a minute.
The actual horsepower of this tube and nozzle, then, can be figured by
applying formula (A), Chapter III, allowing 80 per cent for the
efficiency of the wheel. Thus:

Actual horsepower =

207 x 230.1 x 62.5
------------------ = 90.21 x .80 = 72.168 Hp.
33,000

To calculate what the horsepower of this tube 12 inches in diameter
and 900 feet long, would be without a nozzle, under a head of 240
feet, introduces a new element of friction losses, which is too
complicated to figure here. Such a condition would not be met with in
actual practice, in any event. The largest nozzles used, even in the
jumbo plants of the Far West, rarely exceed 10 inches in diameter; and
the pipe conveying water to such a nozzle is upwards of eight feet in
diameter.

PIPE FRICTION TABLES

INDICATING THE CALCULATED LOSS OF HEAD DUE TO FRICTION IN RIVETED
STEEL PIPE WITH VARIOUS WATER QUANTITIES AND VELOCITIES

[Courtesy of the Pelton Water Wheel Company]

Heavy-faced figures = Loss of head in feet for each one thousand
feet of pipe. Light-faced figures = Water quantity in cubic feet per
minute.

--------+-------------------------------------------------------------------------------------------+
Pipe | Velocity in Feet per Second |
Diameter+------+------+------+------+------+------+------+------+------+------+------+------+-------+
| 2.0 | 2.2 | 2.4 | 2.6 | 2.8 | 3.0 | 3.2 | 3.4 | 3.6 | 3.8 | 4.0 | 4.2 | 4.4 |
--------+------+------+------+------+------+------+------+------+------+------+------+------+-------+
|=17.1=|=20.0=|=25.6=|=28.3=|=32.0=|=37.3=|=40.9=|=45.8=|=50.4=|=56.0=|=62.3=|=68.1=|=74.9= |
3" | 5.9 | 6.5 | 7.1 | 7.7 | 8.3 | 8.9 | 9.4 | 10.0 | 10.6 | 11.2 | 11.8 | 12.4 | 13.0 |
|=11.0=|=13.0=|=15.0=|=17.3=|=20.2=|=23.2=|=26.2=|=29.6=|=33.0=|=36.5=|=41.0=|=45.4=|=49.2= |
4" | 10.5 | 11.5 | 12.6 | 13.6 | 14.7 | 15.7 | 16.8 | 17.8 | 18.8 | 19.9 | 21.0 | 22.0 | 23.0 |
| =7.7=| =9.4=|=11.0=|=12.9=|=14.9=|=16.9=|=19.5=|=21.6=|=24.0=|=27.0=|=29.8=|=32.9=|=36.0= |
5" | 16.4 | 18.0 | 19.6 | 21.2 | 22.9 | 24.5 | 26.1 | 27.8 | 29.5 | 31.0 | 32.7 | 34.3 | 36.0 |
| =6.0=| =7.2=| =8.6=| =9.9=|=11.7=|=13.0=|=14.6=|=16.6=|=19.0=|=21.5=|=23.4=|=25.5=|=27.8= |
6" | 23.5 | 25.9 | 28.2 | 30.6 | 32.9 | 35.3 | 37.7 | 40.0 | 42.4 | 44.7 | 47