Lennox SIGNATURE SL280UHV Installation Instructions Manual page 24

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 piping
connections (factory− and field−installed) for gas leaks. Use
a leak detecting solution or other preferred means.
NOTE − If emergency shutoff is necessary, shut off the main
manual gas valve and disconnect the main power to the
furnace. The installer should properly label these devices.
CAUTION
Some soaps used for leak detection are corrosive to
certain metals. Carefully rinse piping thoroughly af-
ter leak test has been completed. Do not use
matches, candles, flame or other sources of ignition
to check for gas leaks.
The furnace must be isolated by closing its individual
manual shut-off valve and disconnecting from from the gas
Left Side Piping
(Standard)
AUTOMATIC
GAS VALVE
NOTE − BLACK IRON PIPE ONLY TO BE ROUTED INSIDE OF CABINET
Horizontal Applications
Possible Gas Piping Configurations
NOTE − BLACK IRON PIPE ONLY TO BE ROUTED INSIDE OF CABINET
AUTOMATIC
GAS VALVE
FIELD
PROVIDED
AND INSTALLED
FIGURE 25
MANUAL
MAIN SHUT−OFF
VALVE
GROUND
JOINT
UNION
DRIP LEG
FIELD
PROVIDED
AND
INSTALLED
FIGURE 26
supply system the during any pressure testing of the gas
supply system at pressures less than or equal to 1/2 psig
(3.48 kPa, 14 inches w.c.).
When testing pressure of gas lines, gas valve must
be disconnected and isolated. See figure 27. Gas
valves can be damaged if subjected to pressures
greater than 1/2 psig (3.48 kPa, 14 inches w.c.).
MANUAL MAIN
SHUT−OFF VALVE
WILL NOT HOLD
NORMAL TEST
PRESSURE
1/8 NPT PLUG
Page 24
MANUAL
MAIN SHUT−OFF
VALVE
(With 1/8 in. NPT
Plugged Tap
Shown)
GROUND
JOINT
UNION
DRIP LEG
Right Side Piping
(Alternate)
Horizontal Application
Left−Side Air Discharge
MANUAL
MAIN SHUT−OFF
VALVE
GROUND
JOINT
UNION
DRIP LEG
IMPORTANT
ISOLATE
GAS VALVE
CAP
FIGURE 27
FURNACE