Ratings
2
Series 4N Natural Draft Firebox Boiler
Ratings for Oil, Gas or Stoker Firing
4N Boiler Models 63 78 92 107 127 154 180 209 240 277 311 345 397
Gross Output MBH
BHP
Lbs.Stm./Hr.
245
7.3
253
299
8.9
308
348
10.4
359
403
12.0
415
522
15.6
538
626
18.7
645
724
21.6
746
870
26.0
897
996
29.8
1,027
1,142
34.1
1,177
1,278
38.2
1,317
1,414
42.2
1,457
21,60
65
2,226
Net Rating Steam MBH
Sq. Ft.
190
790
232
970
270
1,125
313
1,305
405
1,690
486
2,025
562
2,340
675
2,815
773
3,220
887
3,695
992
4,235
1,098
4,570
1,667
6,990
Net Rating Water MBH
213 260 303 351 454 545 630 757 867 994 1,112 1,230 1,878
Firing Rate - Gas MBH
Light Oil (140,000 BTU/Gal.)
Heavy Oil (150,000 BTU/Gal.)
306
2.2
—
374
2.7
—
435
3.1
—
504
3.6
—
653
4.7
—
783
5.6
—
905
6.5
—
1,088
7.8
—
1,245
8.9
—
1,428
10.2
—
1,598
11.4
—
1,768
12.6
—
2,700
19.3
18.0
Coal (Stoker) Lbs./Hr.
25 31 36 41 54 64 74 89 102 117 131 145 222
Heating Surface Sq. Ft.
Fireside
Waterside
45
47
55
57
64
67
74
77
96
100
115
120
133
139
153
160
183
193
210
221
235
247
260
274
397
429
Furnace Volume Cu. Ft. *
8.8 10.7 12.6 14.6 18.3 21.9 25.3 29.1 34.7 39.7 44.4 49.1 58.9
Heat Release MBH/Cu. Ft.
34.8 35.0 34.5 34.5 35.7 35.8 35.8 37.4 35.9 36.0 36.0 36.0 45.8
Water Content Gals.
Steam
Water
67
92
83
114
96
134
113
156
133
168
149
200
171
231
197
267
209
283
239
323
267
362
295
401
421
520
Approx. Dry Weight Lbs.
1,500 1,700 1,900 2,200 2,500 2,800 3,100 3,400 3,900 4,300 4,900 5,200 6,500
Approx. Weight Full Lbs.
Steam
Water
2,055
2,265
2,390
2,650
2,700
3,020
3,140
3,500
3,605
3,895
4,040
4,465
4,525
5,025
5,040
5,620
5,635
6,250
6,285
6,985
7,120
7,910
7,650
8,535
10,005
10,830
4N Boiler Models 463 563 662 827 993 1157 1323 1654 1985 2315 2645 3075
Gross Output MBH
BHP
Lbs.Stm./Hr.
2,519
75
2,596
3,063
92
3,156
3,601
108
3,712
4,499
134
4,636
5,402
161
5,567
6,294
188
6,484
7,197
215
7,417
8,998
269
9,273
10,798
323
11,129
12,594
376
12,979
14,389
430
14,829
16,738
500
17,250
Net Rating Steam MBH
Sq. Ft.
1,956
8,150
2,378
9,910
2,796
11,650
3,493
14,555
4,194
17,475
4,887
20,360
5,588
23,280
6,986
29,110
8,384
34,930
9,778
40,740
11,172
46,550
12,989
54,120
Net Rating Water MBH
2,190 2,663 3,131 3,912 4,697 5,473 6,258 7,824 9,390 10,951 12,512 14,554
Firing Rate - Gas MBH
Light Oil (140,000 BTU/Gal.)
Heavy Oil (150,000 BTU/Gal.)
3,149
22.5
21.0
3,829
27.3
25.5
4,501
32.1
30.0
5,624
40.2
37.5
6,753
48.2
45.0
7,868
56.2
52.5
8,996
64.3
60.0
11,248
80.3
75.0
13,498
96.4
90.0
15,743
112.5
104.9
17,986
128.5
120.0
20,923
149.5
139.5
Coal (Stoker) Lbs./Hr.
258 314 369 461 554 646 738 923 1,108 1,292 1,476 1,717
Heating Surface Sq. Ft.
Fireside
Waterside
463
500
563
608
662
715
827
893
993
1,072
1,157
1,250
1,323
1,429
1,654
1,786
1,985
2,143
2,315
2,500
2,645
2,857
3,075
3,321
Furnace Volume Cu. Ft. *
68.0 89.3 104.7 115.6 139.2 160.7 186.5 234.0 301.6 348.6 383.8 505.6
Heat Release MBH/Cu. Ft.
46.3 42.9 43.0 48.7 48.5 49.0 48.2 48.1 44.8 45.2 46.9 41.4
Water Content Gals.
Steam
Water
492
607
602
740
712
875
761
1,003
925
1,220
1,050
1,330
1,227
1,554
1,443
1,826
1,720
2,147
1,979
2,473
2,173
2,718
2,814
3,665
Approx. Dry Weight Lbs.
8,000 8,500 10,100 12,300 13,300 16,600 18,600 21,700 26,500 32,800 37,500 48,200
Approx. Weight Full Lbs.
Steam
Water
12,100
13,055
13,515
14,665
16,030
17,390
18,630
20,645
21,005
23,455
25,340
27,675
28,815
31,540
33,710
36,900
40,815
44,370
49,270
53,385
55,590
60,120
71,630
78,710
All models have 3 inch diameter tubes—except 3075 has 2-1/2 inch tubes
* = deos not include base volume