Open Channels, Pipes & Pumps

Worked: a sewer and a pump

• 24 in concrete pipe, n = 0.013, slope 0.5%, flowing full: R = 0.5 ft, V = 114.3 × 0.630 × 0.0707 = 5.09 ft/s, Q = 5.09 × 3.14 = 16.0 cfs.
• A pump lifting 2 cfs through 80 ft of head at 75% efficiency: 62.4 × 2 × 80 / 0.75 = 13,300 ft-lb/s = 24.2 hp.