393. The head necessary to send water through a given length of pipe, of any diameter, is shown by the formula
C
D + C′ = H.
Where C = a constant.
C′ = constant for diameter of pipe.
D = diameter of pipe.
H = heads required.
The experimental values of C and C′ are as follows: Let V equal the velocity in feet per minute, and we have
| V. | C. |
|---|---|
| 60 | 8.62 |
| 70 | 11.40 |
| 80 | 14.58 |
| 90 | 17.95 |
| 100 | 21.56 |
| 120 | 29.70 |
| 140 | 38.90 |
| 150 | 44.00 |
| 180 | 62.13 |
Also, the values of C′ are
| Diameter of pipe. | C′. |
|---|---|
| 2 | .000 |
| 3 | .006 |
| 4 | .028 |
| 5 | .053 |
| 6 | .078 |
| 7 | .104 |
| 8 | .134 |