A leaking buried steel pipeline case study — wall-thickness loss survey, two co-existing root causes (coating disbondment and a cathodic protection deficiency), a corrosion-rate back-calculation, and a B31G remaining-strength assessment used to triage nearby anomalies.
The project brief: a 16 in OD x 0.312 in wall API 5L X52 buried crude oil pipeline began weeping product at the surface after 26 years in service. Framed as this program's baseline failure-analysis project, it walks the excavation, the wall-thickness survey, and a two-part root cause investigation that explains why localized pitting corrosion reached through-wall at one location while the line's overall pressure rating stayed intact everywhere else.
This module works every number a pipeline integrity engineer would actually need: the Barlow's-formula MAOP and minimum wall-thickness check, a DCVG and close-interval potential survey that isolates a coating-shielding condition and a depleted cathodic-protection anode bed as independent root causes, a corrosion-rate back-calculation from measured wall loss, and a modified B31G failure-pressure calculation used to decide which nearby anomalies need immediate repair versus scheduled monitoring. The full worked numbers, complete findings table, and finished remediation plan are part of the unlocked module below.