APPENDIX. 
63 
B. TABLES FOR DETERMINING THE SIZE OF PUMP REQUIRED FOR 
DELIVERING WATER. 1 
Loss in Friction Head. 
Friction head in 2-inch pipe — 
1 mile. 
2 miles. 
3 miles. 
! Feet. 
Feet. 
Feet. 
51 
102 
153 
110 
220 
330 
194 
388 
582 
295 
592 
888 
468 
936 
1,404 
4 miles. 
20 gallons. 
30 gallons. 
40 gallons. 
50 gallons . 
60 gallons . 
Feet. 
204 
440 
776 
1,184 
1,872 
* From an article by Clyde E. Learned, Highway Engineer, Bureau of Public Roads, published in Public 
Roads, June, 1919. 
To the loss in head in the above table it will be necessary to add the 
vertical height that the water is to be pumped and to make allowance for 
angles and valves. 
The theoretical horsepower required to furnish water under different heads 
is given in the following table : 
Theoretical Horsepower Required. 
Total head. 1 
Water required per minute. 
100 
feet. 
200 
feet. 
300 
feet. 
400 
feet. 
500 
feet. 
600 
feet. 
20 gallons 
Horse- 
power. 
0.50 
0.75 
1.00 
1.25 
1.50 
Horse- 
power. 
1.00 
1.50 
2.00 
2.50 
3.00 
Horse- 
power. 
1.50 
2.25 
3.00 
3.75 
4.50 
Horse- 
power. 
2.00 
3.00 
4.00 
5.00 
6.00 
Horse- 
power. 
2.50 
3.75 
5.00 
6.25 
7.50 
Horse- 
power. 
3.00 
30 gallons 
4.50 
40 gallons 
50 gallons 
60 gallons 
6.00 
7.50 
9.00 
1 Total head required equals friction head, plus height to be raised, plus loss of head in valves, elbows, 
etc. 
Multiply the theoretical horsepower by 4 for deliveries ' of 30 gallons per 
minute or less and by 3 for deliveries of from 30 to 125 gallons per minute. 
Example. — Required, 40 gallons per minute; maximum distance to be 
pumped, 2 miles up a hill 100 feet in height. 
From first table : Feet. 
Loss in head in pipe line 388 
Vertical height up hill 100 
Estimated loss of head in valves, elbows, etc 20 
Total head -_ 508 
From second table : Horsepower. 
Theoretical horsepower required 5 
Actual horsepower required for engine and pump, three times 
theoretical horsepower 15 
