STUDY OF DEFECT ADMISSIBILITY IN GAS PIPELINES BASED ON FRACTURE MECHANICS

Bearing in mind the considerable distances between natural gas fields andconsumers’ appliances, transport by gas pipelines remains the most competitivemeans. These gas pipelines which are generally made of steel pipes may containhowever several types of defects of various origins and which are susceptible toinitiate cracks which may grow under some circumstances to such extent as tolead to fracture. Failures of gas pipelines may have serious consequences andmay lead to catastrophes from ecological and financial viewpoints. It istherefore interesting to study the defect admissibility so as to maximize safetyand minimize exploitation costs through a simplified method based on theFailure Assessment Diagram (FAD). The latter is used in conjunction withFinite Element Analysis (FEM) applied to fracture mechanics to help decisionmaking as to whether a given defect present in a pipe is acceptable or not.