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Monitoring crack initiation and growth in a mockup vessel by acoustic emission
ND T Abstracts constructed on the basis of statistical data, obtained in uniaxial tensile experiments of the same type, they propose an approach predicting the threshold state of pressure vessels on the basis of AE signals received in the initial stage of loading the vessels.
piping, and U-anspo~on equipment. A recently developed procedure for testing railroad tank cars is reviewed in derail. In addition, the paper describes an application of AE for on-line leak detection monitoring of sulfuric acid plant heat exchangers.
50807 Anon. Technical documents for A E inspection Technical Diagnostics and Nondestructive Testing, Vol. 4, No. 1, pp. 67-72 (1992) The Department of Technical Diagnostics of the E.O. Paton Electric Welding Institute developed the Instructions for the AE Method of Testing Vessels Operating Under Pressure. This document conwols the application of the AE method and its introduction into practice will widen the range of application of this advanced method of instruction in testing structures and solve in certain cases problems which could not be solved previously. The preparation and training of personnel,proposed in this document, will widen the range of experts using the AE method, enable them to take scientifically justified and rational solutions on the state of inspected objects, and certify their qualifications.
50039
Sanghani, V.A.; Mody, A.I.; Patel, K.K.; Patel, P.D.; Murthy, C.R.L. Monitoring crack initiation and growth in a mockup vessel by 50787
acoustic emission Non-Destructive Testing 92. Proceedings of the 13th World Conference on Non-Destructive Testing, Sao Paulo (Brazil), 18-23 Oct. 1992. Vol. 1, pp. 89-93. Edited by C. HaUai and P. Kulcsar. Elsevier (1992) To develop and establish optimum test parameters for an actual field test, to understand the A E behaviour of known defects during a hydrotest, to study the source location ambiguities and inaccuracies and to identify the characteristics of AE sources such as cracks and leaks, a Real Time Failure Simulation was carried out on a carbon steel vessel of 600 mm diameter and 1500 mm length. The analysis of the data obtained revealed some locations which were active AE generators. Data patterns were also recorded and analysed pertaining to crack initiation from a single location to final failure and leakage.This paperdiscussesthe results of the test and demonstratesthe utility of AE monitoring during a hydrostatic test. 50784 Tschliesnig, P., Krenn, G.; Molla-Djafari, H.; Schauritsch, G. The acoustic correlation technique for the leakage testing of flat bottomed storage tanks Non-Destructive Testing 92. Proceedings of the 13th World Conference on Non-Destructive Testing, Sao Paulo (Brazil), 18-23 Oct. 1992. Vol. 1, pp. 104-108. Edited by C. Hallai and P. Kulcsar. Elsevier (1992) This paper shows the advantages of the normal Acoustic Emission Test (AET) compared with conventional tank inspection, which uses only visual and gauging techniques. But there exist still inconveniencies for the refineries and/or tank farms, especially caused by the required level variation. By the parallel application of the cross correlation, which is well known for the leakage testing of pipelines, the most disadvantages are overcome. 50569 Allevato, C.; Williams, J.D. Acoustic emission evaluation of Yankee dryer shell material Tappi Journal, Vol. 75, No. 7, pp. 69-74. (Jul. 1992) Structural pressure-containing parts in Yankee dryers are frequently subject to cracking creating problems for the pulp and paper industry. A feasibility study is reported here which aims to evaluate the suitability of acoustic emission (AE) as an inspection tool for Yankee dryers. Field and laboratory tests are described. AE emerges as a feasible alternative method of nondestructive evaluation, but other techniques would be needed in addition because of the limitations of AE. The AE technique detected and distinguished cracks and other flaws clearly in dryer shell material, as well as cracks in the actual dryers under hydrostatic and pneumatic conditions. Accurate source location and wide sensor spacing is possible because of the low attenuation rate for AE in grey cast iron. 50049 Fowler, TJ. Chemical industry applications of acoustic emission Materials Evaluation, Vol. 50, No. 7, pp. 875-882 (Jul. 1992) Acoustic emission (AE) has been found to be a reliable, cost effective indicator of structural problems and has developed into a mature nondestructive inspection technology. The method is widely used in the chemical industry and has led to significant improvement in equipment performance. The paper reviews use and development of AE-based test procedures for fiber-reinforced plastic and metal tanks, pressure vessels,
Dunegan, H.L. Acoustic emission testing of structures by use of mechanical waveguides 4th World Meeting on Acoustic Emission. (AEWG-35) 1st International Conference on Acoustic Emission in Manufacturing. Boston Massachusetts (United States), 16-19 Sep. 1991. pp. 110-117. Edited by S.J. Vahaviolos. A S N T (1991) Crack growth studies and leak detection in pressurized systems is now often undertaken using acoustic emission (AE) testing. Waveguides are often employed. An AE transducer is attached to a rod and the other end of the rod is bonded to the test structure. The experimental work reported in the paper involves AE testing with the use of just such mechanical waveguides.
