A triplex booster pumping station lifting water from a clearwell into the distribution system — pump selection, pipe sizing, and NPSH worked from first principles.
The project brief: a municipal water booster station drawing suction from an atmospheric clearwell under a 4 ft suction lift, boosting 1,500 gpm peak-hour demand into a distribution system requiring 65 psi residual pressure. Three 750 gpm pumps (two duty, one standby) deliver firm capacity — full peak demand even with the largest pump down for maintenance — and every fluid-system calculation in this project, from total dynamic head through NPSH, depends on the same suction-side friction numbers.
This module walks the whole project the way a real mechanical design engineer would: suction and discharge pipe sizing driven by NPSH protection, a fully worked total-dynamic-head calculation using Hazen-Williams friction losses, pump power selection from water horsepower to brake horsepower, a worked NPSH-available-versus-required cavitation margin calculation, valve selection and station piping layout, and the mechanical layout considerations — vibration isolation, flexible connectors, shaft alignment — that keep three pumps running reliably side by side. The full worked numbers, complete bill of materials, and finished design reasoning are part of the unlocked module below.