This paper describes the challenge of integrating specific types of ECDA indications, such as AC enhanced corrosion (ACEC) and DC interference (DCI), under the prioritization criteria recommended by NACE RP0502-2002.
Starting from the observation that the risk of corrosion does not always increase with the size of the holiday, the paper analyzes the interaction of up to four complementary ECDA indications (i.e. CIPS, DCVG, ACEC and DCI), with and without prior history of corrosion, as a function of their severity.
New concepts, such as “distributed indication” and “relevant indication” are introduced in order to establish the location of the direct examinations, where the indication affects entire sections of line (i.e. 10 km of line subject to severe ACEC).
Simple rules are proposed for integrating these multiple ECDA indications m matrix type prioritization tables. The paper also includes an example of using these tables to prioritize a combination of three indications without prior history of corrosion (i.e. moderate DCVG in conjunction with a severe DCI and a severe CIPS indication).