Steam Pipes - Heat Losses
The amount of condensate generated in a steam pipe depends on the heat loss from the pipe to the surroundings.
The heat loss is a function of the pipe size and insulation quality, the steam temperature (pressure) and the surrounding temperature.
Download and print Steam Pipe Heat Loss diagram
The table below and figure above can be used for estimating heat loss from bare uninsulated horizontal steam pipes - still air conditions - air temperature ranging 50 oF to 70 oF.
Difference between Steam Temperature and Surrounding Air Temperature (oF) | Heat Loss (Btu/h per ft) | |||||||||
---|---|---|---|---|---|---|---|---|---|---|
Dimension (inches) | ||||||||||
1/2 | 3/4 | 1 | 1 1/4 | 1 1/2 | 2 | 2 1/2 | 3 | 4 | 6 | |
100 | 56 | 68 | 82 | 107 | 113 | 138 | 163 | 194 | 243 | 337 |
120 | 71 | 85 | 104 | 127 | 142 | 175 | 206 | 246 | 308 | 427 |
140 | 86 | 104 | 127 | 155 | 173 | 212 | 251 | 300 | 375 | 521 |
160 | 103 | 125 | 152 | 186 | 213 | 256 | 301 | 360 | 451 | 626 |
180 | 121 | 146 | 176 | 217 | 243 | 297 | 351 | 417 | 522 | 725 |
200 | 139 | 171 | 206 | 251 | 282 | 346 | 408 | 488 | 622 | 850 |
225 | 166 | 199 | 243 | 297 | 334 | 410 | 483 | 578 | 726 | 1009 |
250 | 192 | 233 | 284 | 347 | 389 | 478 | 563 | 674 | 849 | 1180 |
275 | 220 | 266 | 326 | 398 | 447 | 550 | 649 | 778 | 978 | 1360 |
300 | 251 | 304 | 372 | 455 | 510 | 628 | 742 | 888 | 1140 | 1557 |
325 | 285 | 343 | 425 | 520 | 580 | 705 | 843 | 1010 | 1240 | 1730 |
350 | 322 | 388 | 480 | 590 | 660 | 790 | 945 | 1130 | 1358 | 1930 |
- 1 Btu/h per ft = 0.96 W/m