d. The size of the pipe at the
head of this column is that which will carry the required amount of
steam with the assumed pressure drop.

The table may be used conversely to determine the pressure drop through
a pipe of a given diameter delivering a specified amount of steam by
passing from the known figure in the left to the column on the right
headed by the pressure which is the mean of the initial and final
pressures corresponding to the drop found and the actual initial
pressure present.

For a given flow of steam and diameter of pipe, the drop in pressure is
proportional to the length and if discharge quantities for other lengths
of pipe than 1000 feet are required, they may be found by proportion.

TABLE 68

FLOW OF STEAM INTO THE ATMOSPHERE
__________________________________________________________________
| | | | | |
| Absolute | Velocity | Actual | Discharge | Horse Power |
| Initial | of Outflow | Velocity | per Square | per Square |
| Pressure | at Constant | of Outflow | Inch of | Inch of |
| per Square | Density | Expanded | Orifice | Orifice if |
| Inch | Feet per | Feet per | per Minute | Horse Power |
| Pounds | Second | Second | Pounds | = 30 Pounds |
| | | | | per Hour |
|____________|_____________|____________|____________|_____________|
| | | | | |
| 25.37 | 863 | 1401 | 22.81 | 45.6 |
| 30. | 867 | 1408 | 26.84 | 53.7 |
| 40. | 874 | 1419 | 35.18 | 70.4 |
| 50. | 880 | 1429 | 44.06 | 88.1 |
| 60. | 885 | 1437 | 52.59 | 105.2 |
| 70. | 889 | 1444 | 61.07 | 122.1 |
| 75. | 891 | 1447 | 65.30 | 130.6 |
| 90. | 895 | 1454 | 77.94 | 155.9 |
| 100. | 898 | 1459 | 86.34 | 172.7 |
| 115. | 902 | 1466 | 98.76 | 197.5 |
| 135. | 906 | 1472 | 115.61 | 231.2 |
| 155. | 910 | 1478 | 132.21 | 264.4 |
| 165. | 912 | 1481 | 140.46 | 280.9