See the following table for tightening torque.
(Applying too much torque may cause the flares to crack.)
After all the piping has been connected, use nitrogen to perform
a gas leak check.
Tightening
Pipe size
Torque (N•m)
Ø9.5
32.7~39.9
Ø12.7
49.5~60.3
Ø15.9
61.8~75.4
NOTE
You must use a torque wrench but if you are obliged to
install the unit without a torque wrench, you may follow
the installation method mentioned below.
After the work is finished, make sure to check that
there is no gas leak.
When you keep on tightening the flare nut with a
spanner, there is a point where the tightening torque
suddenly increases. From that position, further tighten
the flare nut within the angle shown below:
Further tightening
Pipe size
Ø9.5 (3/8")
Ø12.7 (1/2")
Ø15.9 (5/8")
Precautions when selecting branch piping
If the overall equivalent piping length is ≥90 m, be sure to enlarge the
pipe diameter of the liquid-side and gas-side main piping. (This does
not apply to U-5MX3 type)
Gas side
U-5MX3
Ø15.9
U-8MX3
Ø19.1
U-10MX3
Ø22.2
U-12+14MX3
Ø28.6
U-16~22MX3
Ø28.6
U-24MX3
Ø34.9
U-26~34MX3
Ø34.9
U-36~48MX3
Ø41.3
Liquid side
U-5MX3
Ø9.5
U-8+10MX3
Ø9.5
U-12~16MX3
Ø12.7
U-18~24MX3
Ø15.9
U-26~48MX3
Ø19.1
If the recommended pipe size is not available, stick to the original
pipe diameter (which may result in a small capacity decrease).
U-5~48MX3XPQB
Urban Multi air conditioner
4PW21867-1A
A (mm)
Flare shape
90 ±2
12.8~13.2
A
16.2~16.6
R=0.4~0.8
19.3~19.7
Recommended
angle
arm length of tool
60~90°
±200 mm
30~60°
±250 mm
30~60°
±300 mm
Ø19.1
Ø22.2
Ø25.4
Not Increased
Ø31.8
Not Increased
Ø38.1
Not Increased
Not Increased
Ø12.7
Ø15.9
Ø19.1
Ø22.2
Cautions for installation of multiple outdoor units
1.
The piping between the outdoor units must be routed level or slightly
upward to avoid the risk of oil detention into the piping side.
Pattern 1
1
2
1
To indoor unit
2
Piping between outdoor units
Pattern 2
1
1
To indoor unit
Prohibited pattern: Change to Pattern 1 or 2
1
1
To indoor unit
2.
To avoid the risk of oil retention to the stopping unit side, always
connect the stop valve and the piping between outdoor units as
shown in the figure A or figure B.
A
B
Prohibited pattern
1
2
2
2
1
2
2
2
Oil remains in the outdoor unit that stops.
Change to pattern 1 or 2
A
B
C
1
3
Oil remains in the outdoor unit C when the system stops.
1
2
1
1
A
B
A
B
C
1
3
Installation manual
6