GAS PIPING
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.
FIRE OR EXPLOSION HAZARD
Failure to follow this warning coud 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.
Gas piping must be installed in accordance with national and local
codes. Refer to current edition of NFGC in the U.S., the NSCNG-
PIC in Canada.
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 licensed
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 approved by
the state of Massachusetts.
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. 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.
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. outside the furnace.
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.
An accessible manual equipment shutoff valve MUST be installed
external to furnace casing and within 6 ft of furnace. A 1/8-in. 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 connec-
tion is suitable to use as test gauge connection providing test
pressure DOES NOT exceed maximum 0.5 psig (14-in. wc) stated
on gas control valve. (See Fig. 52.)
Some installations require gas entry on right side of furnace (as
viewed in upflow.) (See Fig. 21a.)
Install a sediment trap in riser leading to furnace as shown in Fig
21b. 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. NPT plugged tapping,
accessible for test gauge connection, MUST be installed immedi-
ately upstream of gas supply connection to furnace and down-
stream of manual equipment shutoff valve.
Table 5—Air Delivery - CFM (With Filter)* (Continued)
FURNACE
SIZE
RETURN-AIR
INLET
SPEED
EXTERNAL STATIC PRESSURE (IN. WC)
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
048135
Bottom
or
Side(s)
High
Med-High
Med-Low
Low
2090
1790
1545
1325
2010
1755
1525
1320
1930
1705
1500
1295
1835
1640
1450
1265
1710
1550
1380
1210
1590
1465
1315
1150
1470
1360
1215
995
1335
1210
1005
865
1025
945
855
745
835
785
670
540
066135
Bottom
Only
High
Med-High
Med-Low
Low
2485
2195
1880
1640
2400
2150
1850
1635
2310
2090
1820
1615
2215
2000
1780
1585
2110
1920
1715
1530
2000
1825
1635
1465
1880
1720
1540
1370
1725
1565
1415
1255
1535
1405
1290
1150
1355
1255
1160
1040
Bottom, Sides or
1 Side & Bottom
High
Med-High
--
2180
--
2145
2385
2060
2305
2010
2195
1945
2085
1865
1960
1765
1825
1660
1670
1515
1465
1325
1 Side Only
High
Med-High
--
2135
--
2085
2245
2035
2155
1975
2055
1895
1940
1795
1825
1685
1695
1565
1555
1445
1385
1265
060155
Bottom
Only
High
Med-High
Med-Low
Low
2465
2115
1800
1570
2430
2105
1790
1565
2375
2075
1770
1550
2305
2030
1735
1525
2230
1980
1695
1495
2110
1910
1640
1445
2000
1830
1570
1370
1865
1725
1465
1270
1725
1590
1345
1175
1545
1425
1225
1070
Both Sides Or
1 Side & Bottom
High
Med-High
--
2155
--
2135
2375
2095
2285
2040
2200
1975
2105
1895
1995
1790
1870
1685
1730
1550
1570
1400
1 Side Only
High
Med-High
--
2140
--
2095
2260
2040
2180
1975
2085
1890
1975
1810
1865
1705
1740
1595
1605
1480
1455
1325
*A filter is required for each return-air inlet. Airflow performance included 1-in. washable filter media such as contained in factory-authorized accessory filter rack. To
determine airflow performance without this filter, assume an additional 0.1 in. wc available external static pressure.
--
Indicates unstable operating conditions.
17
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