Improved Pipeline Dent Integrity Management

2016 ◽  
Author(s):  
Sanjay Tiku ◽  
Amin Eshraghi ◽  
Vlad Semiga ◽  
Luis Torres ◽  
Mark Piazza
Keyword(s):  
Numerical Simulation ◽  
Fatigue Life ◽  
Fatigue Testing ◽  
Assessment Model ◽  
Third Party ◽  
Operating Pressure ◽  
Integrity Assessment ◽  
Integrity Management ◽  
Further Development ◽  
Dent Depth

Pipeline dents can be developed from the pipe resting on rock, a third party machinery strike, rock strikes during backfilling, amongst other causes. The long-term integrity of a dented pipeline segment depends upon parameters including pipe geometry, indenter shape, dent depth, indenter support, secondary features, and pipeline operating pressure history at and following indentation. US DoT and other standards include dent repair and remediation criteria broadly based upon dent depth, dent location (top or bottom side), pressure cycling (liquid or gas), and dent interaction with secondary features (weld, corrosion, cracks). These criteria are simple and easily applied, however, they may not direct maintenance appropriately and be overly conservative or, in some cases, unconservative. Previous IPC papers have discussed the full-scale dent fatigue testing and dent modelling efforts to support integrity management criteria development by collecting material and structural response during dent formation and pressure loading. The present paper will present the results of this extensive dent structural and fatigue life numerical simulation program using a validated finite element (FE) analysis process. The paper describes the numerical simulation technique, as well as, the development of the novel engineering tool for integrity management, eliminating the need for numerical simulation of individual dent features to assess the relative integrity threat they pose. The development of the engineering tool presented in this paper considers the dent formation, re-rounding and through life response to pressure fluctuations to evaluate the fatigue life of dent features. The results of these analyses are used to develop fatigue life trends based on dent shape, restraint condition and operating pressure. These trends were used to develop models to predict dent relative severity and life based upon ILI inspection dent shape data for single peak dents. Dent shape has also been used to determine the restraint condition of a dent and its influence on the dent feature fatigue life. The tools were developed to address many of the uncertainties inherent in existing regulatory repair and remediation criteria. Current and future applications of the integrity assessment model are described along with recommendations for further development and testing to support pipeline integrity management, industry guidelines and standards. The results of this research will be of use in improving integrity management decisions and support further development of industry guides and standards. As such the information presented in this paper will be of interest to pipeline operators, integrity management specialists, in-line inspection (ILI) organizations and regulators. The recommendations presented in this paper may be used to influence the direction of pipeline standards in their direction in the disposition of dent features.

Dent Assessment and Management: API Recommended Practice 1183

2020 ◽  
Author(s):  
Aaron Dinovitzer ◽  
Sanjay Tiku ◽  
Mark Piazza
Keyword(s):  
Model Development ◽  
Complex Function ◽  
Assessment Tools ◽  
Third Party ◽  
Operating Pressure ◽  
Operating Life ◽  
Limit States ◽  
Integrity Assessment ◽  
Integrity Management ◽  
Dent Depth

Abstract Pipeline dents can be developed from the pipe resting on rock, a third-party machinery strike, rock strikes during backfilling, amongst other causes. The long-term integrity of a dented pipeline segment is a complex function of a variety of parameters including pipe geometry, indenter shape, dent depth, indenter support, secondary features, and pipeline operating pressure history at and following indentation. In order to estimate the safe remaining operating life of a dented pipeline, all of these factors must be considered and guidelines for this assessment are not available. US DOT regulations (49 CFR 192 and 195) include dent repair and remediation criteria broadly based upon dent depth, dent location (top or bottom side), pressure cycling (liquid or gas), and dent interaction with secondary features (weld, corrosion, cracks). The criteria defined above are simple to use, however, they may not direct maintenance to higher risk dent features and be overly conservative or, in some cases, unconservative. PRCI, USDOT, CEPA and other full-scale testing, finite element modelling and engineering model development research has been completed to evaluate the integrity of pipeline dents. These results have demonstrated trends and limits in dent behavior and life that can improve on existing codified and traditional treatment of dents. With these research results a guideline for dent management can be developed to support operators develop and implement their pipeline integrity management programs. This paper provides an overview of the newly developed API recommended practice for assessment and management of dents (RP 1183). The RP considers dent formation strain, failure pressure and fatigue limit states including the effects of coincident features (i.e. welds, corrosion, cracks and gouges). This paper will focus on how pipeline operators can derive value from this step change in integrity management for dents. The paper describes the basis for the dent screening and integrity assessment tools included in the RP. This RP provides well founded techniques for engineering assessment that may be used to determine the significance of dent features, if remedial actions are required and when these actions should be taken.

