Failure Analysis on Perforation of Girth Weld of a ϕ219 mm×10.5 mm Elbow Pipe

Perforation and leakage failure occurred to a crude oil delivery pipeline full of gasoline at the elbow pipe girth weld position during outage. The macro and micro morphology of the elbow pipe girth weld and working conditions of the elbow pipe were analyzed to find out the reasons of the perforation leakage. The results show that the main reason was the incomplete penetration welding flaw and the minor reason was the corrosion occurring on the surface at the girth weld of the elbow pipe. Therefore, it was suggested that the pipeline welding technology should be improved and the weld quality inspection should be strengthened.