scholarly journals Structural Integrity of Steel Pipeline with Clusters of Corrosion Defects

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 852
Author(s):  
Maciej Witek
Keyword(s):  
Structural Integrity ◽  
Burst Pressure ◽  
Steel Pipeline ◽  
Axial Excitation ◽  
Transmission Pipeline ◽  
Corrosion Defects ◽  
Pipeline Failure ◽  
Corrosion Pits ◽  
Evaluation Of Data ◽  
Flux Leakage

The main goal of this paper is to evaluate the burst pressure and structural integrity of a steel pipeline based on in-line inspection results, in respect to the grouping criteria of closely spaced volumetric surface features. In the study, special attention is paid to evaluation of data provided from the diagnostics using an axial excitation magnetic flux leakage technology in respect to multiple defects grouping. Standardized clustering rules were applied to the corrosion pits taken from an in-line inspection of the gas transmission pipeline. Basic rules of interaction of pipe wall metal losses are expressed in terms of longitudinal and circumferential spacing of the features in the colony. The effect of interactions of the detected anomalies on the tube residual strength evaluated according to the Det Norske Veritas Recommended practice was investigated in the current study. In the presented case, groups of closely-spaced defects behaved similarly as individual flaws with regard to their influence on burst pressure and pipeline failure probability.

An investigation of the effects of corrosion on the fatigue strength of AlN axle steel

2008 ◽  
Vol 222 (2) ◽  
pp. 129-143 ◽  
Author(s):  
S Beretta ◽  
M Carboni ◽  
A Lo Conte ◽  
E Palermo
Keyword(s):  
Fatigue Strength ◽  
Corrosion Fatigue ◽  
Structural Integrity ◽  
Point Of View ◽  
Fatigue Properties ◽  
Test Results ◽  
Surface Corrosion ◽  
Corrosion Defects ◽  
Corrosion Pits ◽  
Technical Recommendations

Corrosion fatigue is an important topic in the evaluation of the structural integrity of railway axles. In fact, several recent axle failures have been attributed to the presence of corrosion pits and axle surface corrosion. Despite the importance of this issue, existing EN standards do not precisely quantify the effect that corrosion or corrosion-fatigue might have on the fatigue strength of a railway axle. Consequently, there is a need to have a better understanding of this problem. In this paper, two main lines of research have been adopted with a view to investigating the issues regarding the corrosion fatigue properties of AlN steel. The first line of research assesses the morphology and the statistical distribution of corrosion defects present on the surface of retired axles together with the detrimental effect of the defects detected on the in-air fatigue strength of AlN steel. The second line of research examines the fatigue properties of AlN steel in the presence of artificial rainwater. The results of the analysis show that the corrosion typically found on axles is significant from a point of view of fatigue properties and that the fatigue life of AlN steel is strongly affected by the presence of a mildly corrosive substance like rainwater. Fatigue test results are consistent with the fatigue strength reduction outlined in the BASS technical recommendations.

Pressure Test Planning to Prevent Internal Corrosion by Residual Fluids

2012 ◽  
Author(s):  
Trevor Place ◽  
Greg Sasaki ◽  
Colin Cathrea ◽  
Michael Holm
Keyword(s):  
Structural Integrity ◽  
Large Diameter ◽  
Long Distance ◽  
Internal Corrosion ◽  
Pressure Testing ◽  
Practical Strategy ◽  
Leak Testing ◽  
Pressure Test ◽  
Transmission Pipeline ◽  
Pipeline Project

Strength and leak testing (AKA ‘hydrotesting’, and ‘pressure testing’) of pipeline projects remains a primary method of providing quality assurance on new pipeline construction, and for validating structural integrity of the as-built pipeline [1][2][3]. A myriad of regulations surround these activities to ensure soundness of the pipeline, security of the environment during and after the pressure testing operation, as well as personnel safety during these activities. CAN/CSA Z662-11 now includes important clauses to ensure that the pipeline designer/builder/operator consider the potential corrosive impacts of the pressure test media [4]. This paper briefly discusses some of the standard approaches used in the pipeline industry to address internal corrosion caused by pressure test mediums — which often vary according to the scope of the pipeline project (small versus large diameter, short versus very long pipelines) — as well as the rationale behind these different approaches. Case studies are presented to highlight the importance of considering pressure test medium corrosiveness. A practical strategy addressing the needs of long-distance transmission pipeline operators, involving a post-hydrotest inhibitor rinse, is presented.

