In this article, (and video above), we calculate the source pressure to move water through a 3″ ID steel pipe by using the Darcy-Weisbach equation and the Friction Factor Diagram provided in the PE Handbook. This question forms part of the Hydraulics and Hydrology section of the PE Exam and was created and solved by Engineer in training, Enrique Ivers.
Question:
Water needs to be transferred from a settling basin to a treatment facility. The distance from the basin to the facility is 500 feet, and the facility is at an elevation 25 feet higher than the basin. The specified capacity is 100 gallons per minute with at least 20psig of pressure at the facility.
If a 3-inch ID steel pipe is used, how much pressure needs to be provided at the basin, in psig? The Reynolds number is determined to be 2 x 10^5 and the specific roughness per the pipe manufacturer is 0.0002 ft.