Page 245 - Facility Piping Systems Handbook for Industrial, Commercial, and Healthcare Facilities

HEAT TRANSFER, INSULATION, AND FREEZE PROTECTION

HEAT TRANSFER, INSULATION, AND FREEZE PROTECTION 5.29

T = ambient temperature at a distance from pipe that would not be affected by the heat of
2
the pipe (This would be either the ground temperature for buried pipe or the design
temperature of the air.)
A = area, in square feet, normal to the direction of heat flow of a 1-ft long section of pipe
(Where there is insulation, the cylinder of insulation should be used to calculate the
arithmetic mean of the area between the pipe wall and the outside of the insulation.
Refer to Table 5.6.)
X = distance, in inches, from the outside of the pipe wall where T is measured to where
1
T is taken
2
TABLE 5.10 Heat Loss from Typical Steel Tank on Grade

Tank capacities—in thousands of gallons
°F °C 100 150 200 300 400 500 750 1,000

35 2 85 114 135 175 206 238 312 380
30 –1 121 162 193 248 294 340 445 543
25 –4 161 216 257 330 393 453 594 722
20 –7 202 271 323 414 493 568 745 907
15 –10 245 329 391 502 537 689 904 1,099
10 –13 290 389 463 595 707 816 1,071 1,302
5 –15 337 452 539 691 822 949 1,244 1,514
0 –18 388 521 620 796 947 1,093 1,434 1,744
–5 –20 441 592 705 905 1,076 1,241 1,628 1,981
–10 –23 498 669 797 1,023 1,216 1,403 1,841 2,239
–15 –26 557 748 891 1,143 1,360 1,569 2,058 2,503
–20 –29 619 830 989 1,270 1,510 1,742 2,286 2,781
–25 –33 685 920 1,096 1,406 1,673 1,930 2,532 3,080
–30 –34 752 1,010 1,203 1,545 1,837 2,119 2,781 3,383
–35 –37 825 1,108 1,320 1,694 2,015 2,325 3,050 3,710
–40 –40 898 1,206 1,437 1,844 2,193 2,531 3,320 4,039
–50 –45 1,059 1,422 1,694 2,175 2,586 2,984 3,915 4,762
–60 –51 1,229 1,651 1,966 2,524 3,002 3,463 4,544 5,528

TABLE 5.11 Heat Loss in Riser of Elevated Storage Tanks
Btuloss per hour through 4-ft-diameter (3.3-m) riser per foot-length
Atmospheric
temperature, °F °C Btu/h
35 2 69
30 –1 192
25 –4 340
20 –7 506
15 –10 692
10 –13 893
5 –15 1,092
0 –18 1,309
–5 –20 1,536
–10 –23 1,771
–15 –26 2,020
–20 –29 2,291
–25 –33 2,568

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