Page 30
GROUND
JOINT
UNION
AUTOMATIC
GAS VALVE
(with manual
shut-off valve)
FIELD
PROVIDED
AND INSTALLED
GROUND
JOINT
UNION
Left Side Piping
(Standard)
Right Side Piping
(Alternate)
AUTOMATIC
GAS VALVE
(with manual
shut-off valve)
DRIP LEG
DRIP LEG
MANUAL
MAIN SHUT-OFF
VALVE
(1/8 in. NPT
plugged tap shown)
MANUAL
MAIN SHUT-OFF
VALVE
(1/8 in. NPT
plugged tap
shown)
NOTE - BLACK IRON PIPE ONLY TO BE ROUTED INSIDE OF CABINET
FIGURE 42
TABLE 10
Gas Pipe Capacity - ft3/hr (m3/hr)
Nominal
Iron Pipe
Size Inches
(mm)
Internal
Diameter
inches
(mm)
Length of Pipe - feet (m)
10
(3.048)
20
(6.096)
30
(9,144)
40
(12,192)
50
(15.240)
60
(18.288)
70
(21.336)
80
(24.384)
90
(27.432)
100
(30,480)
1/2
(12.7)
.622
(17.799)
172
(4.87)
118
(3.34)
95
(2.69)
81
(2.29)
72
(2.03)
65
(1.84)
60
(1.69)
56
(1.58)
52
(1.47)
50
(1.42)
3/4
(19.05)
.824
(20.930)
360
(10.19)
247
(7.000)
199
(5.63)
170
(4.81)
151
(4.23)
137
(3.87)
126
(3.56)
117
(3.31)
110
(3.11)
104
(2.94)
1
(25.4)
1.049
(26.645)
678
(19.19)
466
(13.19)
374
(10.59)
320
(9.06)
284
(8.04)
257
(7.27)
237
(6.71)
220
(6.23)
207
(5.86)
195
(5.52)
1-1/4
(31.75)
1.380
(35.052)
1350
(38.22)
957
(27.09)
768
(22.25)
657
(18.60)
583
(16.50)
528
(14.95)
486
(13.76)
452
(12.79)
424
(12.00)
400
(11.33)
1-1/2
(38.1)
1.610
(40.894)
2090
(59.18)
1430
(40.49)
1150
(32.56)
985
(27.89)
873
(24.72)
791
(22.39)
728
(20.61)
677
(19.17)
635
(17.98)
600
(17.00)
2
(50.8)
2.067
(52.502)
4020
(113.83)
2760
(78.15)
2220
(62.86)
1900
(53.80)
1680
(47.57)
1520
(43.04)
1400
(39.64)
1300
(36.81)
1220
(34.55)
1160
(32.844)
2-1/2
(63.5)
2.469
(67.713)
6400
(181.22)
4400
(124.59)
3530
(99.95)
3020
(85.51)
2680
(75.88)
2480
(70.22)
2230
(63.14)
2080
(58.89)
1950
(55.22)
1840
(52.10)
3
(76.2)
3.068
(77.927)
11300
(319.98)
7780
(220.30)
6250
(176.98)
5350
(151.49)
4740
(134.22)
4290
(121.47)
3950
(111.85)
3670
(103.92)
3450
(97.69)
3260
(92.31)
NOTE - Capacity given in cubic feet (m3 ) of gas per hour and based on 0.60 specic gravity gas.
Removal of the Furnace from Common Vent
In the event that an existing furnace is removed from a
venting system commonly run with separate gas applianc-
es, the venting system is likely to be too large to properly
vent the remaining attached appliances.
Conduct the following test while each appliance is oper-
ating and the other appliances (which are not operating)
remain connected to the common venting system. If the
venting system has been installed improperly, you must
correct the system as indicated in the general venting re-
quirements section.