Quality Assessment of High Density Polyethylene Pipe in Department of Water Supply and Sewerage

Before fiscal year 068/69, quality of procured pipes was not assessed in Department of Water Supply and Sewerage. Those High Density Polyethylene Pipes might not conform to quality standards and might have been reducing project life. Overall objective of this research was to analyze the quality of HDPE pipe based on laboratory test. All 21 set of test specimen result from different manufacturers have been analyzed’. The collected data were compared to the standards provided by Nepal Bureau of Standards and Metrology, which is NS 402042. This study was based on both qualitative and quantitative information gathered from visual and laboratory tests. NS 40 was published in 1983 and modified in 1985. Since then it is the document that governs Nepalese High Density Polyethylene Pipe industries. HDPE pipes produced from PE 100 are 47.97 percent lighter than PE 63. So, it should be adopted by Nepal Bureau of Standards and Metrology. PE 100 is only 5.27 percent more expensive than PE 63, so department should initiate to reduce the price of High Density Polyethylene Pipe. 2 and 2.5 kg pressure rated pipe are obsolete in procurement. As per the laboratory tests, it was found that Nepalese High Density Polyethylene Pipes met the quality standards. From the test analysis, it was also found that manufacturers intentionally lowered the weight than average and remained in the lower range to avoid failure in the laboratory test. Test certificates as per NS 40 should be mandatory in the frequency set by Nepal Bureau of Standards and Metrology. Office chief and Engineer should be assigned for quality assurance. Length and weight both should be considered in procurement process. Regional laboratory for High Density Polyethylene Pipe testing should be established by DWSS. Transportation cost of High Density Polyethylene Pipe should be based on analysis of transportation from truck up to the nearest road head. High Density Polyethylene Pipe fittings should be purchased based on the detailed drawing of pipeline network and actual need basis.