Abrasion Effect of Flow on Pipes

Abstract

One of the main factors in determining pipe diameter to design of potable water supplying systems is the flow velocity. The design flow velocity cannot be chosen above a certain value since higher velocities cause deterioration of cement mortar lining, additional management costs and destructive water impact. The flow velocity limits noted in the literature are given in a specific range (0,5-3,0 m/sec). However, the mentioned velocity limits can be increased up to a certain value in systems without pumping by decreasing the pipe diameter. Better quality of cement mortar used in the interior lining of the pipes help to increase capacity and thus the cost of the project can be reduced. In this study, an experimental pipeline model was set up from ductile pipes with cement mortar lining in which high velocities were aimed and a series of experiments were conducted. Experimental set up was composed of ductile pipes with four different diameters (Ø200-300-400-450 mm) and water was recycled from a reservoir to the pipe system and back to the reservoir by pumps. The measured thicknesses from the pipes were compared and the changes on the cement mortar lining were observed.

Analysis of a Water Distribution Network by Newton-Raphson Multivariable Method: A Case of Negligible Minor Losses

“…As water flows through pipes of the network, undesirable noise would be produced if the velocity of the flow is high. Water hammer, cavitation and erosion of the pipe internal surface are also associated with high velocity of flow (Kocyigit et al, 2015). In order to reduce these negative effects, the maximum velocity of flow is limited according to the plumbing code employed.…”

“…The present work utilizes the Darcy-Weisbach approach, together with Colebrook-White and Hagen-Poiseuille equations, and deals with the difficulties brought about by their combinations using the Newton-Raphson method. The flow velocity constraints, suggested by Kocyigit et al (2015), imposed by Uniform Plumbing Code (2016), is used to streamline the network solution set. The velocity constraint imposition was also studied by Suribabu (2012), but his work varied from previous works; firstly, in its preference of Darcy-Weisbach equation to the Hazen-William; secondly, in its choice of head loss/tank elevation minimization objectives as against pipe cost minimization, in the selection of an optimal network solution; and thirdly, in its pipe-selection algorithm.…”