Determination of Limit Load Solution for the Remaining Load-Carrying Capacity of Corroded Pipelines

Abstract

The evaluation of pipelines having external corrosion defect and their remaining load-carrying capacity is a concern which becomes important in energy industry, especially with the increasing operating pressures and the consequences which can occur following the bursting of these pipelines. A lower bound analytical solution for the prediction of the burst pressure of pipelines is proposed. This solution is based on the approach of plastic-instability criterion in terms of material strain-hardening exponent of internally pressurized corroded pipelines. The suggested solution is evaluated by using database comprising more than 100 carried out tests of pipelines with or without corrosion defects. This database is collected from the literature and covers the majority of steel materials as well as the various standard sizes. The accuracy of the proposed solution is compared with B31.G method and its improved version B31.G Mod by using statistical analyses in terms of average error and its correspondent standard deviation. The proposed solution is accurate than B31.G and modified B31.G methods that are conservative and provide in some cases of middle and high strength material an overestimated burst pressure predictions.