49803 Batten, S.F. Acoustic emission monitoring of portable gas cylinders 4th World Meeting on Acoustic Emission. (AEWG-35) 1st International Conference on Acoustic Emission in Manufacturing. Boston, Massachusetts (United States), 16-19 Sep. 1991. pp. 170-179. Edited by S.J. Vahaviolos. ASNT (1991) To detect the presence of structural damageor corrosion in the wall of High pressure Portable Gas cylinders used to store gases such as CO2, Hydrogen, Oxygen etc. This paper investigates and compares the results obtained during a pneumatic and a Hydraulic pressure test, with the objective of setting a standard procedure and acceptance criteria for AEM testing of Portable Gas Cylinders during a pneumatic pressure test using the same gas as normally contained in the respective cylinder.
Hutton, P.H.; Kurtz, R.I.; Friesel, M.A.; Skorpik, J.R.; Dawson, J.F. Acoustic emission/flaw relationships for inservice monitoring of 49771
LWRs Battelle Pacific Northwest Labs., Richland, Washington (United States), NUREG/CR-5(>45/GAR, 119 pp. (Oct. 1991) The program concerning Acoustic Emission/Flaw Relationships for inservice Monitoring of LWRs was initiated in FY76 with the objective of validating the application of acoustic emission (AE) to monitor nuclear reactor pressure-containing components during operation to detect cracking. The program has shown the feasibility of continuous, on-line AE monitoring to detect crack growth and produced validated methods for applying the technology. Included are relationships for estimating flaw severity from AE data and field applications at Watts Bar Unit 1 Reactor, Limerick Unit 1 Reactor, and the High flux isotope Reactor. The report discusses the program scope and organization, the three program phases and the results obtained, standard and code activities, and instrumentation and software developed under the pro.gv:am. 49310 Hill, E.v.K. Burst pressure prediction in 45.7 C M (18 inch) diameter graphite/epoxy pressure vessels using acoustic emission data How Concept Becomes Reality, San Diego, California (United States). 15- 18 Apr. 1991. pp, 272-283. Edited by J. Stinson, R. Adsit and F. Gordaninejad. Vol. 36, Book 1, SAMPE (1991) An equation for predicting burst pressures in 45.7 cm (lg inch) diameter graphite/epoxy pressure vessels was generated from acoustic emission (AE) data taken during hydroproof. The AE data were all taken at or below 12.5% of the expectedburst pressure for the six bottles tested. Using the percentage of high amplitude (>70 dB) events, the linear equationwas able to predict burst pressures to within + or - 0.75 MPa (+ or - 109 psig) of the value given by the equation for a worst case 95% prediction interval. 48813 Wehrmeister, A.E. Detection of microbiological induced corrosion with unique
acoustic test technique NDT for Today's Applications, 1990 ASNT Fall Conference and Quality Testing Show, Seattle, Washington (United States), 18-12 Oct. 1990. pp. 64-67. ASNT (1990) The phenomenon known as Microbiologically induced corrosion (MIC), causes many problems of wall thinning and leakage as it attacks metals metals, such as pipes and tanks. Problems with MIC are known to be particularly acute where there is low, intermediate or no flow through the pipes. MIC cannot be successfully detected either by radiographic or conventional ultrasonic nondestructivetests. This paper proposes the use of acoustic emission (AE) testing using a thermal energy stimulus. This serves
NDT&E
International Volume 26 Number 6 1993
311
piping, and U-anspo~on equipment. A recently developed procedure for testing railroad tank cars is reviewed in derail. In addition, the paper describes an application of AE for on-line leak detection monitoring of sulfuric acid plant heat exchangers.
