Design and Technical Manual

6. SYSTEM DESIGN
SEPARATION TUBE3-2.
PIPE CONNECTION

CAUTION
Be sure to apply the pipe against the port on the indoor unit correctly. If the centering is improper, ●
the flare nut cannot be tighten smoothly. If the flare nut is forced to turn, the threads will be
damaged.
Do not remove the flare nut from the indoor unit pipe until immediately before connecting the ●
connection pipe.
Hold the torque wrench at its grip, keeping it in the right angle with the pipe, in order to tighten the ●
flare nut correctly.
Tighten the flare nuts with a torque wrench using the specified tightening method. Otherwise, ●
the flare nuts could break after a prolonged period, causing refrigerant to leak and generate a
hazardous gas if the refrigerant comes into contact with a flame.
When the are nut is tightened properly by your hand, hold the body side coupling with a separate
spanner, then tighten with a torque wrench. (See the table below for the are nut tightening torques.)
Flare nut
[in. (mm)]
Tightening torque
[lbf· ft (N·m)]
1/4 (6.35) 11.8 to 13.3 (16 to 18)
3/8 (9.52) 23.6 to 31.0 (32 to 42)
1/2 (12.70) 36.1 to 45.0 (49 to 61)
5/8 (15.88) 46.5 to 55.3 (63 to 75)
3/4 (19.05) 66.4 to 81.1 (90 to 110)
Type of separation tube
z
Name and shape
Liquid pipe Gas pipe
Positioning of separation tube
z
CAUTION
If it is placed horizontally, keep it within ± 15°. Otherwise, it will not separate the refrigerant evenly, ●
causing a reduction in performance.
Place the separation tube in a horizontal position as far as possible. Only place the separation ●
tube as shown below during unavoidable circumstances.
A
B
A
B
A
B
±15°
Horizontal
OK
A: Outdoor unit or Separation tube
B: Branch box or Separation tube
OK OK
Not good Not good
Horizontal
line
Vertical
or
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SYSTEM DESIGN SYSTEM DESIGN