Advanced Ultrasonic Techniques in Pipeline Girth Welds Examination

2003 ◽  
Author(s):  
Giuseppina Cataldo ◽  
Roberto Legori
Keyword(s):  
Standard Method ◽  
Ultrasonic Testing ◽  
Phased Array ◽  
Critical Assessment ◽  
Radiation Hazard ◽  
Inspection System ◽  
Chemical Waste ◽  
Philosophy Of Engineering ◽  
Ultrasonic Techniques ◽  
Girth Welds

Installation of pipelines onboard a lay-barge requires rapid inspection and judgement of all girth welds prior to leaving the vessel. Furthermore, the new philosophy of Engineering Critical Assessment (ECA) based on the principles of fracture mechanics to assess the severity of a defect on its vertical extent requires the application of an inspection system able to accurately assess height, length and through thickness location of the defect in order to reducing the number of unnecessary repairs. Automated Ultrasonic Testing (AUT) is rapidly replacing radiography as standard method of inspecting pipeline girth welds, reducing pipeline costs through increased productivity and avoiding the radiation hazard and the chemical waste of the film processing. This paper describes SAIPEM experience with the new Phased Array AUT technology carried out on several projects, particularly with reference to the ultra-deep water Blue Stream Project, which required an extensive qualification of the AUT System in accordance to DNV Rules [1,2].

TOFD Automatic Ultrasonic Testing for Condition Monitoring of Coke Drums

2003 ◽  
Author(s):  
Jorge A. Penso ◽  
Robert Owen ◽  
Masaaki Oka
Keyword(s):  
Condition Monitoring ◽  
Ultrasonic Testing ◽  
Phased Array ◽  
Service Evaluation ◽  
Pressure Vessels ◽  
Inspection System ◽  
Delayed Coking ◽  
Advantages And Disadvantages ◽  
Mechanical Cycling ◽  
History Of

Cracking and bulging in welded and internally lined pressure vessels that work in thermal-mechanical cycling service have been well known problems in the petrochemical, power and nuclear industries. In spite of this problem has been studied during the last fifty years, published literature and industry surveys show that similar problems still occur nowadays. Typical examples of this problem are the coke drums in the delayed coking units refinery process. Delayed coking units are among the refinery units that have higher economical yields. To shut down these units represents a high negative economical impact in refinery operations. Also, the maintenance costs associated with repairs are commonly very high. Cracking and bulging occurrences in the coke drums, most often at the weld areas, characterize the history of the operation of delayed coking units. To anticipate through wall cracking in these coke drums, AUT (automatic ultrasonic testing); Dual TOFD (time of flight diffraction) and the Phased Array technique simultaneous inspection system was selected among other inspection techniques as a condition monitoring tool during an unit turnaround. The inspection methodology in combination with fracture mechanics was used to classify discontinuities as acceptable and non-acceptable. This indicated approach helped to optimize the workscope during the turnaround and establish guidelines for inspection and repair of the delayed coker unit. This work presents the different steps followed during the inspection and fitness for service evaluation. Also, this study shows advantages and disadvantages of the AUT-Phased Array technique.

Development of Ultrasonic Phased Array Probe for SAW Seam Inspection of UOE Pipe

2007 ◽  
Author(s):  
Masaki Yamano ◽  
Hiroyuki Okubo ◽  
Takumi Horikiri ◽  
Makoto Nagase
Keyword(s):  
Phased Array ◽  
Inspection System ◽  
Line Pipe ◽  
Array Probe ◽  
Ultrasonic Phased Array ◽  
Detection Capabilities ◽  
Girth Welds ◽  
Welded Seam ◽  
Submerged Arc ◽  
Pipe Mill

The requirements of Ultrasonic Testing, such as DNV, ISO specification etc., for longitudinal submerged arc weld (SAW) seam of UOE pipe become severe to the offshore steel line-pipe with high grade and heavy wall thickness. In order to satisfy the requirements, testing method with multi-probe arrangement have been widely applied in the pipe manufacture. Recently, the phased array technique has been applied for inspection of girth welds of pipeline and longitudinal ERW (electric resistance welded) seam instead of multi-probe method. But the inspection system with conventional phased array probe has many difficulty to apply for inspection longitudinal SAW seam of UOE pipe, because of defect detection capabilities, array elements arrangement, and so on. The authors have developed an applicable ultrasonic phased array probe to satisfy the severe requirements for longitudinal SAW seam of UOE pipe. This paper presents the results of our original designed array probe, which has been composed of 32-transducer elements mounted on cylindrical-shaped plastics, and also compares the inspection results to those obtained on the conventional multi-probe and our developed array probe in the UOE pipe mill.

