MUA-SVX004B-EN
23
•
250 cfh is supplied from B to D, requiring 1 inch pipe.
•
100 cfh is supplied from D to E, requiring 3/4 inch pipe.
•
150 cfh is supplied from D to F, requiring 1 inch pipe.
N
No
otte
ess::
•
For SI calculations, refer to metric conversion chart in general safety section of this
manual.
•
If more than one gas duct furnace is to be served by the same piping arrangement, the
total cu. ft./hr. input and length of pipe must be considered.
•
If the gas duct furnace is to be fired with LP gas, consult local LP gas dealer for pipe
size information. Heater installation for use with propane (bottled) gas must be made
by a qualified LP gas dealer or installer. He will insure proper joint compounds are
used for making pipe connections; that air is purged from lines; that a thorough test is
made for leaks before operating heater; and that it is properly connected to propane
gas supply system.
•
Before any connection is made to an existing line supplying other gas appliances, contact the
local gas company to make certain that the existing line is of adequate size to handle the
combined load.
•
Check all connections with a soap solution before leaving job.
Figure 13.
Example of Piping Layout for Determining Size
GAS METER
A
20 ft.
6.56 m.
20 ft.
6.56 m.
5 ft.
1.64 m.
5 ft.
1.64 m.
10 ft.
3.48 m.
B
C
D
F
E
10 ft.
3.28 m.
HEATER(S)
200 CFH
HEATER(S)
150 CFH
HEATER(S)
100 CFH
Table 3. Gas Pipe Size
Nominal
Iron
Pipe Size
Dia.
Internal
Length of Pipe, ft. (Meters)
in.
30
in.
50
20
10
40
60
70
80
90
Maximum Capacity of Pipe in Cubic Feet of Gas per Hour for Gas Pressures of 0.5 psig (3.5 kPa) or Less,
and a Pressure Drop of 0.5 Inch Water Column (124.4 Pa)
(Based on a 0.60 Specifi c Gravity Gas)
100
125
150
200
175
(mm)
(3.0)
(6.1)
(9.1)
(12.2)
(15.2) (18.3)
(21.3)
(24.4)
(27.4)
(30.5)
(38.1)
(45.7)
(53.3)
(61.0)
0.622
175
2
/
1
97
120
82
73
35
44
40
53
50
57
61
66
37
(16)
(4.96)
(3.40)
(2.75)
(2.32)
(2.07) (1.87)
(1.73)
(1.61)
(1.50)
(1.42)
(1.25)
(1.13)
(1.05)
(0.99)
0.824
360
4
/
3
170
200
151
250
138
125
118
110
103
93
84
72
77
(21)
(10.2)
(7.08)
(5.66)
(4.81)
(4.28) (3.91)
(3.54)
(3.34)
(3.11)
(2.92)
(2.63)
(2.38)
(2.18)
(2.04)
1
680
1.049
375
320
285
465
135
205
195
175
145
160
260
240
220
(27)
(19.3)
(13.2)
(10.6)
(9.06)
(8.07) (7.36)
(6.80)
(6.23)
(5.80)
(5.52)
(4.96)
(4.53)
(4.11)
(3.82)
1400
770
660
580
1 1/4
1.380
950
280
530
490
460
430
400
360
325
300
(35)
(39.6)
(26.9)
(21.8)
(18.7)
(16.4) (15.0)
(13.9)
(13.0)
(12.2)
(11.3)
(10.2)
(9.20)
(8.50)
(7.93)
2100
1460
1180
1 1/2
1.610
900
990
430
810
750
690
650
620
550
500
460
(41)
(59.5)
(41.3)
(33.4)
(28.0)
(25.5) (22.9)
(21.2)
(19.5)
(18.4)
(17.6)
(15.6)
(14.2)
(13.0)
(12.2)
2
2.067
3950
2200
1900
1680
2750
1020
1150
1520
1400
1300
1220
950
800
850
(53)
(112)
(77.9)
(62.3)
(53.8)
(47.6) (43.0)
(39.6)
(36.8)
(34.5)
(32.6)
(28.9)
(26.9)
(24.1)
(22.7)
6300
3000
3520
2650
4350
2 1/2
2.469
1280
1650
1850
1950
2050
2250
1500
2400
1370
(63)
(178)
(123)
(99.7)
(85.0)
(75.0) (68.0)
(63.7)
(58.0)
(55.2)
(52.4)
(46.7)
(42.5)
(38.8)
(36.2)
3.068
3
11000
6250
5300
4750
7700
2280
2650
4300
3900
2450
3700
2950
3250
3450
(78)
(311)
(218)
(177)
(150)
(135)
(122)
(110)
(105)
(97.7)
(92.0)
(83.5)
(75.0)
(69.4)
(64.6)
4.026
4
23000
15800
12800
10900
9700
4600
8800
8100
7200
7500
6700
6000
5500
5000
(102)
(651)
(447)
(362)
(309)
(275)
(249)
(229)
(212)
(204)
(190)
(170)
(156)
(142)
(130)
