Piping Connection; Vacuum Drying - Lennox LT-B3021HW Installation Operating & Maintenance Manual

Piping Connection

1. Form the piping according to its routing. Avoid
bending and bending back the same piping point
more than three times. (This will result in hardening
of pipe.)
2. After deforming the piping, align centers of the
union fitting of the indoor unit and the piping, and
tighten them firmly with wrenches.
3. Connect pipe to the service valve or ball valve
which is located below the outdoor unit.
4. After completing the piping connection, be sure to
check if there is gas leakage in indoor and outdoor
connection.

Vacuum drying

After completing the piping connection, execute vacu-
um drying for the connecting piping and the indoor
unit.
The vacuum drying must be carried out using the ser-
vice ports of both the liquid and gas side valves.
Model Liquid side piping
24K, 28K, 30K BTU Ø 9.52mm
36K BTU Ø 9.52mm
CAUTION
Use two wrenches and tighten with regular torque.
Flare nut fastening torque
Ø6.35mm
Ø9.52mm
Ø12.7mm
Ø15.88mm
Ø19.05mm
Gas side piping
Ø15.88mm
Ø19.05mm
1.8kg . mm
4.0kg . mm
5.5kg . mm
6.6kg . mm
6.6kg . mm
Outdoor
unit
Flare connection
–30–
Liquid side
Indoor
unit
Flare connection
Gas side
Union