Problem 4.8.2
Water flows through a 0.5-in
diameter smooth-pipe at 2 feet per second.
The pipe is 1000 feet long.
Piping arrangement contains one fully-open, one ¾-open, one ½-open and
one ¼-open gate valves. Estimate total pressure drop in the system, when pressure drop of
valves is expressed as, Le equivalent
pipe.
Solution:
Reynolds number is calculated
as 6.906 times 103. Friction
factor is read as 0.0086. Frictional
loss through fittings and valves is given in Figure 4-11 (Equivalent length of
pipe fittings and valves). Le values are 0.35, 2, 10,
and 40 for gate valves that are fully-open, ¾-open, ½-open, and ¼-open,
respectively. Equivalent length for the
valves in the piping network is 52.35 feet.
Combined length is 1000 feet plus 52.35 feet or 1052.35 feet. Frictional head loss is 54.01 foot
pound-force per pound-mass. Pressure drop is 23.4 psi.