feet, then feet

is

the

largest allowable loss per 1,000 feet

a. Requirement.

Determine

the

of pipe. From figure 14, a flow of 25

potable water storage requirement for

gpm and a headloss of 28.5 feet per

the QM depot.

1,000 feet require a minimum diameter

of 1.9 inches.

The next larger size

b. Solution.

From paragraph 9,

available is 2-inch pipe. In the same

Storage requirement = 1/2 (Avg Demand

manner,

the

pipe

size

could

be

x design pop + Large users).

determined for the branch B1 if other

pipe sizes were used or considered on

Design population = Actual population

the main AB.

x capacity factor.

Here, actual population = 50 officers

+ 700 EM = 750 total.

From table 1, for 5,000 people

or

less, the capacity factor is 1.30.

28.5, 2-inch diameter pipe required

on branch B1.

Therefore:

(3) Branch B2.

Flow = 75 gpm,

Design population = 750 (1.30) = 975

length = 300 feet, allowable Hf = 20.7

feet.

Storage requirement 1/2 [(975 x 25) +

47,000] = 35,688 gallons.

The water would probably be stored in

two tanks of approximately equal size.

Naturally

an

actual

distribution

From

figure

14,

3-inch

pipe

is

system would be far more complex than

required.

At this point, the final

the one used in this example.

If

sizes for AB, B1, and B2 have been

there were more sections of main

selected. If a choice of two or more

beyond point B, the headloss from A to

sizes existed for main AB at this

B would have to be added to the

point,

it

would

be

resolved

as

headloss from point B to any other

follows: Since AB is considerably

point in the system.

With this

longer than either B1 or B2, the

exception, the same design steps would

smaller of the possible sizes would be

be

applied

that

were

applied

in

used on AB as this would require

designing

this

water

distribution

considerably less pipe by weight.

system.

First requirement.

Multiple-choice

air from being drawn into the

exercises 1 through 6 are designed to

suction line, at what minimum depth

test your knowledge of common water

in inches should the auction hose

sources.

be located below the water level?

a. 2

c. 4

1. The intake point for a water

b. 3

d. 5

supply system should be as clear

and deep as possible.

To prevent

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