Toshiba R410A Service Manual page 25

Tightening of Connecting Part
Outer dia. of copper pipe
6.4 mm (diam.)
9.5 mm (diam.)
12.7 mm (diam.)
15.9 mm (diam.)
• Align the centers of the connecting pipes and tighten
the flare nut strong as far as possible with your
fingers.
Then fix the nut with a spanner and tighten it with
torque wrench as shown in the figure.
Half union or packed valve
Externally
threaded side
Fix with spanner.
• As shown in the figure, be sure to use a double
spanner to loosen or tighten the flare nut of the valve
at gas side. If using a single spanner, the nut cannot
be tightened with necessary tightening torque.
On the contrary, use a single spanner to loosen or
tighten the flare nut of the valve at liquid side.
Cap
Loosened
Valve at gas side
(Unit: N•m)
Tightening torque
14 to 18 (1.4 to 1.8 kgf•m)
33 to 42 (3.3 to 4.2 kgf•m)
50 to 62 (5.0 to 6.2 kgf•m)
63 to 77 (6.3 to 7.7 kgf•m)
Flare at
indoor unit side
Flare at
outdoor unit side
Flare nut
Internally
threaded side
Tighten with torque wrench.
Cover
Piping valve
Tightened
Flare nut
REQUIREMENT
1. Do not put the spanner on the cap. The valve
may be broken.
2. If applying excessive torque, the nut may be
broken according to some installation conditions.
• After the installation work, be sure to check gas leak
of connecting part of the pipes with nitrogen.
• Pressure of R410A is higher than that of R22
(Approx. 1.6 times). Therefore, using a torque
wrench, tighten the flare pipe connecting sections
which connect the indoor/outdoor units at the speci-
fied tightening torque. Incomplete connections may
cause not only a gas leak, but also a trouble of the
refrigeration cycle.
Do not apply refrigerating machine oil to
the flared surface.
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Cover