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