-- 26 --
WASHABLE
FILTER
FILTER
SUPPORT
FILTER
RETAINER
17
1
⁄
2
-IN. (444mm) WIDE
CASINGS ONLY:
INSTALL FIELD-SUPPLIED
FILTER FILLER STRIP
UNDER FILTER.
1
″
24
1
/
2
″
3
″
21-IN. (533mm) WIDE
CASINGS ONLY:
SUPPORT RODS (3)
EXTEND 1/4" (6mm) ON
EACH SIDE OF FILTER AND
REST ON CASING FLANGE
(76mm)
(533mm)
(25.4mm)
A00290
Fig. 27 --
Bottom Filter Arrangement
BOTTOM
CLOSURE
PANEL
FRONT FILLER
PANEL
A93047
Fig. 28 -- Removing Bottom Closure Panel
Table 5 –
Maximum Capacity of Pipe*
NOMINAL
IRON PIPE
SIZE
IN. (MM)
INTERNAL
DIA.
IN. (MM)
LENGTH OF PIPE --- FT (M)
10
(3.0)
20
(6.0)
30
(9.1)
40
(12.1)
50
(15.2)
1/2 (12.7)
0.622
(158)
175
120
97
82
73
3/4 (19.0)
0.824
(20.9)
360
250
200
170
151
1 (25.4)
1.049
(26.6)
680
465
375
320
285
1-1/4
(31.8)
1.380
(35.0)
1400
950
770
660
580
1-1/2
(38.1)
1.610
(40.9)
2100
1460
1180
990
900
* Cubic ft of gas per hr for gas pressures of 0.5 psig (14---in. wc) or less and
a pressure drop of 0.5---in wc (based on a 0.60 specific gravity gas). Ref:
Table 9.2 NFGC.
FIRE OR EXPLOSION HAZARD
Failure to follow this warning could result in personal injury,
death, or property damage.
-Connect gas pipe to furnace using a backup wrench to avoid
damaging gas controls.
-Gas valve shutoff switch MUST be facing forward or
tilted upward.
-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.
-Use proper length of pipe to avoid stress on gas
control manifold.
-If a flexible connector is required or allowed by authority
having jurisdiction, black iron pipe shall be installed at furnace
gas valve and extend a minimum of 2 in. (51 mm) outside
furnace casing.
-Protect gas valve from water and debris. Gas valve inlet
and/or inlet piping 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.
!
WARNING
Install a sediment trap in riser leading to furnace. Trap can be
installed by connecting a tee to riser leading to furnace so
straight-through section of tee is vertical. Then connect a capped
nipple into lower end of tee. Capped nipple should extend below
level of gas controls. Place a ground joint union between gas
control manifold and manual gas shutoff valve. (See Fig. 29.)
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.