Inner Detection of Corrosion by Ultrasonic Phased Array in Underground Compressed Natural Gas Storage Well

Author(s):  
Cunjian Miao ◽  
Weican Guo ◽  
Zhangwei Ling ◽  
Ping Tang

Compressed natural gas (CNG) storage well is a kind of pressure vessel buried underground. The detection of corrosion, which may be induced by the surrounding soil and different medium, is important for the safety security of the well, and protects it from CNG leakage or casing explosion. Among non-destructive examination techniques for corrosion detecting, the ultrasonic techniques are popularly utilized, in which the phased array approach can offer distinct advantages. To investigate both reliability and applicability of the phased array technique in the storage well, a complex design with a 512-element ultrasonic phased array that covered the entire cross-section was discussed, and phased array parameters were determined, including array elements, array element size, ultrasonic frequency and so on. An ultrasonic testing system was designed based on the above design, including a frame for holding phased array probes, a specific vessel for storing ultrasonic cards and other components, and an in-pipe robot designed for instruments’ moving in the storage well. The general corrosion condition described by thickness images were captured by the ultrasonic testing system with B, C and D-scan functions, in which circumferential electronic linear scanning was performed by the phased array probes and axial scanning was done by a mechanical scanning device. A method for minimizing the external pressure from water column necessary for coupling was put forward in the scanning and detection process. The sample for CNG storage well with artificial defects was built in laboratory environments and experiments were conducted to validate detection effects, and the phased array technique provided good sensitivity and efficiency, which may lead to a successful application in CNG storage well examination.

Author(s):  
Weican Guo ◽  
Shengjie Qian ◽  
Zhangwei Ling ◽  
Dongsheng Hou

The tube to tube-sheet weld is the main connection structure of heat exchanger. This paper presents the phased array ultrasonic technique for testing the tube to tube-sheet welds of heat exchanger. The optimization analysis of phased array parameters and the simulation on the acoustic field with CIVA software were completed. The mentioned phased array parameters included array elements, array element size, deflection angle, ultrasonic frequency and so on. An ultrasonic testing system was designed and fabricated in accordance with the structure of heat exchange tube and fillet welds position. The ultrasonic C-scan was carried out by the ultrasonic testing system with its circumferential scanning by a mechanical scanning device while the axial electronic linear scanning by the phased array probe. At last, tests on samples with the porosity and incomplete fusion flaws were performed by the ultrasonic testing system. Experimental results showed that the phased array ultrasonic technique could effectively detect the porosity flaws and the incomplete fusion flaws in the tube to tube-sheet welds of heat exchanger.


Author(s):  
Yutaka Matsui ◽  
Yukinori Iizuka ◽  
Masahito Suzuki ◽  
Eiichi Urahata ◽  
Tomohiro Inoue ◽  
...  

A high sensitivity ultrasonic testing system for inspection of the weld seam of ERW pipes was developed. The factors that affect the quality of the weld seam were investigated using an ultrasonic C-scan method with a focused probe and samples sliced from weld seams. As the result, it was found that a scattered-type penetrator consisting of micro oxides is a key factor in the quality of the weld seam. Absorbed energy in the Charpy impact test can be evaluated by the ultrasonic echo amplitude with the optimized focused beam size (about 1mm2) to detect the scattered-type penetrator. In order to evaluate the density of the scattered-type penetrator in weld seams with the optimum focused beam size for pipe, a point focused beam tandem method was developed by applying the ultrasonic phased array technique. The sensitivity of the developed method is 20dB higher for a standard artificial through drilled hole whose diameter is 1.6mm. A precise seam tracking system was also developed for application of the point focused beam tandem method to the actual ERW pipe manufacturing process. Since the allowance for applying the focused beam to the weld seam is very narrow, i.e., about 1mm, a circumference multi-point simultaneous receiving technique and thermal image-type seam detection technique were developed. The developed ultrasonic testing system has been in operation at the 24″ ERW mill at East Japan Works (Keihin District) of JFE Steel Corporation since March 2011. The combination of the ultrasonic testing system and an oxide control technique now contributes to production of high-performance, high-quality ERW pipe “Mighty Seam®” for use in frigid environments.


Author(s):  
Paul A. Meyer

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.


2019 ◽  
Vol 5 (3) ◽  
Author(s):  
Jiri Hodac ◽  
Pavel Mares ◽  
Jaromir Janousek ◽  
Martin Linhart

This work is designed to artificially create test specimens with flaws that behave the same way as real-function flaws when observed by nondestructive testing (NDT) technologies. Thus, the understanding of the detection limitations of NDT methods is needed. In this study, real, realistic, and artificial flaws were compared by ultrasonic phased array technology. Fatigue flaws, which belong to the most common structural issues (Ruzicka, M., Hanke, M., and Rost, M., 1987, Dynamicka Pevnost a Zivotnost, CVUT, Prague, Czech Republic, p. 75), are investigated. Measurements have revealed significant differences in the amplitude of ultrasonic echo from fatigue cracks in distinct phases of crack propagation. Studied specimens with realistic flaws have demonstrated their quality for calibration, staff training, and NDT system qualification. More realistic test specimens will increase ultrasonic test result reliability.


