Page 12 - Reliability and Maintainability of In service Pipelines

Introduction Chapter

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Abstract
This chapter introduces the most common type of pipelines used in industry. Pipes
categorized based on their material type and their areas of usage as well as their
overall characteristics are mentioned.
At the first step of reliability analysis and service life prediction of pipelines, it is
necessary to gain knowledge about the design principles and loads affecting buried
pipes. The performance criteria for in-service loads are introduced in this chapter as
ultimate limit state and serviceability limit state. Flexural and shear failures are the
two main ultimate limit states that are considered in design and assessment.
Serviceability limit states may be measured by cracking condition. These criteria
should be met for a pipeline to be safe and in-service. This chapter reviews the loads
and stresses acting on pipelines. The stress formulations will be used later on in
reliability analysis, where the limit state function (failure mode) is checked.
Material deterioration is the most common form of pipeline deterioration and is a
matter of concern for both the strength and durability functions. How to incorporate
the effect of corrosion in the structural analysis of a pipeline is of practical
importance. This chapter outlines the corrosion formulation for different pipe
types. This knowledge will be used in Chapter 2 for suggesting efficient methods for
inspection and maintenance of in-service pipelines as well as in Chapter 4 for
formulation of failure function(s) in time-dependent reliability analysis methods.

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Reliability and Maintainability of In-Service Pipelines. DOI: https://doi.org/10.1016/B978-0-12-813578-5.00001-9
© 2018 Elsevier Inc. All rights reserved.