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21
Gas Headers (Propane)
1. Determine Btuh input for each bank of modules.
2. Determine the length of the header, which is typically
dependent on the length of the bank of modules which it
serves.Use the “Length” column in Figure A2. In most
cases, the header is straight pipe only.
3. In Figure B2, find appropriate pipe length in upper por-
tion of table under "Length of Pipe, Feet" heading.
4. Move down the column; match the Btuh input from
Step 1. Higher capacity selection is acceptable.
5. Move across to the left-hand column "Nominal Iron
Pipe Size, Inches" and read required pipe size.
Gas Main (Propane)
1. Determine Btuh input for the total heating plant.
2. Determine total equivalent length of gas main. Re-
member, if exact number/type of fittings are not known,
for initial determination only, add 20% for fittings to the
straight length of piping to get a total equivalent length.
3. In Figure B2, find appropriate pipe length in upper por-
tion of table under "Length of Pipe, Feet" heading.
4. Move down the column; match the Btuh input from
Step 1. Higher capacity selection is acceptable.
5. Move across to the left-hand column "Nominal Iron
Pipe Size, Inches" and read required pipe size.
6. Once a diameter has been selected, verify the total
equivalent length.
Maximum Capacity of Pipe in Thousands of Btu per Hour of Undiluted Liquified
Petroleum Gases (at 11 Inches Water Column Inlet Pressure)
(Based on a Pressure Drop of 0.5 Inch Water Column)
Nominal
Iron Pipe
Size,
Inches
Length of Pipe, Feet
10
275
567
1071
2205
3307
6221
20
189
393
732
1496
2299
4331
30
152
315
590
1212
1858
3465
40
129
267
504
1039
1559
2992
50
114
237
448
937
1417
2646
60
103
217
409
834
1275
2394
70
96
196
378
771
1180
2205
80
89
185
346
724
1086
2047
90
83
173
322
677
1023
1921
100
78
162
307
630
967
1811
125
69
146
275
567
866
1606
150
63
132
252
511
787
1498
1/2"
3/4"
1"
1-1/4"
1-1/2"
2"
TABLE B2