50807 Anon. Technical documents for A E inspection Technical Diagnostics and Nondestructive Testing, Vol. 4, No. 1, pp. 67-72 (1992) The Department of Technical Diagnostics of the E.O. Paton Electric Welding Institute developed the Instructions for the AE Method of Testing Vessels Operating Under Pressure. This document conwols the application of the AE method and its introduction into practice will widen the range of application of this advanced method of instruction in testing structures and solve in certain cases problems which could not be solved previously. The preparation and training of personnel,proposed in this document, will widen the range of experts using the AE method, enable them to take scientifically justified and rational solutions on the state of inspected objects, and certify their qualifications.
50039
Sanghani, V.A.; Mody, A.I.; Patel, K.K.; Patel, P.D.; Murthy, C.R.L. Monitoring crack initiation and growth in a mockup vessel by 50787
acoustic emission Non-Destructive Testing 92. Proceedings of the 13th World Conference on Non-Destructive Testing, Sao Paulo (Brazil), 18-23 Oct. 1992. Vol. 1, pp. 89-93. Edited by C. HaUai and P. Kulcsar. Elsevier (1992) To develop and establish optimum test parameters for an actual field test, to understand the A E behaviour of known defects during a hydrotest, to study the source location ambiguities and inaccuracies and to identify the characteristics of AE sources such as cracks and leaks, a Real Time Failure Simulation was carried out on a carbon steel vessel of 600 mm diameter and 1500 mm length. The analysis of the data obtained revealed some locations which were active AE generators. Data patterns were also recorded and analysed pertaining to crack initiation from a single location to final failure and leakage.This paperdiscussesthe results of the test and demonstratesthe utility of AE monitoring during a hydrostatic test. 50784 Tschliesnig, P., Krenn, G.; Molla-Djafari, H.; Schauritsch, G. The acoustic correlation technique for the leakage testing of flat bottomed storage tanks Non-Destructive Testing 92. Proceedings of the 13th World Conference on Non-Destructive Testing, Sao Paulo (Brazil), 18-23 Oct. 1992. Vol. 1, pp. 104-108. Edited by C. Hallai and P. Kulcsar. Elsevier (1992) This paper shows the advantages of the normal Acoustic Emission Test (AET) compared with conventional tank inspection, which uses only visual and gauging techniques. But there exist still inconveniencies for the refineries and/or tank farms, especially caused by the required level variation. By the parallel application of the cross correlation, which is well known for the leakage testing of pipelines, the most disadvantages are overcome. 50569 Allevato, C.; Williams, J.D. Acoustic emission evaluation of Yankee dryer shell material Tappi Journal, Vol. 75, No. 7, pp. 69-74. (Jul. 1992) Structural pressure-containing parts in Yankee dryers are frequently subject to cracking creating problems for the pulp and paper industry. A feasibility study is reported here which aims to evaluate the suitability of acoustic emission (AE) as an inspection tool for Yankee dryers. Field and laboratory tests are described. AE emerges as a feasible alternative method of nondestructive evaluation, but other techniques would be needed in addition because of the limitations of AE. The AE technique detected and distinguished cracks and other flaws clearly in dryer shell material, as well as cracks in the actual dryers under hydrostatic and pneumatic conditions. Accurate source location and wide sensor spacing is possible because of the low attenuation rate for AE in grey cast iron. 50049 Fowler, TJ. Chemical industry applications of acoustic emission Materials Evaluation, Vol. 50, No. 7, pp. 875-882 (Jul. 1992) Acoustic emission (AE) has been found to be a reliable, cost effective indicator of structural problems and has developed into a mature nondestructive inspection technology. The method is widely used in the chemical industry and has led to significant improvement in equipment performance. The paper reviews use and development of AE-based test procedures for fiber-reinforced plastic and metal tanks, pressure vessels,
Dunegan, H.L. Acoustic emission testing of structures by use of mechanical waveguides 4th World Meeting on Acoustic Emission. (AEWG-35) 1st International Conference on Acoustic Emission in Manufacturing. Boston Massachusetts (United States), 16-19 Sep. 1991. pp. 110-117. Edited by S.J. Vahaviolos. A S N T (1991) Crack growth studies and leak detection in pressurized systems is now often undertaken using acoustic emission (AE) testing. Waveguides are often employed. An AE transducer is attached to a rod and the other end of the rod is bonded to the test structure. The experimental work reported in the paper involves AE testing with the use of just such mechanical waveguides.
