Bradford White RTG 199 MEN Installation And Operation Instructions Manual page 24

Installation instructions
4.9.1 Gas Line Sizing Tables for NATURAL GAS
For your convenience see below for an excerpt from gas line sizing tables for a single NG appliance. For details see the current NFPA 54.
Specified pipe lengths are for one RTG 199ME, which has a maximum input rating of 199,000 BTUs. The gas supply system must be sized for the
combined total maximum BTU/hr load requirements of all gas appliances running simultaneously.
The tables below show the maximum capacity of the gas supply pipe in cubic feet per hour. Please contact your local gas supplier for the energy content
of the gas to determine the BTU/hr capacity. Use 1,000 BTU/cubic foot for rough estimations.
Maximum pipe capacity in cubic feet of Natural Gas per hour for gas pressures of 14" W.C. (0.5 psig) or less and a pressure drop of 0.3" W.C.
(0.75mbar) based on 0.60 specific gravity gas).
Nominal Internal
Iron Pipe Diameter
Size, inches inches 10
3/4 0.824
1 1.049
1-1/4 1.380
1-1/2 1.610
Table 25
Maximum pipe capacity in cubic feet of Natural Gas per hour for gas
pressures of <2.0 psig (55" WC or 138 mbar) and a pressure drop of
3.0" W.C. (7.5 mbar) based on 0.60 specific gravity gas).
Nominal Iron Internal
Pipe Size, Diameter
inches inches
1/2 0.622
3/4 0.824
1 1.049
Table 26
Maximum pipe capacity in cubic feet of Natural Gas per hour for gas
pressures of 14" W.C. (0.5 psig or 25 mbar) or less and a pressure drop
of 0.5" W.C. (1.25mbar) based on 0.60 specific gravity gas).
Tube
size,
inches EHD*
1 30
1 31
1 - 1/4 37
1 - 1/4 38
Table 27
* EHD = Equivalent Hydraulic Diameter. The greater the value of EHD, the
greater the gas capacity of the tubing.
28
Length of Black iron Pipe (Schedule 40 Metallic Pipe), Feet
20 30
273 188 151
514 353 284
1060 726 583
1580 1090 873
Length of Black Iron Pipe (Schedule 40 Metallic Pipe), Feet
10 20 30
454 312 250
949 652 524
1787 1228 986
Length of Corrugated Stainless Steel Tubing (CSST), Feet
10 20 30
330 231 188
383 269 218
639 456 374
746 526 442
40 50 60
129 114 104
243 215 195
499 442 400
747 662 600
Minimum Gas Pressure 8.0" WC (20 mbar)
40 50 60
214 190 172
448 397 360
844 748 678
40 50 60
162 144 131
188 168 153
325 292 267
386 347 318
70 80 90
95 89 83
179 167 157
368 343 322
552 514 482
70 80 90
158 147 138
331 308 289
624 580 544
70 80 90
121 113 107
141 132 125
248 232 219
295 277 262
RTG 199 ME – 6 720 811 615 (2015/04)
100
79
148
304
455
100
131
273
514
100
101
118
208
249