Qualitative and Hydraulic Comparison of Cement Asbestos and Polyethylene Pipes using WaterGEMS Software

ABSTRACT: Pipe material selection in drinking water networks is amongst the major factors of public health and well-being. Pipe of an inappropriate material can result in the infection of water or waste of water sources. Hence, conducting technical and hydraulic comparisons of pipes such as comparing roughness and its effect on pressure, velocity, tracking, retention time and tracking chlorine concentration are very significant in providing appropriate quality of water. Accordingly, in present study, water supply network simulation of area 2, Karaj Province is carried out by WaterGEMS model to examine polyethylene (PE) and cement asbestos pipes using instable hydraulic methods similar to what happens in the network which based on the evaluation of the above issues during the study, it is observed that pressure in polyethylene pipes is about 0.5 to 3m over the pressure in asbestos pipes which is caused by the reduction of friction loss by 0.2 to 0.6m in polyethylene pipes compared to asbestos pipes. Also, economic reviews show that purchase cost of polyethylene (ranging from 150mm or further) is more than asbestos pipes which leads to an increase in primary investment costs, but executive costs of the polyethylene pipes is less than that of asbestos pipes.