Gas Piping - International comfort products N8MXL Installation Instructions Manual

furnace casing as shown in Figure 20 and Figure 22. Bypass
humidifier may be attached into unused return air side of the
furnace casing. (See Figure 20 and Figure 22)
Not all horizontal furnaces are approved for side return air
connections. (See Figure 22)

GAS PIPING

WARNING
!
FIRE OR EXPLOSION HAZARD
Failure to follow this warning could result in personal
injury, death, and/or property damage.
Never purge a gas line into a combustion chamber.
Never test for gas leaks with an open flame. Use a
commercially available
specifically for the detection of leaks to check all
connections. A fire or explosion may result causing
property damage, personal injury or loss of life.
WARNING
!
FIRE OR EXPLOSION HAZARD
Failure to follow this warning could result in personal
injury,death, and/or property damage.
Use proper length of pipe to avoid stress on gas
control manifold and a gas leak.
CAUTION
!
FURNACE OVERHEAT HAZARD
Failure to follow this caution may result in property
damage.
Connect gas pipe to gas valve using a backup
wrench to avoid damaging gas controls and burner
misalignment.
WARNING
!
FIRE OR EXPLOSION HAZARD
Failure to follow this warning could result in personal
injury, death, and/or property damage.
If local codes allow the use of a flexible gas appliance
connector, always use a new listed connector. Do not
use a connector which has previously served another
gas appliance. Black iron pipe shall be installed at the
furnace gas control valve and extend a minimum of 2
in.(51 mm) outside the furnace.
Gas piping must be installed in accordance with national and
local codes. Refer to current edition of NFGC.
Installations must be made in accordance with all authorities
having jurisdiction. If possible, the gas supply line should be a
separate line running directly from meter to furnace.
NOTE: In the state of Massachusetts:
1. Gas supply connections MUST be performed by a li-
censed plumber or gas fitter.
2. When flexible connectors are used, the maximum
length shall not exceed 36 inches (915 mm).
3. When lever handle type manual equipment shutoff
valves are used, they shall be T−handle valves.
4. The use of copper tubing for gas piping is NOT ap-
proved by the state of Massachusetts.
16
soap solution made
Specifications are subject to change without notice.
Refer to Table 6 for recommended gas pipe sizing. Risers
must be used to connect to furnace and to meter. Support all
gas piping with appropriate straps, hangers, etc. Use a
minimum of 1 hanger every 6 ft. (2 M). Joint compound (pipe
dope) should be applied sparingly and only to male threads of
joints. Pipe dope must be resistant to the action of propane
gas.
An accessible manual equipment shutoff valve MUST be
installed external to furnace casing and within 6 ft. (2 M) of
furnace. A 1/8−in. (3 mm) NPT plugged tapping, accessible
for test gauge connection, MUST be installed immediately
upstream of gas supply connection to furnace and
downstream of manual equipment shutoff valve.
NOTE: The furnace gas control valve inlet pressure tap
connection is suitable to use as test gauge connection
providing test pressure DOES NOT exceed maximum 0.5
psig (14−in. w.c.) stated on gas control valve. (See Figure 41)
Some installations require gas entry on right side of furnace
(as viewed in upflow). (See Figure 18)
Install a sediment trap in riser leading to furnace as shown in
Figure 19. Connect a capped nipple into lower end of tee.
Capped nipple should extend below level of furnace gas
controls. Place a ground joint union between furnace gas
control valve and exterior manual equipment gas shutoff
valve. A 1/8−in. (3 mm) NPT plugged tapping, accessible for
test gauge connection, MUST be installed immediately
upstream of gas supply connection to furnace and
downstream of manual equipment shutoff valve.
Figure 18 − Burner and Manifold
2" (51mm)
Street Elbow
Figure 19 − Typical Gas Pipe Arrangement
GAS
SUPPLY
MANUAL
SHUTOFF
VALVE
(REQUIRED)
SEDIMENT
TRAP
UNION
A08551
A02035
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