A Combined Approach to Characterization of Dent With Metal Loss

Author(s):  
Rick Yahua Wang ◽  
Richard Kania ◽  
Udayasankar Arumugam ◽  
Ming Gao

Current in-line inspection technologies (e.g., Caliper/MFL or Combo) for mechanical damage characterization can detect dent with metal loss but with limited ability to discriminate metal loss between corrosion, gouge and crack with certainty. There are also some cases that metal loss signals were detected but not reported by ILI vendors because of either signals below threshold for reporting or other reasons. Practical experience showed that, with assistance of strain based dent analysis and strain limit damage criteria; detailed characterization of MFL tri-axial signals could effectively facilitate to discriminate metal loss features and identify potential risk of cracks or gouges in the dent. In this paper, the newly developed approach is utilized to identify the critical dents in the pipelines and discriminate those dents associated with metal loss reported by combined ILI technologies. A case study was performed with four real dent features, as an example to demonstrate the effectiveness of this approach. The details of the case study, results and findings are summarized in this paper.

2005 ◽  
Vol 127 (3) ◽  
pp. 274-283 ◽  
Author(s):  
J. Bruce Nestleroth ◽  
Richard J. Davis

This paper describes the design of a new magnetic flux leakage (MFL) inspection tool that performs an inline inspection to detect and characterize both metal loss and mechanical damage defects. An inspection tool that couples mechanical damage assessment as part of a routine corrosion inspection is expected to have considerably better prospects for application in the pipeline industry than a tool that complicates existing procedures. The design is based on study results that show it is feasible to detect and assess mechanical damage by applying a low magnetic field level in addition to the high magnetic field employed by most inspection tools. Nearly all commercially available MFL tools use high magnetic fields to detect and size metal loss such as corrosion. A lower field than is commonly applied for detecting metal loss is appropriate for detecting mechanical damage, such as the metallurgical changes caused by impacts from excavation equipment. The lower field is needed to counter the saturation effect of the high magnetic field, which masks and diminishes important components of the signal associated with mechanical damage. Finite element modeling was used in the design effort and the results have shown that a single magnetizer with three poles is the most effective design. Furthermore, it was found that for the three-pole system the high magnetization pole must be in the center, which was an unexpected result. The three-pole design has mechanical advantages, including a magnetic null in the backing bar, which enables installation of a pivot point for articulation of the tool through bends and restrictions. This design was prototyped and tested at Battelle’s Pipeline Simulation Facility (West Jefferson, OH). The signals were nearly identical to results acquired with a single magnetizer reconfigured between tests to attain the appropriate high and low field levels.


Materials ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 995 ◽  
Author(s):  
Razvan Udroiu ◽  
Ion Braga ◽  
Anisor Nedelcu

The performance characterization of the manufacturing processes for additive manufacturing (AM) systems is a significant task for their standardization and implementation in the industry. Also, there is a large diversity of materials used in different AM processes. In the present paper, a methodology is proposed to evaluate, in different directions, the performance of an AM process and material characterization in terms of surface quality. This methodology consists of eight steps, based on a new surface inspection artifact and basic artifact orientations. The proposed artifact with several design configurations fits different AM systems sizes and meets the needs of customers. The effects of main factors on the surface roughness of up-facing platens of the artifacts are investigated using the statistical design of experiments. The proposed methodology is validated by a case study focused on PolyJet material jetting technology. Samples are manufactured of photopolymer resins and post-processed. Three factors (i.e., artifact orientation, platen orientation, and finish type) are considered for the investigation. The case study results show that the platen orientation, finish type, and their interaction have a significant influence on the surface roughness (Ra). The best Ra roughness results were obtained for the glossy finish type in the range of 0.5–4 μm.


Author(s):  
Vanessa Co ◽  
Scott Ironside ◽  
Chuck Ellis ◽  
Garrett Wilkie

Management of mechanical damage is an issue that many pipeline operators are facing. This paper presents a method to characterize dents based on the analysis of the BJ Vectra Magnetic Flux Leakage (MFL) tool signals. This is an approach that predicts the severity of mechanical damage by identifying the presence of some key elements such as gouging, cracking, and metal loss within dents as well as multiple dents and wrinkles. Enbridge Pipelines Inc. worked with BJ Services to enhance the knowledge that can be gained from MFL tool signals by defining tool signal subtleties in dents. This additional characterization provides information about the existence of gouging, metal loss, and cracking. This has been accomplished through detailed studies of the ILI data and follow-up field investigations, which validate the predictions. One of the key learnings has been that the radial and circumferential components of the MFL Vectra tool are highly important in the characterization and classification of mechanical damage. Non-destructive examination has verified that predictions in detecting the presence of gouging and cracking (and other defects within dents based on tool signals) have been accurate.


