Form: 2435
Revision: 9
Free Flex Installation and Operation Manual
Date: 9-1-2017
Bryan Steam LLC, 783 N Chili Ave, Peru IN 46970
Web:
www.
bryanboilers
.com
Phone:
765-473-6651
Fax:
765-473-3074
Email:
sales@bryansteam.com
48
Appendix A
Sizing Gas Piping
Design the gas piping system to provide an adequate gas supply to the boiler. Refer to Table 6 for
minimum and maximum gas supply pressures and boiler capacities. Also consider existing and
expected future gas utilizing equipment (i.e., water heater, cooling equipment). Refer to Table 18 for
maximum capacity of schedule 40 pipe. Table 19 lists equivalent pipe length for standard fittings.
Given the specific gravity of gas at the boiler’s location, a correction factor can be found on Table
20 and multiplied by the “Capacity in Cubic Feet of Gas Per Hour” on Table 18. For gas piping
material other than schedule 40 pipes, refer to the National Fuel Gas Code, NFPA 54/ANZI
Z223.1 and/or CAN/CGA B149 Installation codes. Use methods and materials in accordance with
Local Codes and requirements of gas supplier. In the absence of such requirement follow National
Fuel Gas Codes, NFPA /ANSI Z 223.1 and/or CAN/CGA B149 Installation Codes.
Table 18: Maximum Gas Capacity Of Schedule 40 Pipe
Pipe
Length in
Equivalent
Feet
Pipe Size (nps)
¾
1
1-1/4
1-1/2
2
2-1/2
3
4
10
273
514
1060
1580
3050
4860
8580
17500
20
188
353
726
1090
2090
3340
5900
12000
30
151
284
583
873
1680
2680
4740
9660
40
129
243
499
747
1440
2290
4050
8270
50
114
215
442
662
1280
2030
3590
7330
60
104
195
400
600
1160
1840
3260
6640
70
95
179
368
552
1060
1690
3000
6110
80
89
167
343
514
989
1580
2790
5680
90
83
157
322
482
928
1480
2610
5330
100
79
148
304
455
877
1400
2470
5040
125
70
131
269
403
777
1240
2190
4460
150
63
119
244
366
704
1120
1980
4050
175
58
109
224
336
648
1030
1820
3720
200
54
102
209
313
602
960
1700
3460
Based on gas pressures less than 2 psig and a pressure drop of 3.0 iwc and 0.6 specific gravity.