Effect of Sandblasting on Tensile Properties, Hardness and Fracture Resistance of a Line Pipe Steel Used in Algeria for Oil Transport

International audienc

Assessment of PIPE for CO 2 transportation using a constraint modified CTOD failure assessment diagram

International audienceFailure Assessment Diagram (FAD) is constraint modified using the assumption that the constraint T stress is proportional to the non-dimensional loading. The constraint modified FAD has been used to compute safety factors associated elliptic defects

Effect of corrosion damage on a pipeline burst pressure and repairing methods

International audienceOn the basis of the calculation of the stress field around the corrosion-damaged areas on the external part of a pipeline used for the transport of hydrocarbons, an analysis of the effect of the level of post-repair burst pressure by composite patches is proposed. This work examines some points of views on the burst pressure standards calculation on real test on pipeline with external corrosion defects. This study divided to three parts. In the first, an inspection is given for a real pipe exhibiting a surface corrosion defect. The corrosion defects were collected and divided into six important defects. The internal pressure has increased to the burst of pipeline. The second part illustrated a numerical study of the defects interaction effect on the safety of pipeline. The third part of this study is showing a finite element analysis of repaired pipe using the composite repair; we will study the effect of the composite sleeve number on the structural integrity of the pipe. The principle of failure assessment (FAD) diagram is described, and particularly, the definition of the non- dimensional applied crack tip loading kr, the non- dimensional net applied stress (or load) Sr or Lr is given. The interest lays in the fact that many pipes defects are scratch or gouge types. In the FAD, results demonstrated that the composite repair method does not affect the interpolation curve and, at the same time, had a slightly effect on the function point

Corrosion Inspection and Recommendation on the Internal Wall Degradation Caused Rupture of 6” Gas Line Pipe

International audienceA sudden leak of 6-inch gas line pipe after being in service for 1 year was observed. The pipe was designed to transport dry gas. The failure had taken place in 6 o’clock position at the stage discharge of the flow process. Specimens from the failed part had taken for laboratory investigation in order to find out the cause of the pipe rupture. Visual and metallographic observations confirmed that the pipe split was due to a crack initiated in circumferential and then turned into longitudinal direction. Sever wall thickness reduction was noticed on the internal pipe surface. SEM observations at the fracture surface revealed features of ductile fracture mode. Corrosion product analysis showed the traces of iron carbonate/iron sulphate. Upon the laboratory analysis, the concluded remarks confirmed that the pipe failed due to the effect of wet fluid (condensate) caused severe wall thickness dissolution resulted in pipe could not stand the continuation at in-service working condition