Making use of external corrosion defect assessment (ECDA) data to predict DCVG %IR drop and coating defect area

Nik N. Bin Muhd Noor; Keming Yu; Ujjwal Bharadwaj; Tat-Hean Gan

doi:10.1002/maco.201810085

Making use of external corrosion defect assessment (ECDA) data to predict DCVG %IR drop and coating defect area

Materials and Corrosion ◽

10.1002/maco.201810085 ◽

2018 ◽

Vol 69 (9) ◽

pp. 1237-1256 ◽

Cited By ~ 2

Author(s):

Nik N. Bin Muhd Noor ◽

Keming Yu ◽

Ujjwal Bharadwaj ◽

Tat-Hean Gan

Keyword(s):

Corrosion Defect ◽

Ir Drop ◽

Defect Assessment ◽

Defect Area ◽

Coating Defect ◽

External Corrosion

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Experimental Database for Corroded Pipe: Evaluation of RSTRENG and B31G

Volume 2: Integrity and Corrosion; Offshore Issues; Pipeline Automation and Measurement; Rotating Equipment ◽

10.1115/ipc2000-190 ◽

2000 ◽

Cited By ~ 13

Author(s):

Duane S. Cronin ◽

Roy J. Pick

Keyword(s):

Tensile Tests ◽

Line Pipe ◽

Experimental Database ◽

Corrosion Defect ◽

Defect Assessment ◽

Simple Geometry ◽

Corrosion Defects ◽

Failure Predictions ◽

External Corrosion ◽

Assessment Procedures

The evaluation and development of the current corrosion defect assessment procedures for pipelines has been based on experimental burst tests of line pipe. In these tests, external corrosion has often been simulated with machined defects of simple geometry. As a result, assessment procedures which model the corrosion defect geometry with only a few parameters, such as ASME B31G, show reasonable agreement with the experiments. However, the degree of conservatism in these assessment methods is undefined when they are applied to complex corrosion defects. The authors have burst over 40 pipes removed from service due to corrosion defects. All corrosion defects on each pipe were measured in detail and the material properties were determined from tensile tests. The currently accepted assessment procedures for corroded line pipe (B31G and RSTRENG) have been applied to the database. The degree of conservatism in these procedures is quantified and a statistical model for the failure predictions is proposed.

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Finite Element Analysis of Complex Corrosion Defects

Computational Mechanics: Developments and Applications ◽

10.1115/pvp2002-1288 ◽

2002 ◽

Cited By ~ 1

Author(s):

Duane S. Cronin

Keyword(s):

Finite Element Analysis ◽

Finite Element ◽

Burst Pressure ◽

Uniaxial Tensile ◽

Element Analysis ◽

Internal Corrosion ◽

Corrosion Defect ◽

Elastic Plastic ◽

Defect Assessment ◽

Corrosion Defects

Aging gas and oil transmission pipeline infrastructure has led to the need for improved integrity assessment. Presently, external and internal corrosion defects are the leading cause of pipeline failure in Canada, and in many other countries around the world. The currently accepted defect assessment procedures have been shown to be conservative, with the degree of conservatism varying with the defect dimensions. To address this issue, a multi-level corrosion defect assessment procedure has been proposed. The assessment levels are organized in terms of increasing complexity; with three-dimensional elastic-plastic Finite Element Analysis (FEA) proposed as the highest level of assessment. This method requires the true stress-strain curve of the material, as determined from uniaxial tensile tests, and the corrosion defect geometry to assess the burst pressure of corrosion defects. The use of non-linear FEA to predict the failure pressure of real corrosion defects has been investigated using the results from 25 burst tests on pipe sections removed from service due to the presence of corrosion defects. It has been found that elastic-plastic FEA provides an accurate prediction of the burst pressure and failure location of complex-shaped corrosion defects. Although this approach requires detailed information regarding the corrosion geometry, it is appropriate for cases where an accurate burst pressure prediction is necessary.

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