Lennox SL280UHNV Installation Instructions Manual page 20

MANUAL
MAIN SHUT-OFF
VALVE
(With 1/8 in. NPT
Plugged Tap Shown)
GROUND
JOINT
UNION
DRIP LEG
MANUAL
MAIN SHUT-OFF
VALVE
GROUND
JOINT
UNION
DRIP LEG
Horizontal Application
Right-Side Air Discharge
Leak Check
After gas piping is completed, carefully check all field-in-
stalled piping connections for gas leaks. Use a commer-
cially available leak detecting solution specifically manu-
factured for leak detection. Never use an open flame to
test for gas leaks.
The furnace must be isolated from the gas supply system
by closing the individual manual shut-off valve during any
gas supply system at pressures greater than or equal to ½
psig. (3.48 kPa, 14 inches w.c.). This furnace and its com-
ponents are designed, manufactured and independent-
ly certified to comply with all applicable ANSI/CSA stan-
dards. A leak check of the furnace and its components is
not required.
IMPORTANT
When testing pressure of gas lines, gas valve must be
disconnected and isolated. See figure 28. Gas valves
can be damaged if subjected to pressures greater than
1/2 psig (3.48 kPa, 14 inches w.c.)..
Left Side Piping
(Standard)
AUTOMATIC
GAS VALVE
NOTE - BLACK IRON PIPE ONLY TO BE ROUTED INSIDE OF CABINET
Possible Gas Piping Configurations
NOTE - BLACK IRON PIPE ONLY TO BE ROUTED INSIDE OF CABINET
FIELD
PROVIDED
AND INSTALLED
FIgURE 18
Horizontal Applications
MANUAL
MAIN SHUT-OFF
VALVE
GROUND
JOINT
UNION
DRIP LEG
FIELD
PROVIDED
AND
INSTALLED
FIgURE 19
Some soaps used for leak detection are corrosive to
certain metals. Carefully rinse piping thoroughly after
leak test has been completed. Do not use matches,
candles, flame or other sources of ignition to check for
gas leaks.
MANUAL MAIN
SHUT-OFF VALVE
WILL NOT HOLD
NORMAL TEST
PRESSURE
1/8 NPT PLUG
Page 20
AUTOMATIC
GAS VALVE
Right Side Piping
Horizontal Application
Left-Side Air Discharge
MANUAL
MAIN SHUT-OFF
VALVE
GROUND
JOINT
UNION
DRIP LEG
CAUTION
ISOLATE
GAS VALVE
CAP
FIgURE 20
MANUAL
MAIN SHUT-OFF
VALVE
(With 1/8 in. NPT
Plugged Tap
Shown)
GROUND
JOINT
UNION
DRIP LEG
(Alternate)
FURNACE