Navien NPE-180A Installation Manual page 18

3.3.1 Gas Pipe Sizing Tables (Referenced from 2012 National Fuel Gas Code)
These tables are for reference only. Please consult the gas pipe manufacturer for actual pipe capacities.
Maximum Natural Gas Delivery Capacity
3
in Cubic Feet (ft ) per Hour (0.60 Specific Gravity; 0.5 in WC Pressure Drop). Contact your gas supplier for BTU/ft
simplified calculations. This table is recommended for supply pressures less than 6 in WC.
Length (including fittings)
Pipe Size
10 ft
(3 m)
3 / in 360
4
1 in 678
1
1 / in 1,390
4
1 1 / in 2,090
2
2 in 4,020
1
2 / in 6,400
2
3 in 11,300
4 in 23,100
in Cubic Feet (ft 3
) per Hour (0.60 Specific Gravity; 3.0 in WC Pressure Drop). Contact your gas supplier for BTU/ft
simplified calculations. This table is recommended for supply pressures of 6 in WC or greater.
Length (including fittings)
Pipe Size
10 ft
(3 m)
1
/ in 454
2
3
/ in 949
4
1 in 1,787
1
1 / in 3,669
4
1
1 / in 5,497
2
2 in 10,588
2 1 / in 16,875
2
3 in 29,832
4 in 43,678
18 Installing the Water Heater
20 ft 30 ft 40 ft
(6 m) (9 m) (12 m)
247 199 170
466 374 320
957 768 657
1,430 1,150 985
2,760 2,220 1,900
4,400 3,530 3,020
7,780 6,250 5,350
15,900 12,700 10,900
20 ft 30 ft 40 ft
(6 m) (9 m) (12 m)
312 250 214
652 524 448
1,228 986 844
2,522 2,025 1,733
3,778 3,034 2,597
7,277 5,844 5,001
11,598 9,314 7,971
20,503 16,465 14,092
30,020 24,107 20,632
50 ft 60 ft 70 ft
(15 m) (18 m) (21 m)
151 137 126
284 257 237
583 528 486
873 791 728
1,680 1,520 1,400
2,680 2,430 2,230
4,740 4,290 3,950
9,660 8,760 8,050
50 ft 60 ft 70 ft
(15 m) (18 m) (21 m)
190 172 158
397 360 331
748 678 624
1,536 1,392 1,280
2,302 2,085 1,919
4,433 4,016 3,695
7,065 6,401 5,889
12,489 11,316 10,411
18,286 16,569 15,243
3
ratings. Use 1,000 BTU/ft
80 ft 90 ft 100 ft
(24 m) (27 m) (30 m)
117 110 104
220 207 195
452 424 400
677 635 600
1,300 1,220 1,160
2,080 1,950 1,840
3,670 3,450 3,260
7,490 7,030 6,640
3
ratings. Use 1,000 BTU/ft
80 ft 90 ft 100 ft
(24 m) (27 m) (30 m)
147 138 131
308 289 273
580 544 514
1,191 1,118 1,056
1,785 1,675 1,582
3,437 3,225 3,046
5,479 5,140 4,856
9,685 9,087 8,584
14,181 13,305 12,568
3
for
125 ft
(38 m)
92
173
355
532
1,020
1,630
2,890
5,890
3
for
125 ft
(38 m)
116
242
456
936
1,402
2,700
4,303
7,608
11,139