Form I-XE/CRGB/RPB, Mfg No. 131782 Rev 4, Page 15
Sizing Gas
Supply Lines
Pipe joint compounds (pipe dope) shall be resistant to the ac-
tion of liquefied petroleum gas or any other chemical con-
stituents of the gas being supplied.
Install a ground joint union and manual shutoff valve upstream of
the unit control system, as shown in
FIGURES 16 and 17
. The
1/8" plugged tapping in the shutoff valve provides connection for
supply line pressure test gauge. The National Fuel Gas Code re-
FIGURE 16 - Gas Connection Location, Indoor Model
Thermostat Wire
Manual Shutoff Valve
with 1/8 NPT plugged
tapping must be installed
above unit casing.
Line Voltage
(Supply)
Junction
Box
To Gas Controls
and Burner
Ground
Joint
Union
Top View
Side View
4 (102mm)
2-3/32 (53mm)
5-5/8 (143mm)
6-7/8 (175mm)
7/8 (22mm) dia. 1-7/8 x 1-3/8 (48x35mm)
Minimum 1 (25mm) clearance between
heater access panel and elbow or fitting
Install a 1/8 NPT plug with tap
for test gauge immediately upstream
of the gas supply connection
Manual shutoff valve
Installer supplies
manual shutoff,
ground unions
and shaded piping
Gas Supply
Entrance
5
-3/4
(146mm)
Condensate
Weep Holes
FIGURE 17 - Gas Connection Location, Outdoor Models
Install the gas supply piping
so that when the union is
disconnected, the supply pipe
will not interfere with the
removal of the burner rack.
(The burner rack slides out
of the control side of the
furnace.)
Sizes
Natural Propane
Sizes
Natural Propane
75-250
1/2"
1/2"
300-400
3/4"
1/2"
Gas Connection to S ingle-S tage Valve
(Not Gas Supply Line Size)
Applies to all M odels in this M anual
quires the installation of a trap with a minimum 3" (76mm) drip leg. Local
codes may require a minimum drip leg longer than 3" (76mm), typically 6"
(152mm).
After all connections are made, disconnect the pilot supply at the control
valve and bleed the system of air. Reconnect the pilot line and leak-test all
connections by brushing on a soap solution.
WARNING: All components of a gas supply system
must be leak tested prior to placing equipment in
service. NEVER TEST FOR LEAKS WITH AN
OPEN FLAME. Failure to comply could result in
personal injury, property damage or death.
Capacity of Piping
Cubic Feet per Hour based on 0.3" w.c. Pressure Drop
Specific Gravity for Natural Gas -- 0.6 (Natural Gas -- 1000 BTU/Cubic Ft)
Specific Gravity for Propane Gas -- 1.6 (Propane Gas -- 2550 BTU/Cubic Ft)
Length
Diameter of Pipe
of 1/2"
3/4"
1"
1-1/4"
1-1/2"
2"
Pipe
Natural Propane Natural Propane Natural Propane Natural Propane Natural Propane Natural Propane
20'
92
56
190
116
350
214
730
445
1100
671
2100
1281
30'
73
45
152
93
285
174
590
360
890
543
1650
1007
40'
63
38
130
79
245
149
500
305
760
464
1450
885
50'
56
34
115
70
215
131
440
268
670
409
1270
775
60'
50
31
105
64
195
119
400
244
610
372
1105
674
70'
46
28
96
59
180
110
370
226
560
342
1050
641
80'
43
26
90
55
170
104
350
214
530
323
990
604
90'
40
24
84
51
160
98
320
195
490
299
930
567
100'
38
23
79
48
150
92
305
186
460
281
870
531
125'
34
21
72
44
130
79
275
168
410
250
780
476
150'
31
19
64
39
120
73
250
153
380
232
710
433
175'
28
17
59
36
110
67
225
137
350
214
650
397
200'
26
16
55
34
100
61
210
128
320
195
610
372
Note: When sizing supply lines, consider possibilities of future expansion and increased requirements.
Refer to National Fuel Gas Code for additional information on line sizing.
Manifold or Orifice Pressure Settings
Measuring gas valve outlet (manifold) pressure cannot be done until
the heater is in operation. It is included in the "Check-Test-Start"
section, Paragraph 30. The following instructions apply.
WARNING: Manifold gas pressure must never
exceed 3.5" w.c. for natural gas and 10" w.c. for
propane gas.
