Challenges for the development of nondestructive testing (NDT) in pipeline inspection

Compared with all other technologies pipelines are the most technical save facilities to transport oil, gas and derivatives of them. Worlwide more than 3 millions of km are in use and every year an increase in the range of 25000 km pipelines are to observe. However, like each technical component, also a pipeline suffers under aging phenomena like corrosion and fatigue. In order to avoid catastrophic failure and damage of human beings and environment pipelines are regularly inspected by using NDT. Describing the state of the art in pipeline inspection applying in-line tools, so called 'intelligent pigs', recent developments are presented. The special emphasis of the contribution is on crack detection and sizing an inspection task with increasing importance.