The Resistance of Advanced Pipeline Coatings to Penetration and Abrasion by Hard Rock

The resistance to rock penetration and abrasion damage of four advanced pipeline anti-corrosion coatings on buried steel linepipe was quantified by means of controlled pipe burial tests. Production-coated steel linepipes were buried in three different gradations of crushed hard rock, and a Caterpillar 966D wheel loader was driven directly over the buried pipes twice daily for 12 consecutive days. Subsequent excavation and inspection of the pipes showed that the coatings experienced progressively more damage (quantified by the number of holidays) with increase in rock size and progressively less damage with increase in coating thickness. A quantitative relationship between coating damage and coating thickness was defined for the two larger rock sizes.