selection
The minimum thickness of joint and flare nut dimension are selected from the table below:
Minimum Thickness of Joint Flare Nut Dimension B
Unit: mm Unit: mm
Diameter(Φd) R410A Diameter(Φd) R410A
6.35 0.5 6.35 17
9.52 0.6 9.52 22
12.7 0.7 12.7 26
15.88 0.8 15.88 29
19.05 0.8 19.05 36
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 a little of refrigerant oil (field-supplied) on the flare surface of the pipe and flare nut before
performing flaring work. Tighten the flare nut to 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 oc -
curred after completing flaring work.
(E) Be sure to use two wrenches as shown.
Stop Valve
Flare Nut
Do not apply the two wrenches work here.
Refrigerant leakage shall occur
Use two wrenches as shown Tightening Work for Stop Valve
Required Tightening Torque
Pipe Diameter Tightening Torque
Φ6.35mm 20 N·m
Φ9.52mm 40 N·m
Φ12.7mm 60 N·m
Φ15.88mm 80 N·m
Φ19.05mm 100 N·m
Flare Nut
B
Apply Refrigerant Oil
Do not apply
refrigerant oil
to exterior flared
surfaces.