The value .0027 is apparently the most nearly correct, and substituting in formula ( [43] ) gives,
| p | = | 0.000131 | ( | 1 | + | | ) | | ( 44 ) |
|
| w | = | 87 | ( | | p D d15 | | –––––––––––––––––––––––––– | |
| ) ½ | ( 45 ) |
|
| Where | w | = | the weight of steam passing in pounds per minute, |
| p | = | the difference in pressure between the two ends of the pipe in pounds per square inch, |
| D | = | density of steam or weight per cubic foot, [80] |
| d1 | = | internal diameter of pipe in inches, |
| L | = | length of pipe in feet. |
[TABLE 66]
FLOW OF STEAM THROUGH PIPES Initial
Gauge
Pressure
Pounds
per
Square
Inch | Diameter [81] of Pipe in Inches, Length of Pipe = 240 Diameters |
|---|
| ¾ | 1 | 1½ | 2 | 2½ | 3 | 4 | 5 | 6 | 8 | 10 | 12 | 15 | 18 |
|---|
| Weight of Steam per Minute, in Pounds, With One Pound Loss of Pressure |
|---|
| 1 | 1.16 | 2.07 | 5.7 | 10.27 | 15.45 | 25.38 | 46.85 | 77.3 | 115.9 | 211.4 | 341.1 | 502.4 | 804 | 1177 | | 10 | 1.44 | 2.57 | 7.1 | 12.72 | 19.15 | 31.45 | 58.05 | 95.8 | 143.6 | 262.0 | 422.7 | 622.5 | 996 | 1458 | | 20 | 1.70 | 3.02 | 8.3 | 14.94 | 22.49 | 36.94 | 68.20 | 112.6 | 168.7 | 307.8 | 496.5 | 731.3 | 1170 | 1713 | | 30 | 1.91 | 3.40 | 9.4 | 16.84 | 25.35 | 41.63 | 76.84 | 126.9 | 190.1 | 346.8 | 559.5 | 824.1 | 1318 | 1930 | | 40 | 2.10 | 3.74 | 10.3 | 18.51 | 27.87 | 45.77 | 84.49 | 139.5 | 209.0 | 381.3 | 615.3 | 906.0 | 1450 | 2122 | | 50 | 2.27 | 4.04 | 11.2 | 20.01 | 30.13 | 49.48 | 91.34 | 150.8 | 226.0 | 412.2 | 665.0 | 979.5 | 1567 | 2294 | | 60 | 2.43 | 4.32 | 11.9 | 21.38 | 32.19 | 52.87 | 97.60 | 161.1 | 241.5 | 440.5 | 710.6 | 1046.7 | 1675 | 2451 | | 70 | 2.57 | 4.58 | 12.6 | 22.65 | 34.10 | 56.00 | 103.37 | 170.7 | 255.8 | 466.5 | 752.7 | 1108.5 | 1774 | 2596 | | 80 | 2.71 | 4.82 | 13.3 | 23.82 | 35.87 | 58.91 | 108.74 | 179.5 | 269.0 | 490.7 | 791.7 | 1166.1 | 1866 | 2731 | | 90 | 2.83 | 5.04 | 13.9 | 24.92 | 37.52 | 61.62 | 113.74 | 187.8 | 281.4 | 513.3 | 828.1 | 1219.8 | 1951 | 2856 | | 100 | 2.95 | 5.25 | 14.5 | 25.96 | 39.07 | 64.18 | 118.47 | 195.6 | 293.1 | 534.6 | 862.6 | 1270.1 | 2032 | 2975 | | 120 | 3.16 | 5.63 | 15.5 | 27.85 | 41.93 | 68.87 | 127.12 | 209.9 | 314.5 | 573.7 | 925.6 | 1363.3 | 2181 | 3193 | | 150 | 3.45 | 6.14 | 17.0 | 30.37 | 45.72 | 75.09 | 138.61 | 228.8 | 343.0 | 625.5 | 1009.2 | 1486.5 | 2378 | 3481 | |
This formula is the most generally accepted for the flow of steam in pipes. [Table 66] is calculated from this formula and gives the amount of steam passing per [Pg 319] minute that will flow through straight smooth pipes having a length of 240 diameters from various initial pressures with one pound difference between the initial and final pressures.
To apply [this table] for other lengths of pipe and pressure losses other than those assumed, let L = the length and d the diameter of the pipe, both in inches; l , the loss in pounds; Q, the weight under the conditions assumed in [the table] , and Q 1 , the weight for the changed conditions.
For any length of pipe, if the weight of steam passing is the same as given in [the table] , the loss will be,