engleski

Stray current detection on hazardous liquid buried pipelines as a part of pipeline integrity management

Stray current phenomenon that presents a serious threat to hazardous liquid pipeline integrity has been area of concern for pipeline operators since the beginning of the last century. In the intervening century it has only become a bigger problem due to the development of industrial facilities fully followed by growth of underground and aboveground electrical installations. Effects of stray current attack on pipeline may become very serious because current discharge causes enormously rapid and localized corrosion attack that leads to perforation and content leakage. Evaluation of stray current corrosion likelihood is particularly challenging in urban areas due to the multiplicity of possible stray current sources and the complexity of buried infrastructure. For the purpose of this paper a characteristic location in Zagreb municipal area was chosen, where buried high pressure gasline is followed by aboveground DC electric tram rail system. A sufficient number of data were collected by both, classic contact and advanced non-contact potential and current measurement methods. Synchronized simultaneous measurements of pipeline potentials, potential gradients, coupon currents and pipeline currents at multiple points along the pipeline route enable spatial and temporal resolution of stray current action. Evaluated stray current corrosion likelihood based on observed results is a valuable input for overall particular pipeline integrity management. This paper also explores possibilities lowering corrosion risk by applying various mitigation techniques.

corrosion; stray current; pipeline integrity management

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