Editors: | F. Kongoli, H. Dodds, S. Atnaw, T. Turna. |
Publisher: | Flogen Star OUTREACH |
Publication Year: | 2022 |
Pages: | 266 pages |
ISBN: | 978-1-989820-48-3(CD) |
ISSN: | 2291-1227 (Metals and Materials Processing in a Clean Environment Series) |
The protection of pipelines from external corrosion is commonly accomplished by the combination of pipeline coatings with cathodic protection, to protect those portions of the pipeline that are inadequately coated or where the coating contains defects. Defects in pipeline coatings that expose bare steel are termed holidays. Conventional anode resistance formulas that ignore the current and potential distribution on the pipes are inadequate for the modelling of pipelines with holidays. Current and potential distribution must also be considered when modelling multiple pipelines. Factors such as variations in coating quality and stray current interference have an effect on the quality of the cathodic protection system. Another major factor in the design and maintenance of the underground infrastructure (e.g. pipelines, storage tanks, tunnels etc) is the electrical interference (electrical pollution) from power lines, railways and other electrical sources. Traditional resistance formulas are inadequate in modelling these complex interactions. Pipes with coated surfaces can be modelled in several ways. It was assumed in the analysis that the coating is a highly resistive barrier.