An AC interference study was conducted in 2019 following a utility development project that included constructing a new substation and upgrading approximately 24 km of new AC transmission powerline sections in Alberta, Canada. The study comprised six transmission powerlines owned by one utility and eight […]
The new NACE Standard SP21424-2018 provides a set of simple criteria for assessing the risk of AC corrosion on existing collocations between powerlines and cathodically protected pipelines. However, the task of developing design criteria for new collocations is left to the pipeline operators. This paper […]
The quality of the indirect inspection data is a critical factor in conducting a successful ECDA. It is therefore essential to increase the accuracy of the field data collection, to improve the data processing and to effectively present the results. This paper describes several challenges […]
An AC interference study was conducted in 2015 following the installation of a new 240 kV powerline in a remote area of Alberta, Canada. The calculations indicated severe risk of AC corrosion for the paralleling pipelines and safety hazards for pipeline personnel, especially under fault […]
The 100mV cathodic polarization criterion is being used more extensively on piping in the oil and gas industry which has prompted a discussion on the limits of its use. This paper summarizes the technical literature on the validity of this criterion with respect to elevated […]
Literature dating back to the early 1960’s has shown that AC current can cause corrosion of cathodically protected steel under laboratory conditions. Until recently however, there has been little evidence to suggest that AC corrosion of cathodically protected structures may be of practical concern. In […]
Corrosion of steel by alternating current was investigated as far back as the early 1900’s. These early studies and others in the 1950-60’s indicated that AC corrosion of steel was only a fraction of an equivalent amount of direct current (i.e. less than 1 % […]