Author(s):  
Luis A. Torres ◽  
Matthew J. Fowler ◽  
Jordan G. Stenerson

Integrity management of dents on pipelines is currently performed through the interpretation of In-Line Inspection (ILI) data; this includes Caliper, Magnetic Flux Leakage (MFL), and Ultrasonic Testing (UT) tools. Based on the available ILI data, dent features that are recognized as threats from a mechanical damage perspective are excavated and remediated. Federal codes and regulations provide rules and allow inference on what types of dent features may be a result of mechanical damage; nonetheless, there are challenges associated with identifying dents resulting from mechanical damage. One of the difficulties when managing the mechanical damage threat is the lack of information on how MFL and UT ILI tool performance is affected by dented areas in the pipe. ILI vendors do not offer any technical specifications for characterizing and sizing metal loss features in dents. It is generally expected that metal loss tool performance will be affected in dented areas of the pipe, but it is not known to what degree. It is likely that degradation will vary based on feature shape, sensor design, and sensor placement. Because metal loss tool performance is unknown within the limits of the dented pipe, other methods for recognizing mechanical damage have been incorporated into the management strategies of mechanical damage. Some of these methods include strain based assessments and characterization of shape complexity. In order to build a more effective integrity management program for mechanical damage, it is of critical importance to understand how tool technology performance is affected by dented areas in the pipe and what steps can be taken to use ILI information more effectively. In this paper, the effectiveness of MFL and UT wall measurement tools in characterizing and sizing metal loss features within dents is studied by evaluating against field results from non-destructive examinations of mechanical damage indications. In addition, the effectiveness of using shape complexity indicators to identify mechanical damage is evaluated, introducing concepts such as dents in close proximity and multi-apex dents. Finally, the effectiveness of ILI tools in predicting dent association with girth welds is also explored by comparing ILI and field results.


2019 ◽  
Vol 48 (2) ◽  
pp. 3-12
Author(s):  
Dimitar Antonov ◽  
Nikolay Stoyanov ◽  
Aleksey Benderev

The Repository for Radioactive Waste in Novi Han, Lozen Mountain (Bulgaria), dates from the early 1960s. In the present study, the complex geoenvironmental setting of the repository site was analysed from the viewpoint of assessment of potential radionuclide migration from the repository to the geosphere. Thus, components of the mass transport field were elaborated as a part of a conceptual model. In connection with this, a detailed characterization of the subsurface, especially of the vadose zone around the repository, was performed. The fractions of sand, silt and clay based on the grain-size distribution curves of samples from the different hydrogeological units gathered on the site of RAW-Novi Han were implemented in the ROSETTA program, and the respective hydraulic parameters were determined. As a result, the entire vadose zone was hydraulically determined.


Author(s):  
Udayasankar Arumugam ◽  
Ming Gao ◽  
Ravi Krishnamurthy ◽  
Rick Wang ◽  
Richard Kania

A combined caliper and tri-axial MFL in-line inspection (ILI) reported a bottom side 2.7%OD dent associated with 76% metal loss. The reported dent depth is well below the 6% limit while strain analysis of this ILI dent profile showed a maximum equivalent strain of 17.4%, which exceeds the 6% strain limit for gas pipeline. Due to the high dent strain level, the raw signals of metal loss were revisited, which indicated this associated metal loss appears to be a crack rather than corrosion. In-field investigation revealed that this dent is indeed associated with branched cracks both at internal and external pipe surface but no leak was detected. The primary objective of this case study is to determine the cause for cracking in the dent. As part of this study, detailed investigation was performed including LaserScan based strain analysis, lab pressure-cycle testing and fracture surface examination. An attempt was made to quantify the plastic strain damage of this dent and its susceptibility to cracking using the existing plastic damage models, namely, ductile failure damage indicator (DFDI), strain limit damage (SLD) and minimum elongation limit criterion. The investigation showed that the internal cracks were formed at the time of indentation while the external cracks formed by spring-back (elastic rebounding) due to the removal of rock constraint. Full size fatigue testing of this cracked dent showed leak failure modes rather than rupture. In this paper, the approach, results and the findings are summarized and discussed.


Author(s):  
Fabian Hunke ◽  
Daniel Heinz ◽  
Gerhard Satzger

AbstractThe digital transformation offers new opportunities for organizations to expand their existing service portfolio in order to achieve competitive advantages. A popular way to create new customer value is the offer of analytics-based services (ABS)—services that apply analytical methods to data to empower customers to make better decisions and to solve complex problems. However, research still lacks to provide a profound conceptualization of this novel service type. Similarly, actionable insights on how to purposefully establish ABS in the market to enrich the service portfolio remain scarce. We perform a cluster analysis of 105 ABS and triangulate it with a revelatory case study to identify four generic ABS archetypes and to unveil their specific service objectives and characteristics. We also isolate essential factors that shape decision-making regarding the choice of adequate archetypes and subsequent transitions between them. The detailed characterization of different ABS types contributes to a more profound theorizing process on ABS as well as provides a systematization for strategic opportunities to enrich service portfolios in practice.


Author(s):  
D. L. Callahan

Modern polishing, precision machining and microindentation techniques allow the processing and mechanical characterization of ceramics at nanometric scales and within entirely plastic deformation regimes. The mechanical response of most ceramics to such highly constrained contact is not predictable from macroscopic properties and the microstructural deformation patterns have proven difficult to characterize by the application of any individual technique. In this study, TEM techniques of contrast analysis and CBED are combined with stereographic analysis to construct a three-dimensional microstructure deformation map of the surface of a perfectly plastic microindentation on macroscopically brittle aluminum nitride.The bright field image in Figure 1 shows a lg Vickers microindentation contained within a single AlN grain far from any boundaries. High densities of dislocations are evident, particularly near facet edges but are not individually resolvable. The prominent bend contours also indicate the severity of plastic deformation. Figure 2 is a selected area diffraction pattern covering the entire indentation area.


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