Handbook of Civil Engineering Calculations

Note that if the required pipe size falls between two plotted sizes, the next larger size is
used.
Now in any parallel piping system, the friction-head loss through any branch connect-
ing two common points equals the friction-head loss in any other branch connecting the
same two points. Using Fig. 10 for a 27-in (686-mm) pipe, find the actual friction-head
loss at 8 ft/1000 ft (2.4 m/304.8 m) of pipe. Hence, the total friction-head loss in pipe a is

FIGURE 10. Nomogram for solution of the Hazen-Williams equation for pipes flowing full.

Loss

of

head,

m/304.8

m

Velocity

V,

m/s

Velocity

V,

ft/s

Hazen-WiIliams

Acoefficient

C

Diameter

of

pipe,

mm

Discharge

Q

L/s 1

Diameter

of

pipe,

in

Discharge

Q,

gal/min

Diameter

of

pipe,

ft

Diameter

of

pipe,

m

Loss

of

head,

ft/1000

ft

(1000

S)