Selection and Optimization of Test Points to Adequately Verify the Performance of Cathodic Protection Systems

Abstract It is common practice for hazardous product pipeline operators to schedule physical cathodic protection (CP) pipe-to-soil (p/s) potential measurements from every available test post on all pipelines annually. Historical data confirms that when the cathodic system output remains consistent; protection levels will typically not vary significantly from year to year. Such conventional annual CP survey practice is not mandated by North American standards or codes but is rather part of the integrity management process. The practice of annual conventional test point measurement carries a high labor cost and may only achieve marginal value in the performance assessment of a cathodic protection system and overall pipeline integrity. Effective evaluation of annual CP system performance can be accomplished without necessarily collecting data from every test post, every year. It can be achieved by taking a proactive/performance based external corrosion prevention (ECP) management approach that is aligned with other pipeline integrity programs, and utilizes all available relevant information. This paper presents a concept and methodology on optimising cathodic protection field data collection in alignment with a comprehensively progressive and proactive performance based ECP program to maintain pipeline safety.