Lennox SL280UH090V36B Installation Instructions Manual page 22

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 after
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 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.)
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 26
Horizontal Applications
MANUAL
MAIN SHUT-OFF
VALVE
GROUND
JOINT
UNION
DRIP LEG
FIELD
PROVIDED
AND
INSTALLED
FIGURE 27
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.)..
MANUAL MAIN
SHUT-OFF VALVE
WILL NOT HOLD
NORMAL TEST
PRESSURE
1/8 NPT PLUG
Page 22
AUTOMATIC
GAS VALVE
Right Side Piping
Horizontal Application
Left-Side Air Discharge
MANUAL
MAIN SHUT-OFF
VALVE
GROUND
JOINT
UNION
DRIP LEG
IMPORTANT
ISOLATE
GAS VALVE
CAP
FIGURE 28
MANUAL
MAIN SHUT-OFF
VALVE
(With 1/8 in. NPT
Plugged Tap
Shown)
GROUND
JOINT
UNION
DRIP LEG
(Alternate)
FURNACE