Refrigerant Piping - Toshiba MCY-MAP0401HT Installation Manual

5

Refrigerant piping

WARNING
• If the refrigerant gas leaks during installation work, ventilate the room immediately.
If the leaked refrigerant gas comes into contact with a source of fire, noxious gas maybe generated.
• After installation work is complete, check refrigerant gas does not leak.
If the refrigerant leaks into the room and comes into contact with a naked flame, noxious gas maybe generated.
Pipe forming / End positioning
◆ Flaring
1. Cut the pipe with a pipe cutter.
OK NO GOOD
90° Obliquity Roughness
2. Insert a flare nut into the pipe, and flare the pipe.
As the flaring sizes of R410A differ from those of
refrigerant R22, the flare tools newly manufactured
for R410A are recommended.
However, the conventional tools can be used by
adjusting projection margin of the copper pipe.
13-EN
• Flaring size : A (Unit : mm)
Warp
Outer dia. of copper pipe
R410A
9.5 13.2
15.9 19.7
* In case of flaring for R410A with the conventional
flare tool, pull it out approx. 0.5 mm more than that of
R22 to adjust to the specified flare size.
The copper pipe gauge is useful for adjusting
projection margin size.
• Projection margin in flaring :
B (Unit : mm)
Rigid (Clutch type)
Outer dia. R410A tool used Conventional tool used
of copper
R410A R22 R410A
pipe
9.5 0 to 0.5 (Same as left) 1.0 to 1.5 0.5 to 1.0
15.9 0 to 0.5 (Same as left) 1.0 to 1.5 0.5 to 1.0
Imperial (Wing nut type)
Outer dia. of copper pipe R410A
9.5 1.5 to 2.0
15.9 2.0 to 2.5
– 7 –
Tightening of connecting part
Outer dia. of copper pipe
9.5 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
A
Externally
threaded side
Fix with spanner.
+0
A
-0.4
R22
• As shown in the figure, be sure to use a double
13.0
spanner to loosen or tighten the flare nut of the valve
19.4
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.
B
Cap
Loosened
R22
Valve at gas side
R22
1.0 to 1.5
1.5 to 2.0
REQUIREMENT
1. Do not put the spanner on the cap. The valve may
(Unit: N•m)
be broken.
Tightening torque
2. If applying excessive torque, the nut may be broken
33 to 42 (3.3 to 4.2 kgf•m)
according to some installation conditions.
63 to 77 (6.3 to 7.7 kgf•m)
• After the installation work, be sure to check gas leak
of connecting part of the pipes with nitrogen.
Flare nut
Internally
threaded side
Tighten with torque wrench.
• Pressure of R410A is higher than that of R22
(Approx. 1.6 times). Therefore, using a torque
wrench, tighten the flare pipe connecting sections
Cover
which connect the indoor / outdoor units at the
specified tightening torque. Incomplete connections
may cause not only a gas leak, but also a trouble of
the refrigeration cycle.
Piping valve
Do not apply refrigerating machine oil to the
flared surface.
Tightened
Flare nut
NO GOOD
Cover
14-EN