Pipeline failures due to volumetric defects

Abstract

Safety is the main aspect to be considered in the design and operation of transport and gas distribution systems. International regulations address this issue to minimize negative events in the community. The first part of this work illustrates typical defects that can be found in pipes, and describes several mathematical models, of increasing difficulty, that determine the pressure of failure associated with volumetric defects (which are usually caused by corrosion of the pipe steel). We analyze different methods of evaluation currently available and suggest recommendations for their application to pipelines made of different steels. As case studies, we analyze defects which have been a priori qualified as very serious, that belong to pipelines of the province of Cordoba, in Argentina. Taking into account the characteristics of construction and operation of the pipelines under analysis, we compare the failure pressures provided by different methods of evaluation with operating pressures. Finally, we compare the levels of defect evaluation in terms of their complexity and predicted results.