Ian Partridge: About the Author
TWI

A few years ago, TWI investigated a corrosion failure in a 30 inch crude oil pipeline that regrettably led to an explosion and fire, and the death of several operating personnel. The pipeline was designed to ASME B31.4 and the investigation found that corrosion resulted from the break-down of the external coating. The exposed area of pipe was too large for the cathodic protection system. Pitting corrosion initiated at several locations that coalesced over a large area to cause failure by rupture. The lost production from this failure was 300,000 bbl/d. The corrosion in this pipeline was not detected before failure. However, if corrosion is found in service pressure equipment, there are safe guidelines available for inspection engineers to assess the fitness-for-service (FFS) of corrosion damage.