Bearing in mind the considerable distances between natural gas fields and consumers’ appliances, transport by gas pipelines remains the most competitive means. These gas pipelines which are generally madeof steel pipes may contain however several types of defects of various originsand which are susceptible to initiate cracks which may grow under some circumstances to such extent as to lead to fracture. Failures of gas pipelines may have serious consequences and may lead to catastrophes from ecological and financial viewpoints. It is therefore interesting to study the defect admissibility so as to maximize safety and minimize exploitation costs through a simplified method based on the Failure Assessment Diagram (FAD). The latter is used in conjunction with Finite Element Analysis (FEM) applied to fracture mechanics to help decision making as to whether a given defect present in a pipe is acceptable or not. Keywords: Cracks, Finite elements, Gas pipelines, FAD.

Abstract

Bearing in mind the considerable distances between natural gas fields and consumers’ appliances, transport by gas pipelines remains the most competitive means. These gas pipelines which are generally madeof steel pipes may contain however several types of defects of various originsand which are susceptible to initiate cracks which may grow under some circumstances to such extent as to lead to fracture. Failures of gas pipelines may have serious consequences and may lead to catastrophes from ecological and financial viewpoints. It is therefore interesting to study the defect admissibility so as to maximize safety and minimize exploitation costs through a simplified method based on the Failure Assessment Diagram (FAD). The latter is used in conjunction with Finite Element Analysis (FEM) applied to fracture mechanics to help decision making as to whether a given defect present in a pipe is acceptable or not.