An Automatic Flaw Identification Method for Defect Inspection of Pipeline Girth Weld

2008 ◽  
Author(s):  
Jian Li ◽  
Xianglin Zhan ◽  
Shili Chen ◽  
Jingchang Zhuge ◽  
Shijiu Jin ◽  
...  
Keyword(s):  
Phased Array ◽  
Flaw Detection ◽  
Inspection System ◽  
Energy Status ◽  
Long Distance ◽  
Feature Extraction Method ◽  
Identification Method ◽  
Ultrasonic Phased Array ◽  
Flaw Classification ◽  
Girth Welds

Various types of defect may be formed in girth welds of long-distance pipeline in the process of welding. They are hidden dangers to pipeline transportation safety. Currently, ultrasonic phased array instrument is commonly adopted for quick automatic positioning and quantitative analysis of flaws in the girth weld after welding. But as for qualitative analysis – flaw classification, traditional manual identification method is still used. By traditional method, human-made error is easily introduced and classification result is depended on the detection experiences of the inspecting person. To overcome these deficiencies, a new method combined second generation wavelet transform (SGWT) with Radial Basis Function neural network (RBFN) is proposed in this paper, realizing automatic flaw classification and reducing human factors impaction. SGWT is ideally matched local characteristics of the flaw signal, improving both the computational speed and flaw classification efficiency. Then, based on the “energy-status” feature extraction method and the above SGWT analysis, feature eigenvectors of the flaw signals are extracted, training the following RBFN. And then when the feature of any flaw is extracted, it can be recognized by the network. The output of the network is the type of the input flaw signal, realizing automatic flaw classification. Finally, an ultrasonic phased array inspection system is described. The system is integrated with automatic flaw detection and classification. Experiments are tested on a long-distance pipeline girth weld block with artificial defects in it. The results validate that the proposed method is efficient, which is helpful to increasing inspection speed and reliability of flaw inspection for long-distance pipeline girth welds.

Productivity and Reliability Study of Non Destructive Testing Techniques for Inspection of Structural Welds in Construction Industry

NDT World ◽  
2016 ◽  
Vol 19 (3) ◽  
pp. 35-39
Author(s):  
Чан ◽  
Alan Chan ◽  
Бабу ◽  
Sajeesh Kumar Babu ◽  
Чан ◽  
...  
Keyword(s):  
Construction Industry ◽  
Ultrasonic Testing ◽  
Phased Array ◽  
Flaw Detection ◽  
Slag Inclusion ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Ultrasonic Techniques ◽  
Testing Techniques ◽  
Non Destructive

Introduction. The aim of this study is to evaluate the productivity and reliability of non-destructive testing techniques for the inspection of structural welds employed in the Hong Kong construction industry. Method. Manual ultrasonic pulse echo method and semi-automatic ultrasonic techniques using phased array (PAUT) as well as radiographic testing were employed. Five classes of defects were analyzed: lack of penetration, lack of fusion, crack, porosity and slag inclusion. The tests were carried out on the specimen made from structural plate, on which artefacts were inserted on the weld metal. The results were being studied to compare the defect detection reliability by both ultrasonic techniques. The flaw detection productivity using phased array is also compared with conventional ultrasonic testing at a determined rate. Results. The reliability of PAUT was 100% compared to 96.7% with manual ultrasonic testing, however with the inclusion of defect sizing and tolerance the reliability of manual UT is dropped to 57.4%, which implies there is a chance of 42.6% of improper sizing). PAUT exhibits the reliability of 87.5%. The research will be continued with the aim of determining the most appropriate and reliable NDT methods in each case.

scholarly journals Design Considerations for the Use of Ultrasonic Phased Array Probes in Weld Inspection

2000 ◽  
Author(s):  
Paul A. Meyer
Keyword(s):  
Ultrasonic Testing ◽  
Phased Array ◽  
Design Considerations ◽  
Array Probe ◽  
Ultrasonic Phased Array ◽  
Weld Inspection ◽  
Service Inspection

Ultrasonic testing of metal welds has been in use for many years. Scanning methods using both contact and immersion methods are often used at the time of manufacture and also during periodic in-service inspection programs. But because of a variety of component configurations and potential flaw geometries it is often necessary to perform several inspections, each with a different probe configuration to assure adequate defect delegability. It is possible that a properly designed phased array probe can perform several different inspections without changing hardware thereby reducing inspection times. This presentation reviews the design and operation of ultrasonic phased array transducers and the necessary features to achieve the desired performance. Situations in which these probes have already been implemented effectively are also discussed.

Optimizing Probe Active Aperture for Phased Array Weld Inspections

2021 ◽  
Vol 79 (8) ◽  
pp. 797-804
Author(s):  
Anmol Birring
Keyword(s):  
Fracture Mechanics ◽  
Ultrasonic Testing ◽  
Phased Array ◽  
Pressure Vessels ◽  
Acceptance Criteria ◽  
Nondestructive Technique ◽  
Cross Sectional ◽  
Area Of Interest ◽  
Array Technology ◽  
Selection Of

Phased array ultrasonic testing (PAUT) has become a popular nondestructive technique for weld inspections in piping, pressure vessels, and other components such as turbines. This technique can be used both in manual and automated modes. PAUT is more attractive than conventional angle-beam ultrasonic testing (UT), as it sweeps the beam through a range of angles and presents a cross-sectional image of the area of interest. Other displays are also available depending on the software. Unlike traditional A-scan instruments, which require the reconstruction of B- and C-scan images from raster scanning, a phased array image is much simpler to produce from line scans and easier to interpret. Engineering codes have incorporated phased array technology and provide steps for standardization, scanning, and alternate acceptance criteria based on fracture mechanics. The basis of fracture mechanics is accurate defect sizing. There is, however, no guidance in codes and standards on the selection and setup of phased array probes for accurate sizing. Just like conventional probes, phased array probes have a beam spread that depends on the probe’s active aperture and frequency. Smaller phased array probes, when used for thicker sections, result in poor focusing, large beam spread, and poor discontinuity definition. This means low resolution and oversizing. Accurate sizing for fracture mechanics acceptance criteria requires probes with high resolution. In this paper, guidance is provided for the selection of phased array probes and setup parameters to improve resolution, definition, and sizing of discontinuities.

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