Full Scale Cyclic Fatigue Testing of Dented Pipelines and Development of a Validated Dented Pipe Finite Element Model

2012 ◽  
Author(s):  
Sanjay Tiku ◽  
Vlado Semiga ◽  
Aaron Dinovitzer ◽  
Geoff Vignal
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Fatigue Testing ◽  
Complex Function ◽  
Element Model ◽  
Full Scale ◽  
Assessment Model ◽  
Integrity Assessment ◽  
Operational Life ◽  
Integrity Management

Dents in buried pipelines can occur due to a number of potential causes; the pipe resting on rock, third party machinery strike, rock strikes during backfilling, amongst others. The long-term integrity of a dented pipeline segment is a complex function of a variety of parameters, including pipe geometry, indenter shape, dent depth, indenter support, pressure history at and following indentation. In order to estimate the safe remaining operational life of a dented pipeline, all of these factors must be accounted for in the analysis. The paper discusses the full-scale dent testing being completed to support the development of pipeline integrity management criteria and is a continuation of the work discussed in previous IPC papers [1,2]. The material and structural response of the pipe test segments during dent formation and pressure loading has been recorded to support numerical model development. The full scale experimental testing is being completed for pipe test specimens in the unrestrained and restrained condition using different indentation depths and indenter sizes. The dents are pressure cycled until fatigue failure in the dent. This paper presents typical data recorded during trial including indentation load/displacement curves, applied pressures, strain gauges along the axial and circumferential centerlines, as well as dent profiles. The use of the full-scale mechanical damage test data described in this paper in calibrating and validating a finite element model based integrity assessment model is outlined. The details of the integrity assessment model are described along with the level of agreement of the finite element model with the full scale trial results. Current and future applications of the integrity assessment model are described along with recommendations for further development and testing to support pipeline integrity management.

Pressure Cycling Monitoring Helps Ensure the Integrity of Energy Pipelines

2010 ◽  
Author(s):  
Peter Song ◽  
Doug Lawrence ◽  
Sean Keane ◽  
Scott Ironside ◽  
Aaron Sutton
Keyword(s):  
Fatigue Life ◽  
Pipeline System ◽  
Outer Diameter ◽  
Operating Pressure ◽  
Potential Growth ◽  
Integrity Assessment ◽  
Pressure Cycling ◽  
Pressure Cycle ◽  
Primary Focus ◽  
Pump Stations

Liquids pipelines undergo pressure cycling as part of normal operations. The source of these fluctuations can be complex, but can include line start-stop during normal pipeline operations, batch pigs by-passing pump stations, product injection or delivery, and unexpected line shut-down events. One of the factors that govern potential growth of flaws by pressure cycle induced fatigue is operational pressure cycles. The severity of these pressure cycles can affect both the need and timing for an integrity assessment. A Pressure Cycling Monitoring (PCM) program was initiated at Enbridge Pipelines Inc. (Enbridge) to monitor the Pressure Cycling Severity (PCS) change with time during line operations. The PCM program has many purposes, but primary focus is to ensure the continued validity of the integrity assessment interval and for early identification of notable changes in operations resulting in fatigue damage. In conducting the PCM program, an estimated fatigue life based on one month or one quarter period of operations is plotted on the PCM graph. The estimated fatigue life is obtained by conducting fatigue analysis using Paris Law equation, a flaw with dimensions proportional to the pipe wall thickness and the outer diameter, and the operating pressure data queried from Enbridge SCADA system. This standardized estimated fatigue life calculation is a measure of the PCS. Trends in PCS overtime can potentially indicate the crack threat susceptibility the integrity assessment interval should be updated. Two examples observed on pipeline segments within Enbridge pipeline system are provided that show the PCS change over time. Conclusions are drawn for the PCM program thereafter.

