Non-destructive examination of fusion welds. Visual examination

1997 ◽  
2014 ◽  
Vol 27 ◽  
pp. 1460135
Author(s):  
CARMEN PAVEL ◽  
FLORIN CONSTANTIN ◽  
COSMIN IOAN SUCIU ◽  
ROXANA BUGOI

X-ray Computed Tomography (CT) is a powerful non-destructive technique that can yield interesting structural information not discernible through visual examination only. This paper presents the results of the CT scans of four objects belonging to the Romanian cultural heritage attributed to the Vinča, Cucuteni and Cruceni-Belegiš cultures. The study was performed with an X-ray tomographic device developed at the Department for Applied Nuclear Physics from Horia Hulubei National Institute for Nuclear Physics and Engineering in Măgurele, Romania. This apparatus was specially designed for archaeometric studies of low-Z artifacts: ceramic, wood, bone. The tomographic investigations revealed the internal configuration of the objects and provided information about the degree to which the previous manipulations affected the archaeological items. Based on the X-ray images resulting from the CT scans, hints about the techniques used in the manufacturing of the artifacts were obtained, as well as some indications useful for conservation/restoration purposes.


2021 ◽  
Author(s):  
Atul Sutar ◽  
Anil Babar

This paper examines many aspects of structural auditing, including visual examination, non-destructive testing, core sample, and testing. It also emphasises various building repairs and retrofitting procedures that should be employed after a structural audit. As the structure matures, it need frequent maintenance and inspection in order to avoid further damage. The health and performance of a building are dependent on its maintenance quality. In order to protect the structure from environmental effects, it should be monitored on a regular basis by a professional. As a result, a structure audit is performed to assess the overall health of the building. A structure audit is a preliminary technical survey performed on a structure to recommend repair solutions.


Author(s):  
Harald Thon ◽  
Bjo̸rn Melve

The document describes practical experience gained from several research programmes and the use of GRP products both offshore and onshore. An OLF document was compiled during 1990’s and the visual inspection part of the document was used in the ISO 14692, part 4 [12] with requirements and defect criteria. Additional parts on ultrasonic and radiographic examination have been included in the Norwegian standard Norsok M-622 [1]. However, we would like to publish the full version of this document and make it available in the public domain. Some of the methods described is well developed, while others still would require research efforts to make the techniques practical useful. For practical use, the visual examination with failure description, acceptance criteria and corrective actions are most developed. Further, radiography has been useful in several projects in assessing the quality of adhesive joints. The ultrasonic testing is expected to become better to use as the equipments and methods are developing. Every reasonable effort has been made to ensure that this publication is based on the author’s best knowledge. However, no responsibility of any kind for any injury, delay, loss or damage can be accepted for parties using information given herein.


2013 ◽  
Vol 423-426 ◽  
pp. 852-856
Author(s):  
Jin Ping Pan ◽  
Xin Wei Zhu ◽  
Lian Jiang Tan

In the present paper, an effective method for detecting the cold weld defects in the thermal fusion weld of high-density polyethylene (HDPE) pipelines based on microwave technique is proposed. Using a microwave testing system, HDPE piping welds containing cold weld defects caused by insufficient heating time were examined by frequency sweep within the range of 9.2-9.9 GHz. At the frequencies that were most sensitive to the cold weld defects, the measured reflection coefficient S11 showed greatly different values between the good weld and those containing cold weld defects. The readily detectable differences in S11 value make the detection of the cold weld defects possible and feasible. This work provides insights for non-destructive testing of technical defects in HDPE piping welds.


2020 ◽  
Vol 1 (2) ◽  
pp. 96-106
Author(s):  
Amam Fachrur Rozie

LPG Storage Tank berkapasitas 50 Ton yang telah terinstalasi dan beroperasi sejak tahun 2010 akan dikaji kelayakan dan sisa umur pakai dari pressure vessel tersebut. Metode pengujian yang dipergunakan adalah Non-Destructive Testing (NDT) - Ultrasonic Testing (UT) pada bagian shell dan head untuk mendapatkan nilai actual thickness dari pressure vessel serta dilakukan Visual Examination. Nilai thickness tersebut dipergunakan untuk menganalisis dan mengkalkulasi thickness required (Treq), nilai Corrosion Rate (CR), Maximum Allowable Working Pressure (MAWP) serta umur sisa (Remaining Life) dari LPG Storage Tank tersebut. Dari hasil analisa serta perhitungan maka didapat umur sisa pakai dari LPG Storage Tank kapasitas 50 Ton adalah 18 tahun dengan nilai laju korosi sebesar 0,043 mm/thn


Author(s):  
Olivier Burat ◽  
Marc Piriou ◽  
Yann Kernin ◽  
Mikael Debroise ◽  
Christophe Moreau ◽  
...  

Reactor Pressure Vessel (RPV) Bottom Mounted Instrumentation (BMI) primary nozzle ultrasonic (UT) inspections have been performed by AREVA for more than 15 years. EPRI demonstrations were performed in 2004 and an RSEM qualification was obtained in 2005, This UT inspection detects and characterizes cracks in the base metal of the penetration and its interface with the weld. A complementary Visual Examination of the weld or an Eddy Current examination may also be performed but these tests are understood to be marginal with a possibility to miss indications or to mistake inclusions or weld voids for in-service cracks and therefore could force an unnecessary repair. Difficulties associated with examination of this area include: • Unpredictable ultrasonic behaviour in the weld material; • Wavy and complex OD weld surface profile; • Restricted accessibility around the weld surface. AREVA’s Non Destructive Examination Technical Center (NETEC), has developed and/or evaluated several techniques to improve surface and volumetric inspection of this weld including: • A TOFD ultrasonic (UT) probe to detect and characterize cracks within the weld metal from the ID surface of the nozzle. • A flexible UT Phased Array probe to accommodate the wavy and complex weld surface, in partnership with CEA, • Reduced surface ET probes and flexible ET multi-coils (in partnership with CEA), for improved surface inspection, • Infrared Photo-Thermal Camera examination of the weld surface. This paper discusses the designs and performances of these specific probes and NDT techniques as applied to the BMI nozzles, J-welds, and other similar components.


Author(s):  
John A. Trotter

Hemoglobin is the specific protein of red blood cells. Those cells in which hemoglobin synthesis is initiated are the earliest cells that can presently be considered to be committed to erythropoiesis. In order to identify such early cells electron microscopically, we have made use of the peroxidatic activity of hemoglobin by reacting the marrow of erythropoietically stimulated guinea pigs with diaminobenzidine (DAB). The reaction product appeared as a diffuse and amorphous electron opacity throughout the cytoplasm of reactive cells. The detection of small density increases of such a diffuse nature required an analytical method more sensitive and reliable than the visual examination of micrographs. A procedure was therefore devised for the evaluation of micrographs (negatives) with a densitometer (Weston Photographic Analyzer).


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