Burnham 4NP Ratings

High Pressure Steam Boilers

Model 4NP-68 Rating Data

for Biomass/Wood Firing

MODEL

MBH

HP

LBS/HR

LBS/HR

SQ FT

CU FT

WATER

STEAM

LBS

4NP4305-68

21193

633

21842

4499

4305

716.2

4465

3381

61996

GROSS RATING WATER CONTENT

BOILER STEAM RATE HTG SURF VOLUME WEIGHT

4NP625-68 3077 92 3171 653 625 148.5 941 764 16211

4NP925-68 4554 136 4693 967 925 186.6 1195 1006 19675
4NP1250-68 6153 184 6342 1306 1250 238.0 1486 1188 24562
4NP1538-68 7571 226 7803 1607 1538 315.7 1789 1450 27390
4NP1850-68 9107 272 9386 1934 1850 407.7 2118 1681 32595
4NP2153-68 10599 317 10923 2250 2153 471.9 2609 2056 39030
4NP2500-68 12307 368 12684 2613 2500 521.3 2820 2209 40190
4NP3075-68 15138 452 15601 3214 3075 500.4 3406 2586 46370
4NP3690-68 18165 543 18721 3857 3690 574.1 3842 2901 55000

NOTES:

1 BOILER MODEL SUFFIX "68" INDICATES 6.8 SQ.FT.F.S.H.S. / HP
2 FIRING RATE BASED ON BIOMASS/WOOD FUEL AT 6000 BTU/LB AND

78.5% OPERATING EFFICIENCY

3 FURNACE VOLUME IS MEASURED FROM THE BOTTOM OF THE BOILER MUDLEG.

FIRING FIRESIDE FURNACE DRY

GALLONS