Steel pipeline testing using magnetic flux leakage method

2008 ◽  
Author(s):  
Xiang Li ◽  
Xunbo Li ◽  
Liang Chen ◽  
Guangxu Qin ◽  
Peifu Feng ◽  
...  
Keyword(s):  
Magnetic Flux ◽  
Magnetic Flux Leakage ◽  
Steel Pipeline ◽  
Flux Leakage

Failures of Pipelines

2021 ◽  
pp. 531-556
Author(s):  
A. Hudgins ◽  
C. Roepke ◽  
B. James ◽  
B. Kondori ◽  
B. Whitley
Keyword(s):  
North America ◽  
Failure Analysis ◽  
Management Practices ◽  
Failure Modes ◽  
Degradation Mechanisms ◽  
Transmission Pipeline ◽  
Integrity Management ◽  
Pipeline Failure ◽  
Pipeline Failures

Abstract This article discusses the failure analysis of several steel transmission pipeline failures, describes the causes and characteristics of specific pipeline failure modes, and introduces pipeline failure prevention and integrity management practices and methodologies. In addition, it covers the use of transmission pipeline in North America, discusses the procedures in pipeline failure analysis investigation, and provides a brief background on the most commonly observed pipeline flaws and degradation mechanisms. A case study related to hydrogen cracking and a hard spot is also presented.

Effects of Detector Dynamics on Magnetic Flux Leakage Signals From Dents and Gouges

2012 ◽  
Author(s):  
Lynann Clapham ◽  
Vijay Babbar
Keyword(s):  
Magnetic Flux ◽  
Pipe Wall ◽  
Magnetic Flux Leakage ◽  
Signal Loss ◽  
Magnet System ◽  
High Speeds ◽  
Study Results ◽  
Dynamic Case ◽  
Corrosion Defects ◽  
Flux Leakage

The current study was designed to model the dynamic effects of detector ride and magnet liftoff on Magnetic Flux Leakage (MFL) signals from dents as well as gouges that have significant denting. The MFL tools have long been used for the detection and sizing of corrosion defects. This is comparatively straightforward for a number of reasons, one of which is that the MFL detector assembly can ride relatively smoothly along the inner pipe wall surface. This is not the case when significant denting is present, since the dent presents a perturbation in the pipe wall that can cause liftoff of the detector or magnet system. Since the tool travels at relatively high speeds down the pipe, the dent itself can cause the detector to lose contact with the trailing half of the dent. In addition, the magnet pole piece may experience partial liftoff as it traverses the dent, thus causing a change in the local flux density. In this study results from ‘static’ measurements are compared with a dynamic case in which detector liftoff is simulated through modeling and experiment. Results are discussed regarding the severity of MFL signal loss at the trailing edge of the defect as a result of detector liftoff. The effect of partial liftoff of the magnet as it passes over the dent is also examined. Magnet liftoff is found to increase the local magnetic flux near the liftoff region, causing the MFL signal from the dent wall to increase rather than decrease in the vicinity of magnet liftoff region.

Validating ILI Accuracy Using API 1163

2014 ◽  
Author(s):  
Lucinda Smart ◽  
Harvey Haines
Keyword(s):  
Burst Pressure ◽  
Metal Loss ◽  
Internal Corrosion ◽  
Know How ◽  
Pressure Calculation ◽  
Loss Data ◽  
Pipeline Segment ◽  
External Corrosion ◽  
Corrosion Pits

It is important to validate the accuracy of in-line inspection (ILI) tools to know how many excavations are needed to maintain the integrity of a pipeline segment. Performing sufficient excavations is important to ensure there are no defects left in the pipeline that have even a remote chance of failure. In some cases additional excavations may be necessary to ensure safety where in other cases no excavations may be necessary. This paper looks at using spatially recorded metal-loss data collected “in-the-ditch” to measure the accuracy of ILI tool results. Examples of spatial in-ditch data are laser scans for external corrosion and UT scans for internal corrosion. Spatially mapped metal loss, because all of the corrosion area is mapped, has the advantage of allowing more comparisons to be made for a given corrosion area and also allows the interaction among corrosion pits to be studied for examining burst pressure calculation accuracy. From our studies we find the depth error for shallow corrosion 10%–20% wt deep is often not representative of deeper corrosion in the same pipeline and the interaction criteria for ILI tools needs to be larger than the interaction criteria for in-ditch data. Examples are shown with these types of results, and by interpreting the results in conjunction with API 1163, certain ILI runs are shown that require no excavations where others may require additional excavations than suggested by normal +/−10% wt ILI data.

Structural integrity analysis of pipelines with interacting corrosion defects by multiphysics modeling

2019 ◽  
Vol 97 ◽  
pp. 91-102 ◽  
Author(s):  
Elder Soares ◽  
Vivianne Marie Bruère ◽  
Silvana M.B. Afonso ◽  
Ramiro B. Willmersdorf ◽  
Paulo R.M. Lyra ◽  
...  
Keyword(s):  
Structural Integrity ◽  
Multiphysics Modeling ◽  
Corrosion Defects ◽  
Integrity Analysis
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