Water saving in agriculture sector is a vital issue in countries, which are limited in water resources. To increase the efficiency of water use in irrigation, pressurized systems have been introduced in the recent years. Use of material of high quality is an important factor for achieving econmical performance of these systems. The main objective of this research work was to investigate technical properties of high density poiy - ethylene pipes (HDPE) made in Iran in comparison to international standards.Several sample pipes up to 10 inches in diameter were gathered form different factories and after prepartion were tested according to the international standards. The testing program includes: determination of thickness and diameter, specific gravity, effects on water quality, heat stability, permessible hydrostatic pressure and bursting pressure. A total of 44 samples were investigated in this research. According to the overall results of the experiments, 75% of the samples did not meet the standards for the size - specifications, 30% did not meet the specifications for specific gravity, and 15% had negative effects on water quality. A total of 30% of the samples failed in permissible hydrostatic pressure tests and 30.5% failed in bursting pressure tests. There was no prob1m reltated to heat stability. Some problems were also observed related to quality of manufacturing of the pipes, specially regarding raw materials.
)