Effect of Pressure Loading on Integrity Management

2008 ◽  
Author(s):  
Sanjay Tiku ◽  
Aaron Dinovitzer ◽  
Scott Ironside
Keyword(s):  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Operating Pressure ◽  
Integrity Assessment ◽  
Pipeline Segment ◽  
Pressure Cycle ◽  
Integrity Management ◽  
Pump Compressor ◽  
Life Predictions

Integrity assessment or life predictions for in-service pipelines are sensitive to the assumptions they rely upon. One significant source of uncertainty is the pipeline operating pressure data often captured and archived using a Supervisory Control and Data Acquisition (SCADA) system. SCADA systems may be programmed to collect and archive data differently from one pipeline to another and the resulting pressure records can be significantly different on the basis of the sampling techniques, data processing and the distance from pump and compressor stations. This paper illustrates some of the issues involved in pressure load characterization and is based upon work sponsored by the Pipeline Research Council International (PRCI). A series of sensitivity studies using fatigue crack growth calculations have been carried out to evaluate several factors that can influence crack stability and growth predictions that are often employed in pipeline integrity planning and repair programs. The results presented will highlight the issues related to performing integrity management based upon pump/compressor discharge or suction SCADA data to characterize the potential severity of pressure fluctuation or peak pressure dependent defects, illustrate the differences in fatigue crack growth rates along a pipeline segment and demonstrate the complexity of pressure cycle severity characterization, based upon distance from discharge, elevation, hydraulic gradient, for different sites along the pipeline route.

Use of Risk and Engineering Assessments to Improve Safety in Class Location Changes: South American Case Study

2018 ◽  
Author(s):  
John Erick Malpartida Moya
Keyword(s):  
South America ◽  
Wall Thickness ◽  
Primary Objective ◽  
Third Party ◽  
Lower Probability ◽  
South American ◽  
Operating Pressure ◽  
Design Code ◽  
Integrity Management

In South America, there is not a unique standard that regulates the Design, Operation, Maintenance and Integrity Management of Pipelines. Most of the countries had developed their own regulations and standards based mainly on the ASME Standards. These standards (like ASME B31.8 and ASME B31.8S) are being developed and updated considering the experience of different operators, but the results not always consider the difficulties in terms of social and cultural aspects of construct and operate pipelines in South America. Expansion of existing residential and commercial areas, or the construction of new developments near these pipelines can change a Location Class 1 into a Class 2 or Class 3 location. This development is not always predictable, besides the efforts of the South American Pipelines Operators made to coordinate this expansions with the local authorities, the growth in these countries are not well planned and the Operators are forced to face the situation without anticipation and without a backup of the regulations. Then the operators are unexpectedly left with a pipeline that no longer meets the requirements of its design code. ASME B31.8 establishes alternatives to adequate this changes into the design code: reducing the maximum allowable operating pressure of a pipeline, pipeline replacement increasing the wall thickness or by re-routing it away from the population. Those alternatives have high costs and significant operational difficulties, especially when the social conditions are not favorable. Additionally, some of these options do not even effectively solve the problem. Lowering operating stress levels do not always address the higher risk levels or safety concerns caused by the change in class. Increasing wall thickness, can lower probability of failure for a pipeline but not for all the combinations of threats, which depend on site specific conditions. The Pipeline Integrity Management System shall address all the threats as it is specified in ASME B31.8S, ensuring human safety as its primary objective. Third Party Damage is an important threat which in most of the pipelines around the world has caused the larger number of incidents. To manage this threat, risk assessments have been employed successfully to determine risk based on land use zones, proximity to utilities, alignment markers, one call and dig notification, surveillance intervals, among other variables. Calculating the risk to a specific pipeline near to a population after the mitigation activities are implemented, it may be shown that this pipeline has no more risk than other pipelines operating entirely in accordance with the design codes. Risks must be maintained “as low as reasonably practicable”, using cost benefit analysis to achieve these criteria. The reduction of the risk is accomplished by implementing additional mitigation plans, allowing to effectively use maintenance resources in areas where they will have the highest impact on risk. This paper shows how risk and engineering assessments and their consequent mitigation plans may be used to justify the safe operation of a pipeline without changing its original operating pressure following a change of class designation, exemplified with a case study from South America.

