Estudo comparativo entre metodologias de dimensionamento econômico de adutoras.

Abstract

The water pipelines are the main canalizations of a supplying system destined to lead water among the units that precede the distribution network. In intention of getting more economy on investment and operation water pipelines costs in the water supply, methodological alternatives to the classic formula of Bresse for the sizing of these systems are presented. Two methods are presented: the first one is based on linear variation of tubes prices with its diameters and the other is based on variation of tubes prices with its weights. The results of the sizing had been compared with the results gotten through the method of the real evaluation of the costs, in which the excellent diameter is gotten among a range of commercially available diameters. Through four practical applications, was demonstrated the validity of both methods. In a studied case of Acaua water pipeline in the state of Paraiba, had been still tested three different cases as alternative of array for the pipelines in parallel. In case 1, an only tube would form the water pipeline and installed in year 2000 to function per twenty years. In case 2, two tubes in parallel would form the pipeline, where the first one would be installed in year 2000, to function per twenty years, and the second one would be installed in year 2010, to function per ten years. In case 3, three tubes in parallel would form the pipeline, where the first one would be installed in year 2000, to function per twenty years, and the second one would be installed in year 2010, to function per ten years, and the third would be installed in year 2015, to function per five years. Was concluded that, for case 3, tested for two materials, ductile iron and PRFV, was gotten more reduced total costs. The PRFV, when compared with the ductile iron, in relation to the costs, it was demonstrated more economic.