NDT World ◽  
2016 ◽  
Vol 19 (3) ◽  
pp. 17-27
Author(s):  
Нурматов ◽  
Islam Nurmatov ◽  
Лапидус ◽  
Aleks Lapidus ◽  
Пасси ◽  
...  

Introduction. The approach and practical implementation for the sensitivity calibration and its equalizing within entire insonified cross-section of the material have been presented in the article for 3 most common reference artificial reflectors, namely the flat bottom hole (FBH) situated at parallel to the weld bevel plane, the EDM notch (N), and the side drilled hole (SDH). The method. The issue of inhomogeneous sensitivity over cross-section covered through phased array (PA) sectorial scan plan is due to several factors, which are highlighted and explained. 5 of them are independent on the reference reflector’s shape. In addition the FBH and N reference reflectors are characterized by the strong dependency of the echo amplitude on the angle, under which the ultrasonic wave hits their surface (factor 6, which differs the FBH and N from the omnidirectional SDH). The approach for equalizing the sensitivity over sectorial-scan-insonified cross-section of the material for all types of reference reflectors has been proposed and explained. It is based on the ability of ultrasonic PA flaw detector to implement each pulsing-receiving cycle among the plurality of the scan-plan-forming set of focal laws with individually and independently settled gain and other key settings including Distance Amplitude Correction / Time Corrected Gain (DAC / TCG). The Sonotron NDT’s ISONIC Series PA instruments (ISONIC 3510, ISONIC 2010, and ISONIC 2009 UPA Scope) are featured with the said ability uniquely: in the said units the DAC / TCG mechanism is used purely for compensating the dependency of echo amplitude on the material travel distance while the feature of varying Gain per Focal Law is utilized just for the forming of easy-reproducible Angle Gain Compensation (AGC) plan. Both the DAC / TCG and AGC plans are created independently on each other with use of the same reference reflectors. The results. Combining of the independent DAC / TCG and AGC mechanisms for the first time ever provides the equalizing of the sensitivity for all types of reference reflectors independently on their X, Y position over the entire cross-section of the material — this is confirmed by a number of experimental results presented. Conclusion. At last the single group sectorial scan only becomes sufficient for the complete coverage of the whole cross-section of the weld. This allows reducing the dimensions of required PA probes and wedges in use and the width of the area for the scanning along the fusion line. And finally this increases the maximal possible speed of scanning along with reducing of the inspection cost.


NDT World ◽  
2019 ◽  
pp. 37-41
Author(s):  
Алан Колдер ◽  
Alan Caulder

Full matrix capture and the total focusing method are considered by many NDT experts to be the next major improvement to phased array ultrasonic testing. This article showcases some advantages the new techniques offer compared to the capabilities of traditional ultrasonic phased array.


Author(s):  
Shaojun Wang ◽  
Xiaoying Tang ◽  
Pan Song ◽  
Bin Ren ◽  
Yaozhou Qian ◽  
...  

Responding to non-conductive, non-magnetic material characteristics of polyethylene (PE) pipe, this paper comes up with the ground penetrating radar (GPR) detection for urban PE gas pipeline visualization research in order to solve the problems of positioning difficulty, and to avoid potential safety hazards caused by undefined positioning of PE pipeline, so that it can provide some experience to the application of position detection technology to locate buried polyethylene pipeline. Responding to the special material properties and welding form and based on the analysis of traditional ultrasonic testing for polyethylene butt-fusion joint, this paper comes up with an ultrasonic phased array dynamic focusing and S scanning imaging technology, to make a testing experiment on polyethylene butt-fusion joint. Results of the phased array ultrasonic testing of cracks in polyethylene butt-fusion joints shows that the testing method is feasible, and verifies the buried polyethylene butt-fusion joints engineering. This research would provide experience to the application of ultrasonic phased array technology in buried polyethylene pipeline inspection.


2011 ◽  
Vol 127 ◽  
pp. 214-219
Author(s):  
Xiao Lei Che ◽  
Cheng Zhu ◽  
Nai Dan Wang

This paper illustrates an intelligent testing system, designed in the requirement for the testing of compressed natural gas engine ECU. This system is a virtual environment for ECU’s testing and debugging, it provides all kinds of sensor signals, switch signals and various simulated actuators for ECU. PC can configure the system’s settings and receive testing results through USB. When receiving testing datum, PC judges whether ECU is in normal status according to the datum and saves them in files. Consequently automatic testing is realized.


Author(s):  
Aaron A. Diaz ◽  
Anthony D. Cinson ◽  
Susan L. Crawford ◽  
Traci L. Moran ◽  
Michael T. Anderson

A set of circumferentially oriented thermal fatigue cracks (TFCs) were implanted into three cast austenitic stainless steel (CASS) pressurizer (PZR) surge-line specimens (pipe-to-elbow welds) that were fabricated using vintage CASS materials formed in the 1970s, and flaw responses from these cracks were used to evaluate detection and sizing performance of the phased-array (PA) ultrasonic testing (UT) methods applied. Four different custom-made PA probes were employed in this study, operating nominally at 800 kHz, 1.0 MHz, 1.5 MHz, and 2.0 MHz center frequencies. The CASS PZR surge-line specimens were polished and chemically etched to bring out the microstructures of both pipe and elbow segments. Additional studies were conducted and documented to address baseline CASS material noise and observe possible ultrasonic beam redirection phenomena.


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