Full Scale Cyclic Fatigue Testing of Dented Pipelines and Development of a Validated Dented Pipe Finite Element Model

2010 ◽  
Author(s):  
Brock Bolton ◽  
Vlado Semiga ◽  
Sanjay Tiku ◽  
Aaron Dinovitzer ◽  
Joe Zhou
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Fatigue Testing ◽  
Complex Function ◽  
Element Model ◽  
Full Scale ◽  
Assessment Model ◽  
Experimental Program ◽  
Integrity Assessment ◽  
Operational Life

Dents in buried pipelines can occur due to a number of potential causes; the pipe resting on rock, third party machinery strike, rock strikes during backfilling, amongst others. The long-term integrity of a dented pipeline segment is a complex function of a variety of parameters, including pipe geometry, indenter shape, dent depth, indenter support, pressure history at and following indentation. In order to estimate the safe remaining operational life of a dented pipeline, all of these factors must be accounted for in the analysis. The goal of the full scale experimental program described in this paper is to compile a database of full scale dent test results that encompasses many of the dent types seen in the field, including plain dents, dents interacting with girth and long seam welds, and dents interacting with metal loss features, in both the unrestrained and restrained condition. The dents are pressure cycled until a fatigue failure occurs in the dent. Typical data recorded includes indentation load/displacement curves, applied pressures, pipe wall OD strains along the axial and circumferential centerlines, and axial and circumferential dent profiles. The full scale tests are being performed on behalf of PRCI and US DoT. This paper is intended to show the matrix of dents considered to date and present a representative summary of the data recorded. In addition to presenting the full scale test program and resulting data, this paper summarizes ongoing efforts to develop a validated pipeline dent integrity assessment model. The model under development makes use of the aforementioned full scale experimental data, to validate a finite element model of the denting and re-rounding process for a variety of dent scenarios (i.e. depths, restraints, indenter sizes). The paper discusses the efforts under way to develop and validate the finite element model with the goal being to estimate the fatigue life. The paper is an extension of work discussed in a previously presented IPC paper [1].

Towards a Validated Pipeline Dent Integrity Assessment Model

2008 ◽  
Author(s):  
Brock Bolton ◽  
Vlado Semiga ◽  
Aaron Dinovitzer ◽  
Sanjay Tiku ◽  
Chris Alexander
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Complex Function ◽  
Time History ◽  
Element Model ◽  
Assessment Model ◽  
Third Party ◽  
Assessment Procedure ◽  
Integrity Assessment ◽  
Operational Life

Detectable dents in buried pipelines can occur due to a number of potential causes; the pipe resting on rock, third party machinery strike, rock strikes during backfilling. The integrity of a dented pipeline segment is a complex function of a variety of parameters, including pipe geometry, indenter shape, dent depth, indenter support and pressure history at and following indentation. In order to estimate the safe remaining operational life of a dented pipeline, all of these factors must be accounted for in the analysis. The following paper summarizes ongoing efforts to develop a validated pipeline dent integrity assessment model. The model under development makes use of experimental tests to validate a finite element model of the denting and re-rounding process for a variety of dent scenarios (i.e. depths, restraints, indenter sizes). The results of the finite element model are then used in conjunction with the estimated pressure-time history in an integrity assessment procedure to estimate the safe remaining operational life of the pipe segment. The paper presents a discussion of the full scale fatigue tests carried out on dented pipeline segments and the efforts under way to develop and validate a finite element model of the experimental specimens with the goal of estimating the experimental fatigue life.

scholarly journals The Principle of Directive-Compliant Development of the Law and the Contra Legem Limit

2020 ◽  
Vol 16 (4) ◽  
pp. 465-488
Author(s):  
Thomas M.J. Möllers
Keyword(s):  
Case Law ◽  
Third Party ◽  
Broad Term ◽  
Legal Texts ◽  
Classical Methodology ◽  
The Law ◽  
Legal Methodology ◽  
The Relationship ◽  
Further Development ◽  
Domestic Law

