Abstract
Modifications made to a pipeline after initial construction create challenges in selection and application of compatible repair coatings. The installation of coatings is often performed under less than ideal conditions, such as adverse weather. This means that repair coating selection and application frequently occurs under severe time and opportunity constraints.
This case study involves selection and application of wrap-around sleeves applied over electrical leads and strain gauges after their application to the pipeline. Due to the somewhat remote location, supply of coating systems at short notice is constrained and this became an issue when taking advantage of a very brief window of opportunity with winter weather. Approximately a year and a half after initial installation, investigative digs were conducted to determine the cause of strain gauges becoming unserviceable. Significant and unexpected exterior corrosion pitting on the pipe was observed despite maintaining appropriate protective cathodic protection levels. An investigation was conducted and these findings and corresponding remedial actions, together with the impact of unique circumstances associated with actively moving soil on the sloped Right-Of-Way are presented.
