By OGJ editors
HOUSTON, Dec. 5 -- The US Office of Pipeline Safety issued an advisory bulletin to owners and operators of natural gas transmission and hazardous liquid pipelines warning them to consider external corrosion as a possible risk to new pipelines.
The advisory urged pipeline operators to identify and remediate the detrimental effects of stray currents during and after construction.
OPS said, "This action follows the discovery of substantial external corrosion on a newly constructed gas transmission pipeline. The pipeline had been in service a little over 2 years when this unexpected corrosion was revealed by a high-resolution, inline inspection tool.
"The pipe wall pitting was consistent with that caused by underground stray electrical current before a cathodic protection system is installed. In some isolated areas, the pipeline exhibited more than 50% wall loss," the advisory said.
Pipeline operators are urged to "give special attention to a new pipeline's physical location, particularly a location that may subject the new pipeline to stray currents from other underground facilities, including other pipelines, and induced currents from electrical transmission lines, whether aboveground or underground," the advisory said.