AbstractThe Europeanisation of domestic law calls for a classical methodology to ‘update’ the established traditions of the law. The relationship between European directives and national law is difficult, since directives do apply, but European legal texts need to be implemented into national law. Whilst directives are not binding on private individuals, there is no direct third-party effect, but only an ‘indirect effect’. This effect is influenced by the stipulations of the ECJ, but is ultimately determined in accordance with methodical principles of national law. The ECJ uses a broad term of interpretation of the law. In contrast, in German and Austrian legal methodology the wording of a provision defines the dividing line between interpretation and further development of the law. The article reveals how legal scholars and the case-law have gradually shown in recent decades a greater willingness to shift from a narrow, traditional boundary of permissible development of the law to a modern line of case-law regarding the boundary of directive-compliant, permissible development of the law.

scholarly journals Fatigue Testing of Wearable Sensing Technologies: Issues and Opportunities

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4070
Author(s):  
Andrea Karen Persons ◽  
John E. Ball ◽  
Charles Freeman ◽  
David M. Macias ◽  
Chartrisa LaShan Simpson ◽  
...  
Keyword(s):  
Fatigue Life ◽  
Prediction Models ◽  
Fatigue Testing ◽  
Low Cycle Fatigue ◽  
Wearable Sensors ◽  
Fatigue Tests ◽  
Proof Of Concept ◽  
Cycle Fatigue ◽  
Wearable Sensing ◽  
Failure Data

Standards for the fatigue testing of wearable sensing technologies are lacking. The majority of published fatigue tests for wearable sensors are performed on proof-of-concept stretch sensors fabricated from a variety of materials. Due to their flexibility and stretchability, polymers are often used in the fabrication of wearable sensors. Other materials, including textiles, carbon nanotubes, graphene, and conductive metals or inks, may be used in conjunction with polymers to fabricate wearable sensors. Depending on the combination of the materials used, the fatigue behaviors of wearable sensors can vary. Additionally, fatigue testing methodologies for the sensors also vary, with most tests focusing only on the low-cycle fatigue (LCF) regime, and few sensors are cycled until failure or runout are achieved. Fatigue life predictions of wearable sensors are also lacking. These issues make direct comparisons of wearable sensors difficult. To facilitate direct comparisons of wearable sensors and to move proof-of-concept sensors from “bench to bedside,” fatigue testing standards should be established. Further, both high-cycle fatigue (HCF) and failure data are needed to determine the appropriateness in the use, modification, development, and validation of fatigue life prediction models and to further the understanding of how cracks initiate and propagate in wearable sensing technologies.

Pipeline Corrosion Integrity Management by Direct Assessment

2015 ◽  
Author(s):  
Shailesh Javia
Keyword(s):  
Integrated Approach ◽  
Assessment Process ◽  
Regulatory Requirements ◽  
Integrity Assessment ◽  
Advantages And Disadvantages ◽  
Direct Assessment ◽  
Pipeline Segment ◽  
Integrity Management ◽  
Post Assessment ◽  
Pipeline Corrosion

Integrity management of pipelines is a systematic, comprehensive and integrated approach to proactively counter the threats to pipeline integrity. Pressure testing, in-line inspection and direct assessment methods are used to verify the integrity of a buried pipeline. The Paper Discuses Direct Assessment Methodologies for Hydrocarbon Non Piggable Pipelines. Advantages and Disadvantages of Direct Assessment methodology and DA Protocols. The DA process accomplishes this by utilizing and integrating condition monitoring, effective mitigation, meticulous documentation and timely structured reporting processes. DA is a structured, iterative integrity assessment process through which an operator may be able to assess and evaluate the integrity of a pipeline segment. TIME DEPENDENT THREATS INEVITABLY LED TO NUMEROUS FAILURES WITH A COMMON DEFINING MECHANISM OR SOURCE – CORROSION. This Paper will focus on internal, external and stress corrosion cracking direct assessment along with pre and post assessment, quality assurance, data analysis and integration, and remediation and mitigation activities. This paper will discuss some of the regulatory requirements for Pipeline Integrity Management System.

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