Gas Piping - International comfort products F8MVL Installation Instructions Manual

Return Air Connections
WARNING
!
FIRE HAZARD
A failure to follow this warning could cause personal
injury, death and/or property damage.
Never connect return−air ducts to the back of the
furnace. Follow instructions below.
Downflow Furnaces
The return−air duct must be connected to return−air opening
(bottom inlet) as shown in Figure 1. DO NOT cut into casing
sides (left or right). Side opening is permitted for only upflow
and certain horizontal
connections should be made at ductwork or coil casing sides
exterior to furnace. (See Figure 19)
Upflow and Horizontal Furnaces
The return−air duct must be connected to bottom, sides (left or
right), or a combination of bottom and side(s) of main furnace
casing as shown in Figure 1. Bypass humidifier may be
attached into unused return air side of the furnace casing.
(See Figure 18 and Figure 20) Not all horizontal furnace
models are approved for side return air connections. (See
Figure 20)

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 soap solution made 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.
WARNING
!
FIRE OR EXPLOSION HAZARD
Failure to follow this warning could result in personal
injury, death, and/or property damage.
Gas valve inlet and/or inlet pipe must remain capped
until gas supply line is permanently installed to protect
the valve from moisture and debris. Also, install a
sediment trap in the gas supply piping at the inlet to
the gas valve.
Gas piping must be installed in accordance with national and
local codes. Refer to current edition of NFGC in the U.S.
441 01 2122 01
furnaces. Bypass humidifier
Specifications are subject to change without notice.
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 in. (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 approved
by the state of Massachusetts.
Refer to Table 5 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. (1.8 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.
Table 5 – Maximum Capacity of Pipe*
NOMINAL
INTERNAL
IRON
DIA.
PIPE SIZE
10
IN. (MM)
IN. (MM)
(3.0)
1/2 (12.7)
0.622 (158) 175
3/4 (19.0)
0.824 (20.9) 360
1 ( 25.4)
1.049 (26.6) 680
1-1/4
1.380 (35.0) 1400
(31.8)
1-1/2
1.610 (40.9) 2100
(38.1)
* Cubic ft of gas per hr for gas pressures of 0.5 psig (14-In. W.C.) or less and
a pressure drop of 0.5-In. W.C. (based on a 0.60 specific gravity gas). Ref: Table 6
and 9.2 NFGC.
WARNING
!
FIRE OR EXPLOSION HAZARD
A 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.
CAUTION
!
FURNACE DAMAGE HAZARD
Failure to follow this caution may result in furnace
damage.
Connect gas pipe to furnace using a backup wrench
to avoid damaging gas
misalignment.
An accessible manual equipment shutoff valve MUST be
installed external to furnace casing and within 6 ft. (1.8 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
downstream of manual equipment shutoff valve.
LENGTH OF PIPE − FT (M)
20 30 40 50
(6.0) (9.1) (12.1) (15.2)
120 97 82 73
250 200 170 151
465 375 320 285
950 770 660 580
1460 1180 990 900
controls and burner
connection to furnace and
17