49803 Batten, S.F. Acoustic emission monitoring of portable gas cylinders 4th World Meeting on Acoustic Emission. (AEWG-35) 1st International Conference on Acoustic Emission in Manufacturing. Boston, Massachusetts (United States), 16-19 Sep. 1991. pp. 170-179. Edited by S.J. Vahaviolos. ASNT (1991) To detect the presence of structural damageor corrosion in the wall of High pressure Portable Gas cylinders used to store gases such as CO2, Hydrogen, Oxygen etc. This paper investigates and compares the results obtained during a pneumatic and a Hydraulic pressure test, with the objective of setting a standard procedure and acceptance criteria for AEM testing of Portable Gas Cylinders during a pneumatic pressure test using the same gas as normally contained in the respective cylinder.
Hutton, P.H.; Kurtz, R.I.; Friesel, M.A.; Skorpik, J.R.; Dawson, J.F. Acoustic emission/flaw relationships for inservice monitoring of 49771
LWRs Battelle Pacific Northwest Labs., Richland, Washington (United States), NUREG/CR-5(>45/GAR, 119 pp. (Oct. 1991) The program concerning Acoustic Emission/Flaw Relationships for inservice Monitoring of LWRs was initiated in FY76 with the objective of validating the application of acoustic emission (AE) to monitor nuclear reactor pressure-containing components during operation to detect cracking. The program has shown the feasibility of continuous, on-line AE monitoring to detect crack growth and produced validated methods for applying the technology. Included are relationships for estimating flaw severity from AE data and field applications at Watts Bar Unit 1 Reactor, Limerick Unit 1 Reactor, and the High flux isotope Reactor. The report discusses the program scope and organization, the three program phases and the results obtained, standard and code activities, and instrumentation and software developed under the pro.gv:am. 49310 Hill, E.v.K. Burst pressure prediction in 45.7 C M (18 inch) diameter graphite/epoxy pressure vessels using acoustic emission data How Concept Becomes Reality, San Diego, California (United States). 15- 18 Apr. 1991. pp, 272-283. Edited by J. Stinson, R. Adsit and F. Gordaninejad. Vol. 36, Book 1, SAMPE (1991) An equation for predicting burst pressures in 45.7 cm (lg inch) diameter graphite/epoxy pressure vessels was generated from acoustic emission (AE) data taken during hydroproof. The AE data were all taken at or below 12.5% of the expectedburst pressure for the six bottles tested. Using the percentage of high amplitude (>70 dB) events, the linear equationwas able to predict burst pressures to within + or - 0.75 MPa (+ or - 109 psig) of the value given by the equation for a worst case 95% prediction interval. 48813 Wehrmeister, A.E. Detection of microbiological induced corrosion with unique
acoustic test technique NDT for Today's Applications, 1990 ASNT Fall Conference and Quality Testing Show, Seattle, Washington (United States), 18-12 Oct. 1990. pp. 64-67. ASNT (1990) The phenomenon known as Microbiologically induced corrosion (MIC), causes many problems of wall thinning and leakage as it attacks metals metals, such as pipes and tanks. Problems with MIC are known to be particularly acute where there is low, intermediate or no flow through the pipes. MIC cannot be successfully detected either by radiographic or conventional ultrasonic nondestructivetests. This paper proposes the use of acoustic emission (AE) testing using a thermal energy stimulus. This serves
NDT&E
International Volume 26 Number 6 1993
311