Problem Summary
Anomaly Description:
The 14” Crude line that supplies to the refinery was inspected and it was noted that severe external pitting corrosion was found on the contact areas where the pipe meets the concrete sleepers. 178 support sections were identified with 27 of them having major wall thinning. Major findings had wall losses of approximately 70 percent.
2,7mm wall left from an original 9,52mm.
Root causes:
Improper design of sleeper support without consideration of any sacrificial wear material, for example a metal wear pad. The pipe is positioned directly on a 20mm diameter round bar. Because of the vibration and movement of the pipeline over the years, it has started eating away at the localised spots where the pipe meets the round bar.
Integrity concerns:
Further deterioration could lead to possible leaks on the pipeline. The pipeline supplies crude oil to the refinery which could result in major downtime and pose fire and environmental hazards. In major findings it is reported that the line is operating below the design minimum thickness due to design pressure.


