Experimental study of crack behavior in pressurized high-density polyethylene water pipes

Leakage of High-Density Polyethylene pipes are more sensitive to pressure. Longitudinal slits are the most failure in High-Density Polyethylene pipes that occur in water distribution networks. In the present study, longitudinal crack behavior in High-Density Polyethylene pipes is studied by a semi-industrial pilot-scale. Considering that longitudinal slits leakage behavior is a function of variations in leak area that can have elastic or plastic behavior, a new criteria has been introduced for the leak ares variation. The obtained results show that the slits can have plastic behavior even in normal pressures. Also, it is observed that the leakage exponent in the elastic phase is between 0.44 and 1.44 and it increases up to 2 in the plastic phase. Results of this study can be used to estimate the amount of leakage in High-Density Polyethylene pipes and to choose the appropriate leakage reduction strategies. • A new method is presented for evaluating the effective parameters on leakage in longitudinal slits in High-Density Polyethylene pipes including the water temperature. • A new method is presented for estimating discharge coefficient and leakage flow in longitudinal slits in High-Density Polyethylene pipes. • A new method has been introduced to distinguish the elastic or plastic behavior of the longitudinal slits.