Development of limit load solutions for corroded gas pipelines

Pipelines have the highest capacity and are the safest and the least environmentally disruptive means for gas or oil transmission. Recently, failures due to corrosion defects have become of major concern in maintaining pipeline integrity. A number of solutions have been developed for the assessment of remaining strength of corroded pipelines. However, these solutions are known to be dependent on material properties and pipeline geometries. In this paper, a fitness-for-purpose (FFP) type limit load solution for corroded gas pipelines made of X65 steel is proposed. For this purpose, a series of burst tests with various types of machined pits are performed. Finite element simulations are carried out to derive an appropriate failure criterion. Then, further, extensive finite element analyses are performed to obtain the FFP type limit load solution for corroded X65 gas pipelines as a function of defect depth, length and pipeline geometry. (C) 2003 Elsevier Science Ltd. All rights reserved.