Example 4.13: Water flows through a smooth pipe having inside diameter 0.5 in at a velocity of 2 ft/s. The pipe is 1000 ft in length. Piping arrangement contains a fully-open, a 3/4-open, a 1/2-open, and a 1/4-open gate valves. Use equivalent length of valves, Le, to estimate the total pressure drop. Use the following information:
Density = 62.37 lb/ft3; viscosity = 7.53 ´ 10-4 lb/(ft·s)
Solution:
Calculate Re:
Friction factor for smooth pipe f = 0.0086.
Obtain equivalent lengths of the valves using Figure 4.5
Total equivalent length Le = 52.35 ft.
Calculate the effective length of the pipe as the sum of the pipe length and the equivalent lengths of fittings and valves.
Calculate frictional loss hf
If the points in consideration are at the same elevation, then pressure drop is