Connect Gas Piping - Lennox KGC092 Installation Instructions Manual

Connect Gas Piping (Gas Units)
Before connecting field-provided piping, check with gas
company or authorities having jurisdiction for local code
requirements. When installing gas supply piping, length
of run from gas meter must be considered in determining
pipe size for 0.5" w.c. (.12kPa) maximum pressure drop.
Do not use supply pipe smaller than unit gas connection.
For natural gas units, operating pressure at the unit gas
connection must be a minimum of 4.7" w.c. (1.19kPa)
and a maximum of 10.5" (2.60kPa) w.c. For LP/propane
gas units, operating pressure at the unit gas connection
must be a minimum of 11" w.c. (2.74kPa) and a maximum
of 13.0" w.c. (3.23kPa).
When making piping connections a drip leg should be
installed on vertical pipe runs to serve as a trap for
sediment or condensate. A 1/8" N.P.T. plugged tap is
located on gas valve for test gauge connection. Refer to
Heating Start-Up section for tap location. Install a ground
joint union between the gas control manifold and the main
manual shut-off valve. See figure 8 for gas supply piping
entering outside the unit. Figure 9 shows bottom gas entry
piping through the curb. Figure 10 shows bottom gas
entry piping through the unit.
Compounds used on threaded joints of gas piping shall be
resistant to the action of liquified petroleum gases.
OUTSIDE OF UNIT GAS PIPE CONNECTION
GROUND
JOINT UNION
TO GAS
SUPPLY
GAS PIPING
SUPPORT
MANUAL MAIN
SHUT-OFF VALVE
FIGURE 8
TO GAS
VALVE
DRIP LEG
(REFER TO
LOCAL CODES)
Page 8
BOTTOM ENTRY GAS PIPING
THROUGH THE CURB
MULLION BETWEEN
HEAT AND COMPRES­
SOR SECTIONS
4" NIPPLE
GROMMET
ALL ELBOWS ARE 3/4"
MANUAL MAIN
SHUT-OFF VALVE
TO GAS
SUPPLY
10" NIPPLE
ROOF
MOUNTING
FRAME
FIGURE 9
BOTTOM GAS ENTRY
THROUGH THE UNIT
ALL ELBOWS ARE 3/4"
GROMMET
10" NIPPLE
7-1/2" NIPPLE
GROMMET
7" TO GAS
NIPPLE
SUPPLY
ALTERNATE
KNOCKOUTS
ROOF MOUNTING
FRAME
DRIP LEG
FIGURE 10
4" NIPPLE
TO GAS
VALVE
5" NIPPLE
7-1/2" NIPPLE
GROUND
JOINT UNION
4" NIPPLE
3-1/2" NIPPLE
3" NIPPLE
DRIP LEG
MULLION BETWEEN
HEAT AND COMPRES­
SOR SECTIONS
5" NIPPLE
4" NIPPLE
4" NIPPLE
TO GAS
VALVE
GROUND
JOINT UNION
4" NIPPLE
MANUAL MAIN
SHUT-OFF VALVE
3-1/2" NIPPLE
3" NIPPLE