Assessment of influence of surface crack-like stress concentrators on main pipeline operability

2021 ◽  
pp. 8-15
Author(s):  
Дмитрий Александрович Неганов ◽  
Евгений Евгеньевич Зорин ◽  
Николай Евгеньевич Зорин
Keyword(s):  
Surface Crack ◽  
Surface Defect ◽  
Surface Defects ◽  
Test Results ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Stress Concentrators ◽  
Trunk Pipeline ◽  
Non Destructive ◽  
Twofold Excess

Устранение поверхностных трещиноподобных дефектов типа «риска» на участках подводных переходов магистральных трубопроводов возможно методом вышлифовки на глубину до 20 % толщины трубы. Ранее было подтверждено, что в подводных условиях все основные методы неразрушающего контроля позволяют стабильно выявлять имеющиеся в зоне вышлифовки произвольно ориентированные поверхностные дефекты протяженностью от 20 мм и глубиной от 1,5 мм. Однако при меньших геометрических параметрах дефектов имеется вероятность их неполного устранения либо необнаружения. Для оценки возможности эксплуатации трубопровода с поверхностным дефектом с учетом принятых режимов диагностики проведены циклические испытания по критериям механики разрушений полноразмерных образцов с нанесенными в зоне вышлифовки поверхностными трещиноподобными концентраторами напряжений указанных размеров. Все группы образцов показали более чем двукратное превышение длительности инкубационного периода развития трещины по сравнению с количеством циклов нагружения, которое может испытать трубопровод за средний межинспекционный период эксплуатации. По результатам испытаний подтверждена возможность проведения ремонта поверхностных трещиноподобных дефектов типа «риска» на подводных переходах магистральных трубопроводов с различным сроком эксплуатации методом вышлифовки без установки кессона на ремонтируемый участок. Elimination of surface crack-like defects of the “risk” type on underwater crossing sections of trunk pipelines is possible by grinding to a depth of up to 20 % of pipe thickness. Previously, it was confirmed that in underwater conditions, all main non-destructive testing methods make it possible to stably identify randomly oriented surface defects in the grinding zone with a length of 20 mm and a depth of 1.5 mm. However, with smaller geometric parameters of defects, there is a possibility of their incomplete elimination or non-detection. To assess the possibility of operating a pipeline with surface defect, taking into account the accepted diagnostic modes, cyclic tests were carried out according to the fracture mechanics criteria of full-size specimens with surface crack-like stress concentrators of the indicated sizes applied in the grinding zone. All groups of samples showed more than a twofold excess of the duration of crack development incubation period in comparison with the number of loading cycles that the pipeline can experience during the average inter-inspection period of operation. Based on the test results, the possibility of repairing surface crack-like defects of the “risk” type at trunk pipeline underwater crossings with different service life by grinding without installing a caisson on the repaired section was confirmed.

scholarly journals The Defect Analysis of Carbonsteel Pipe Welding Connections Using Non-Destructive Testing with the Penetrant Test Method

2020 ◽  
Vol 5 (1) ◽  
pp. 38-47
Author(s):  
Nur Ichsan Sumardani ◽  
Ngainun Ibnu Setiawan ◽  
Bebeh Wahid Nuryadin ◽  
Dadan Sumardani
Keyword(s):  
Surface Defects ◽  
Welding Process ◽  
Test Method ◽  
Test Results ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Pipe Welding ◽  
Materials Used ◽  
Non Destructive ◽  
Penetrant Testing

In a welding process carried out on metallic materials is sometimes found defects in the material being tested, it is caused by many factors, such as the lack of good materials used and the lack of perfection of the welding process. At testing, it aims to know the surface defects in carbonsteel pipes to know the defects arising after welding. This test is performed with non-destructive tests (NDT) using Dye Penetrant testing method. This test uses 3 types of liquids, including; Cleaner, Penetrant, and developer. The results of these tests will then be observed whether defects occur after welding and what factors affect it. From the test, results there are known 10 locations defects on the surface of the carbonsteel pipe welding with a type of rounded indication of defects that are then followed up by re-welding on indications of such defects.

scholarly journals Non-destructive Testing of Wooden Elements

2021 ◽  
Vol 1203 (3) ◽  
pp. 032058
Author(s):  
Monika Zielińska ◽  
Magdalena Rucka
Keyword(s):  
Surface Defects ◽  
Test Methods ◽  
Ultrasonic Tomography ◽  
Test Results ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Near Surface ◽  
Thermal Techniques ◽  
Ground Penetrating ◽  
Non Destructive

Abstract Examining the condition of wooden elements is crucial from the perspective of proper structure performance. If the deterioration in the internal wood condition, which displays no symptoms visible from the outside, is detected, the further spread of the deterioration can be prevented. Test results often point to the necessity of conducting repairs and, renovations, replacing the structure of wooden beams, or even substituting a significant part of the structure. To achieve acceptable results, test methods should take into account the anisotropic nature of wood, which includes the shape of annual rings, as well as the location of the core in crosssection. To adopt methods based on physical effects, profound knowledge of wood physics is needed, particularly of interdependence. Apart from simple tests such as a visual inspection or tapping that are used to determine near-surface defects, non-destructive testing (NDT) plays an important role in the process. This paper presents the methods of non-destructive testing of wooden elements. These methods include tests conducted with ground penetrating radar (GPR), thermal techniques, microwaves, acoustic emission, ultrasonic tomography, and X-ray tomography. The paper summarises the use of non-destructive methods, indicating their advantages, disadvantages as well as some limitations.

