External Corrosion

The external corrosion of pipe lines is controlled by coatings and cathodic protection. External corrosion accounts for about 25% of ruptures on Canadian transmission pipelines. The Canadian Energy Pipeline Association (CEPA) represents the pipeline companies that are responsible for transporting more than 95% of the crude oil and natural gas produced in Canada. CEPA member companies operate more than 100 000 kilometres of pipeline that crisscross Canada, delivering natural gas and petroleum products that fuel homes and industrial output.

External corrosion also accounts for about 15% of upstream pipeline incidents. Recommended practices to control external corrosion on buried or submerged metallic piping systems are described in The Canadian Gas Association's Recommended Practice OCC-1-1996.