Refrigerant Piping Work; Flaring The Pipe End; Refrigerant Piping - Daikin R410A Split Series Installation Manual

Refrigerant Piping Work

Refer also to the installation manual for the outdoor unit.
WARNING
• Do not apply mineral oil on flared part.
• Prevent mineral oil from getting into the system as this would reduce the service life of the units.
• Never use piping which has been used for previous installations. Only use parts which are delivered with the unit.
• Never install a dryer to this R410A unit in order to guarantee its service life.
• The drying material may dissolve and damage the system.
• Incomplete flaring may result in refrigerant gas leakage.
Execute thermal insulation work completely on both sides of the gas and the liquid piping. Otherwise, a water leakage can
result sometimes.
For gas piping, use insulation material of which heat resistant temperature is not less than 230°F (110°C).
Also, in cases where the temperature and humidity of the refrigerant piping sections might exceed 86°F (30°C) or RH80%,
reinforce the refrigerant insulation. (13/16 inch (20mm) or thicker) Condensation may form on the surface of the insulating
material.
Before refrigerant piping work, check which type of refrigerant is used. Proper operation is not possible if the types of
refrigerant are not the same.
1.

Flaring the pipe end

1) Cut the pipe end with a pipe cutter.
2) Remove burrs with the cut surface facing downward,
so that the filings do not enter the pipe.
Cut exactly at
right angles.
3) Put the flare nut on the pipe.
4) Flare the pipe.
5) Check that the flaring has been done correctly.
2.

Refrigerant piping

CAUTION
• Use the flare nut fixed to the main unit. (This is to prevent the flare nut from cracking as a result of deterioration over time.)
• To prevent gas leakage, apply refrigeration oil only to the inner surface of the flare. (Use refrigeration oil for R410A.)
• Use a torque wrench when tightening the flare nuts to prevent damage to the flare nuts and gas leakage.
• Do not have oil adhere to the screw fixing part of resin parts.
If oil adheres, it may weaken the strength of screwed part.
• Align the centers of both flares and tighten the flare nuts 3 or 4 turns by hand, then tighten them fully with a spanner and
a torque wrench.
Do not apply refrigeration
oil to the outer surface.
Flare nut
Do not apply refrigeration oil to
the flare nut to avoid tightening
with excessive torque.
O.D. 3/8 inch (9.5mm)
Gas side O.D. 1/2 inch (12.7mm)
O.D. 5/8 inch (15.9mm)
Liquid side O.D. 1/4 inch (6.4mm)
■
English
Remove burrs.
Apply oil
Piping size Flare nut tightening torque
24-1/8–29-1/2Ibf • ft (32.7-39.9N • m)
36-1/2–44-1/2Ibf • ft (49.5-60.3N • m)
45.6–55.6lbf • ft (61.8-75.4N • m)
10-1/2–12-3/4Ibf • ft (14.2-17.2N • m)
Set exactly at the position shown below.
Flare tool for
A
R32 or R410A
Clutch-type
0-0.020 inch
Die
A
(0-0.5mm)
The flare's inner surface must be
flaw-free.
When flaring, do not over-tighten
and crack.
Apply refrigeration
Torque wrench
oil only to the inner
surface of the flare.
Spanner
Piping union
Flaring
Conventional flare tool
Clutch-type Wing-nut type
(Rigid-type) (Imperial-type)
0.039-0.059 inch 0.059-0.079 inch
(1.0-1.5mm) (1.5-2.0mm)
Check
The pipe end must be evenly flared
in a perfect circle.
Make sure that the flare nut is fitted.
Tighten
Flare nut
16