9
Outside
Diameter
Recommended
Torque
No torque wrench
available
Finger tighten and
use an appropriately
sized wrench to turn an
additional:
Inches
U.S.
1/4”
15 ft.-lb.
1/4 turn
3/8”
26 ft.-lb.
1/2 turn
1/2”
41 ft.-lb.
7/8 turn
5/8”
48 ft.-lb.
1 full turn
Table 3. Flare Nut Torque Recommendations
IMPORTANT!
Flared connections should always be accessi-
ble and must be insulated to prevent condensa-
tion. See Figure 7.
MS Box
Insulate ALL flared connections
to prevent condensation.
Figure 7. Insulate Flared Connections
Table 4. Piping Connection Information
Indoor Unit
Capacity BTUs
Indoor Unit
Factory Flare
Connection
Sizes Gas/Liquid
Piping Length
From MS Box
to Indoor Unit Is
equal to or less
than 32 ft.
Adaptor
Required for
Connection to
MS Box
Piping Length
from MS Box to
Indoor Unit is
greater than 32
ft.
Adaptor
Required for
Connection to
MS Box
7,000
1/2 x 1/4
1/2 x 1/4
Yes -Factory
Supplied
5/8 x 3/8
No
9,000
1/2 x 1/4
1/2 x 1/4
Yes -Factory
Supplied
5/8 x 3/8
No
12,000
1/2 x 1/4
1/2 x 1/4
Yes -Factory
Supplied
5/8 x 3/8
No
15,000
1/2 x 1/4
1/2 x 1/4
Yes -Factory
Supplied
5/8 x 3/8
No
18,000
5/8 x 3/8
5/8 x 3/8
No
3/4 x 1/2
Yes -Field
Supplied
24,000
5/8 x 3/8
5/8 x 3/8
No
3/4 x 1/2
Yes -Field
Supplied
30,000
5/8 x 3/8
5/8 x 3/8
No
3/4 x 1/2
Yes -Field
Supplied
36,000
5/8 x 3/8
5/8 x 3/8
No
3/4 x 1/2
Yes -Field
Supplied
48,000
5/8 x 3/8
5/8 x 3/8
No
3/4 x 1/2
Yes -Field
Supplied
54,000
5/8 x 3/8
5/8 x 3/8
No
3/4 x 1/2
Yes -Field
Supplied
Flare nuts may need further tightening. Check ALL system
fl
are nut connections during pressure testing process.
NOTE - For VHIA072/096 indoor units, refer to the VHIA
installation manual and system piping diagram for correct
pipe sizes.
NOTE - All VVCA units have brazed connections. Piping
length rules still apply.
IMPORTANT
It is imperative that the system piping is installed per the
LVSS (Lennox VRF Selection Software) piping report! If
the measurements on the Lennox VRF piping diagram
do not match the anticipated
fi
eld measurements, contact
Lennox VRF Application Support before beginning piping
installation.