Determination of parameters of surface defects for quality control of repair work on submerged crossings

2021 ◽  
pp. 554-561
Author(s):  
Олег Игоревич Колесников ◽  
Евгений Евгеньевич Зорин ◽  
Алексей Викторович Гейт ◽  
Игорь Игоревич Михайлов ◽  
Петр Сергеевич Голосов
Keyword(s):  
Quality Control ◽  
Nondestructive Testing ◽  
Surface Crack ◽  
Surface Defects ◽  
Control Technique ◽  
Non Destructive Testing ◽  
Testing Methods ◽  
Destructive Testing ◽  
Repair Work ◽  
Non Destructive

Внутритрубная диагностика позволяет обеспечить высокую выявляемость поверхностных трещиноподобных дефектов стенки трубопровода. Для их устранения в условиях проведения ремонтных работ на подводных переходах магистральных нефте- и нефтепродуктопроводов традиционно используется установка герметизирующей камеры, изолирующей дефектный участок и позволяющей в полной мере провести обследование области с опасным дефектом и дальнейший ремонт с применением методов неразрушающего контроля. Данная технология является безальтернативной, когда требуется вырезка-вварка катушки или другая сварочно-монтажная операция, однако представляется избыточной для устранения поверхностного дефекта методом вышлифовки. Современные технологии позволяют устранить поверхностный трещиноподобный дефект без установки герметизирующей камеры и тем самым значительно уменьшить трудоемкость и стоимость ремонта. Однако их широкое применение сдерживается отсутствием технической возможности проведения контроля качества отремонтированного участка под водой методами неразрушающего контроля с эквивалентной чувствительностью и выявляемостью относительно обычных условий. В этой связи выполнены экспериментальные исследования с целью определения пороговых значений параметров поверхностных трещиноподобных дефектов, выявляемых методами неразрушающего контроля в подводных условиях с учетом качества зашлифованной поверхности. Такие значения получены, в частности, для метода ультразвукового контроля с технологией фазированной решетки, модуляционного метода контроля с использованием вихретоковой матрицы, люминесцентного магнитопорошкового метода. Сформулированы требования к характеристикам оборудования для проведения неразрушающего контроля в условиях подводных работ. In-line diagnostics makes it possible to secure high detectability of surface crack-like defects of the pipeline wall. To eliminate them in conditions of repair work performed on submerge crossings of main oil and oil products pipelines, the installation of a sealing chamber is traditionally used to isolate the defective area and to enable a full-investigation of the area with a hazardous defect and further repairs, by non-destructive testing methods. This technology has no alternatives when cutting and welding of the coil or other welding and assembly operation is required, but it seems redundant for elimination of a surface defect by grinding method. Modern technologies make it possible to eliminate a surface crack-like defect without installing a sealing chamber and thereby can substantially cut manpower input and cost of repair. Their widespread use is deterred by the lack of technical possibility for quality control of the repaired area under water by nondestructive testing methods with equivalent sensitivity and detectability versus the normal conditions. In this regard, experimental research has been conducted to determine the threshold values of the parameters of surface crack-like defects detected by non-destructive testing methods in submerged conditions, taking into account the quality of the sanded surface. Such values were obtained, in particular, for the ultrasonic testing method with phased array technology, the modulation control technique using eddy current matrix, and the luminescent magnetic powder method. Requirements to performance characteristics of equipment for nondestructive testing in submerged operations have been formulated.

scholarly journals Increasing the laser-acoustic method efficiency for testing metal products by using 3D visualization

2019 ◽  
Vol 124 ◽  
pp. 03010
Author(s):  
I. R. Ismagilov ◽  
R. I. Kalimullin ◽  
A. N. Borisov
Keyword(s):  
Surface Defects ◽  
3D Visualization ◽  
Acoustic Method ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Testing Metal ◽  
Metal Products ◽  
Non Destructive

The article proposes a solution to the problem of increasing the efficiency of the laser-acoustic method of non-destructive testing. An approach to increasing the probability of detecting surface defects of microscopic dimensions in metals is considered. Due to the increased accuracy of determining defect parameters, the detail of 3D visualization of testing results was improved.

scholarly journals Physic perspective fusion of electromagnetic acoustic transducer and pulsed eddy current testing in non-destructive testing system

2020 ◽  
Vol 378 (2182) ◽  
pp. 20190608
Author(s):  
Wei Guo ◽  
Bin Gao ◽  
Gui Yun Tian ◽  
Dan Si
Keyword(s):  
Eddy Current ◽  
Surface Defects ◽  
Eddy Current Testing ◽  
Non Destructive Testing ◽  
Electromagnetic Acoustic Transducer ◽  
Destructive Testing ◽  
Current Testing ◽  
Pulsed Eddy Current ◽  
Acoustic Transducer ◽  
Non Destructive

Comprehensive non-destructive testing (NDT) for pipelines is a critical and challenging task. This paper proposes a novel physic perspective fusion NDT method of electromagnetic acoustic transducer (EMAT) and pulsed Eddy current testing (PECT) for detecting hybrid defects. This transceiver-integrated fusion sensor structure can simultaneously excite ultrasound and pulsed eddy current. Therefore, the generated ultrasound is applied to detect deep defects, while the eddy current detects surface defects. The theoretical derivation of EMAT and PECT fusion mechanism has been developed for analysis and interpretation of the results. In addition, numerical simulation on the detection of hybrid defects including surface defects with different width, depth and multiple bottom-thinning defects has been conducted. Experiments on both ferromagnetic and non-ferromagnetic material verify the feasibility of composite detection. Finally, tests have been validated on pipeline with weld defects, and the results show that the composite inspection method is capable of monitoring thickness variations and inspecting surface defects. This article is part of the theme issue ‘Advanced electromagnetic non-destructive evaluation and smart monitoring’.

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