Piping Anti–Corrosion Coating Life Assessment

The pitting corrosion is influential mechanism in determining life of pipes and coatings. Many researches have been conducted on pitting corrosion in the pipelines, resulting in development of some corrosion models. For internal corrosion, there is one main mechanism and it is the uniform corrosion, because dynamic corrosion occurs inside the pipe. However outside the pipe, two corrosion mechanisms are considered for gas pipelines: i) uniform corrosion and ii) pitting corrosion. Effect of uniform corrosion is less than the pitting corrosion, so just pitting corrosion is investigated. Calculating the depth of corroded area is the most important part in this research. This parameter is calculated with two deferent equations for pitting and uniform corrosion. Monte Carlo simulation is used for sampling and calculation of the reliability index. This index is utilized for estimating of reliability. The extended probabilistic analysis framework is applied to a typical gas pipeline.