scholarly journals Use of Phased Array Ultrasonic Testing For Sizing of Hydrogen Blisters In LPG Wash Water Vessel In INDMAX Unit

2012 ◽  
pp. 203-207
Author(s):  
Mayank Banjare ◽  
Mahendra Pal Pal ◽  
Ch. Nanacharaiah ◽  
V. S. Desai ◽  
Sushil Guria ◽  
...  
Keyword(s):  
Ultrasonic Testing ◽  
Hydrogen Molecule ◽  
Phased Array ◽  
Damage Mechanism ◽  
Wash Water ◽  
Fitness For Purpose ◽  
Hydrogen Atoms ◽  
Safe Operation ◽  
In Series ◽  
Hydrogen Blister

Equipments operating in sour environment containing H2S are prone to deterioration by wet H2S damage mechanism. INDMAX unit (patented FCCU) produces LPG which contains H2S, cyanide as impurities. To remove these impurities LPG is treated with caustic wash and subsequently water wash in series operation. Due to presence of wet H2S environment in the water wash vessel, nascent hydrogen is produced which diffuses in to the wall of the vessel. Due to presence of laminations in the CS shell these hydrogen atoms combined to form hydrogen molecule which exerts severe internal pressure greater than the yield strength of the CS wall inside the laminations resulting in formation of hydrogen blister. This paper describes the use of phased array UT (PAUT) technique for detection of lamination and sizing of hydrogen blisters in the LPG wash water vessel. Fitness for purpose study was carried out for safe operation of this vessel.

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.

Ultrasound and Nonlinear Resonant Testing of Nuclear Reactor Internals Bolts

2011 ◽  
Author(s):  
S. W. Glass ◽  
B. Thigpen ◽  
J. Renshaw
Keyword(s):  
Phased Array ◽  
Nuclear Reactor ◽  
Structural Integrity ◽  
Cost Effective ◽  
Life Extension ◽  
Safe Operation ◽  
Plant Life ◽  
Nuclear Plants ◽  
Bolt Failure ◽  
Reactor Internals

As many nuclear plants approach the end of their initial 40 year license period, inspection or replacement of their reactor internals bolts must be considered. This is consistent with the Materials Reliability Program (MRP 227/228) guideline for plant life extension [1,2]. Assurance of the internals structural integrity is essential for continued safe operation of these plants. If there is no suspicion or indication of bolt failure, simple inspection is normally more cost-effective than replacement. Inspection vendors have inspected thousands of internals bolts with conventional and Phased Array UT but different head configurations and bolt capture mechanisms mandate specific qualifications for each bolt type. In some cases, complex bolt and head geometries coupled with counter-bore and locking bar interferences render classical UT inspections difficult or impossible. A range of solutions to inspect reactor internals including these difficult-to-inspect-by-conventional-UT baffle bolts has been developed by several vendors [3]. This presentation references developments to make bolt inspection a relatively quick and easy task through adaptations to the SUSI submarine inspection platform, the extensive UT qualification work suitable for conventional UT plus more recent advanced nonlinear resonant techniques to distinguish between flawed or loose, vs. acceptable bolts where conventional UT cannot be applied. Initial evaluations show that these advanced techniques may have the ability to reliably detect smaller flaws than previously possible with conventional techniques as well as provide information on bolt tightness.

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.

scholarly journals Relationship between the Behavior of Hydrogen and Hydrogen Bubble Nucleation in Vanadium

Materials ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 322
Author(s):  
Zhengxiong Su ◽  
Sheng Wang ◽  
Chenyang Lu ◽  
Qing Peng
Keyword(s):  
Hydrogen Atom ◽  
First Principles ◽  
Bound States ◽  
Hydrogen Molecule ◽  
Vacancy Cluster ◽  
Bubble Nucleation ◽  
Hydrogen Bubble ◽  
First Principles Calculations ◽  
Hydrogen Atoms ◽  
Macroscopic Deformation

Hydrogen plays a significant role in the microstructure evolution and macroscopic deformation of materials, causing swelling and surface blistering to reduce service life. In the present work, the atomistic mechanisms of hydrogen bubble nucleation in vanadium were studied by first-principles calculations. The interstitial hydrogen atoms cannot form significant bound states with other hydrogen atoms in bulk vanadium, which explains the absence of hydrogen self-clustering from the experiments. To find the possible origin of hydrogen bubble in vanadium, we explored the minimum sizes of a vacancy cluster in vanadium for the formation of hydrogen molecule. We show that a freestanding hydrogen molecule can form and remain relatively stable in the center of a 54-hydrogen atom saturated 27-vacancy cluster.

Safe Operation of DFIG based Wind Parks in Series Compensated Systems

2018 ◽  
Author(s):  
Ulas Karaagac ◽  
Jean Mahseredjian ◽  
Simon Jensen ◽  
Richard Gagnon ◽  
Martin Fecteau ◽  
...  
Keyword(s):  
Safe Operation ◽  
In Series

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.

Sign in / Sign up

Export Citation Format

Share Document