Experimental Verification of Dents Effect on the Structural Integrity of Pipeline DN 300

Abstract

The stress-strain behaviour of two dents with different depth and shape during the fatigue pressure and burst pressure test is described. The internal inspection carried out on a high-pressure line DN 300 revealed the presence of two dents. Then, the part containing the dents was dug out, removed from operation and the pressure tests were carried out. The stress-strain behaviour was measured with help of nine strain gauges placed on the external pipe surface in the vicinity of dents. The fatigue pressure test simulated fluctuation of pressure, temperature and landslides during operation. During the fatigue pressure test, the profile changes of dents were observed; on the other hand, no fracture occurred. It followed the pressure burst test, the results of which enabled to determine the limit state, burst pressure and position of fracture.