Concealed Duct High Static Pressure
Tightening connection
CAUTION
Do not apply excessive torque. Otherwise, the nut may crack depending on the conditions.
| (Unit: N•m) |
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Outer dia. of copper pipe | Tightening torque |
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12.7 mm (dia.) | 50 to 62 (5.0 to 6.2 kgf•m) |
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▼Tightening torque of flare pipe connections
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 and outdoor units of the specified tightening torque.
Incorrect connections may cause not only a gas leak, but also a trouble of the refrigeration cycle.
Align the centres 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.
Half union 
Flare nut
Externally |
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| Internally |
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threaded side |
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| threaded side |
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Use a wrench to secure. | Use a torque wrench to tighten. | |||
REQUIREMENT
Tightening with an excessive torque may crack the nut depending on installation conditions.
Tighten the nut within the specified tightening torque.
Installation Manual
•Remove the cup on the gas side piping by using a brazing machine.
CAUTION
Do not burn the pipe heat insulator.
Remove the cap.
Attached joint part
Connection pipe Locally procured Ø28.6 mm
•Braze the attached joint part to the gas side piping and braze the connection piping to the joint part.
brazing
Braze all around
brazing
•Turn back the pipe heat insulator and tie up with a banding band.
Tie up with a banding
band.
!Gas side refrigerant pipe connection
•Turn up the pipe heat insulator to the unit side.
•Wrap the pipe with wet cloth.
Piping with outdoor unit
•For details of installation, refer to the Installation Manual of the outdoor unit.
!Evacuation
Wet cloth
Turn up pipe heat insulator
Remove the all brazed part.
Using a vacuum pump, perform vacuuming from the charge port of valve of the outdoor unit.
For details, follow to the Installation Manual attached to the outdoor unit.
•Never use the refrigerant sealed in the outdoor unit for evacuation.
REQUIREMENT
For the tools such as charge hose, etc., use those manufactured exclusively for R410A.
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