Abstract
Lifetime prediction of pressurized pipelines in corrosive environments can prove extremely useful to ensure their safe operation and can contribute to significant reduction in maintenance and operational costs.
The concept detailed within this paper is adapted from procedures developed by Electric Power Research Institute USA, using a three level approach, increasing in detail, cost, and complexity, to predict the remaining life of the system. The three levels of assessment are used progressively to predict remaining life or replacement if required. This approach utilizes a number of elements such as definition of the environment and material, together with an understanding of the mode of corrosive attack.
A deterministic model is developed to evaluate the remaining strength of corroded pipelines based on various corrosion conditions. Once introduced, corrosion increases in length, width and depth with exposure period, hence this leads to reduction of remaining strength and the potential delivery capacity of a pipeline. The proposed technique is related to well known methods for estimating the remaining strength of pipelines, however utilizes a simple corrosion model to estimate the remaining life. This can provide a cost effective evaluation of pipeline lifetime assessment without sacrificing the integrity of the system.
