Characterization of Mechanical Damage Through Use of the Tri-Axial Magnetic Flux Leakage Technology

2006 ◽  
Author(s):  
Vanessa Co ◽  
Scott Ironside ◽  
Chuck Ellis ◽  
Garrett Wilkie
Keyword(s):  
Magnetic Flux ◽  
Mechanical Damage ◽  
Magnetic Flux Leakage ◽  
Metal Loss ◽  
Field Investigations ◽  
Non Destructive ◽  
Flux Leakage

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.

The Design of a Mechanical Damage Inspection Tool Using Dual Field Magnetic Flux Leakage Technology

2005 ◽  
Vol 127 (3) ◽  
pp. 274-283 ◽  
Author(s):  
J. Bruce Nestleroth ◽  
Richard J. Davis
Keyword(s):  
Magnetic Field ◽  
Magnetic Flux ◽  
High Magnetic Field ◽  
Mechanical Damage ◽  
Magnetic Flux Leakage ◽  
Metal Loss ◽  
Unexpected Result ◽  
Lower Field ◽  
Study Results ◽  
Flux Leakage

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.

API 579 Level 3 Assessment of Dents Using High-Resolution ILI Data

2011 ◽  
Author(s):  
Chas Jandu ◽  
Mike Taylor ◽  
Suji Narikotte
Keyword(s):  
High Resolution ◽  
Magnetic Flux ◽  
Single Channel ◽  
Mechanical Damage ◽  
Magnetic Flux Leakage ◽  
Metal Loss ◽  
Operating Pressure ◽  
Data Set ◽  
Level 3 ◽  
Flux Leakage

In-line Inspection (ILI) surveys are periodically performed to determine the condition of the pipeline. Typical ILI surveys involve Magnetic Flux Leakage primarily to determine metal loss and simple single channel Calliper surveys to determine any signs of geometry imperfections. Additional surveys such as high-resolution multi-channel Calliper deformation tools are occasionally used to accurately record imperfections to enable a more accurate assessment of the integrity of the pipeline containing the imperfection. Such tools have had limited employment, and therefore little experience exists of using the data obtainable for the detailed assessment of defects. This paper presents a study of such a case. As part of an In-line Inspection (ILI) of an offshore pipeline, a high-resolution deformation survey recorded numerous dent anomalies which had potentially resulted from a single dragged anchor incident before the pipeline was trenched. This data set was correlated to Magnetic Flux Leakage inspection data to confirm external mechanical damage. Pipeline sections having anomalies that were either found close to girth welds, or had associated corrosion defects were automatically selected for repair. The remaining anomalies were assessed in order to determine their acceptability for the maximum allowable operating pressure using the approaches detailed in API-579. Due to the sharp nature of some of the dents, elastic-plastic finite element analyses (FEA) were performed using denting profiles generated from the calliper data of the ILI run. API-579 level 3 assessments were then carried out using the FEA results. This paper details the high-resolution deformation tool findings and the approach used in order to assess the fitness-for-purpose of the pipe with the recorded anomalies.

scholarly journals Characterization of Defect for Magnetic Flux Leakage in Non-Destructive Test using I-Kaztm

2020 ◽  
Vol 8 (5) ◽  
pp. 881-886
Keyword(s):  
Magnetic Flux ◽  
Magnetic Flux Leakage ◽  
Monitoring Methods ◽  
Signal Distribution ◽  
Scanning Device ◽  
Hall Sensors ◽  
Non Destructive ◽  
Derivatives Of ◽  
Flux Leakage

The application of hall sensors in Magnetitic Flux Leakage (MFL) has played an important role in Above Storage Tank (AST) on detection of defect caused by corrosion to improve productivity and to avoid catastrophe. The MFL sensor measured magnetic flux distribution in three axes Bx , By and Bz. Currently, there are several signal monitoring methods constructed by analysing MFL signal distribution upon defect detection. This paper presents the methodology of optimized Integrated Kurtosis-based Algorithm for Z-filter (I-KazTM) Coefficient using multilevel signal decomposition technique to analyse the MFL signal distribution on the defect in the correlation of MFL scanning device speed and position. The MFL scanning device comprises 11 hall effect sensors position in array coupled with a linear guide to ensuring a constant velocity of scanning. In order to obtain an optimum signal distribution, I-KazTM 3D is proposed as one of the derivatives of I-KazTM to analyse multiple velocities of scanning. The characterization of the defect can be estimated by analysing the deflection of magnetic flux leakage in the y-axis, By as the scanner approach the defect region before being analysed by I-KazTM from the beginning until the end of the workpiece.

Characterization of Defects on Ferromagnetic Tubes Using Magnetic Flux Leakage

2019 ◽  
Vol 55 (5) ◽  
pp. 1-10 ◽  
Author(s):  
V. Suresh ◽  
A. Abudhahir ◽  
Jackson Daniel
Keyword(s):  
Magnetic Flux ◽  
Magnetic Flux Leakage ◽  
Flux Leakage

Geometric Magnetic and Discriminator Sensor for Smart Pigs

2004 ◽  
Author(s):  
Vinicius de C. Lima ◽  
Jose´ A. P. da Silva ◽  
Jean Pierre von der Weid ◽  
Claudio Soligo Camerini ◽  
Carlos H. F. de Oliveira
Keyword(s):  
High Resolution ◽  
Magnetic Flux ◽  
Magnetic Flux Leakage ◽  
Metal Loss ◽  
Research Partnership ◽  
Technical Aspects ◽  
Pipeline Inspection ◽  
Catholic University ◽  
Laboratory Results ◽  
Flux Leakage

A result of a research partnership between Catholic University of Rio de Janeiro – PUC-Rio, PETROBRAS and PIPEWAY is presented: The development of an innovative sensor head for high resolution MFL Pigs, the GMD sensor, Geometric Magnetic and Discriminator. This head makes high resolution magnetic pipeline readings using the MFL - Magnetic Flux Leakage technique, with the addition of geometric readings and the outside/inside defects discriminations. This technique makes possible, with only one crown of GMD sensors, the caliper, metal loss and outside/inside discrimination pipeline inspection. Technical aspects of the development, e.g.: the construction details of the sensor, evaluation tests and laboratory results are also presented.

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