Economic Viability of Gravity-Sustained Pipe-Flow Systems

As the gravity-sustained pipe-flow systems do not require power input, these systems are preferred in comparison to pumping systems. Furthermore, in the absence of moving parts, gravity-sustained systems have greater reliability. For a gently sloping topography the gravitational system involves large pipe diameters. In comparison to a pumping system such a gravitational system may be uneconomical. A review of literature indicated that there is no guideline available for adoption of a gravity-system for such a terrain. In this paper optimal cost functions of various pipe-flow configurations have been investigated to find the conditions under which gravity-sustained systems are economic.