Abstract
This paper addresses the hydraulic and economic optimum design of a horizontal pipeline with equally spaced similar pumping units. A single design formula is presented for application to all turbulent flow regimes on the basis of Swamee-Jain's explicit friction formula and accounting for levelized annual costs of both pumping energy and pipes. Though the design formula is implicit, its convergence characteristics are such that it requires only a short trial and error procedure of two steps. A nondimensional minimum-cost design chart is also provided. The chart covers a wide range of conditions and cases that might occur in practice. Three numerical examples are presented to illustrate the use of both the design formula and the design chart in solving actual field problems.