A Novel Method for Crack Detection of Oil Docks and Offshore Structures and Equipment through Insulation and Protective Coatings

Document Type : Research Paper

Authors

1 School of Mechanical Engineering, Iran University of Science & Technology

2 Chief District National Iranian Oil Products Distribution Company, Fars Region

Abstract

One of the main problems in oil docks and offshore stuctures is the initiation of small cracks in fitting places. Maintenance engineers have always looked for a method to detect the crack at an early stage before crack growing and critical conditions initiate. Although several non-destructive testing methods have been proposed for the inspection of these structures, removing insulating layer and protective coating makes these methods inappropriate and expensive. In this paper, a new non-destructive pulse eddy current method is used to detect and characterize fine cracks under insulation layer without separating and removing the insulation from the structure. First, the theory of pulse eddy current method is briefly explained and then the pulsed eddy current test is carried out on a steel plate having several simulated cracks with different depths. The results of the tests on the test plates with insulation layers and without insulation layers are presented and compared

Keywords

References

مراجع
[1]. رضا دادخواه س. و دادخواه ا.، تکنولوژی بازرسی جوش، نشر آزاده، 1385.
[2] McMaster R. C., Nondestructive testing handbook, 2 ed., vol Testing ,1986.
[3] Tian G. Y., and Sophian A., “Defect classification using a new feature for pulsed eddy current sensors”, NDT & E International, vol. 38(1), pp. 77-82, January 2005.
[4]. Safizadeh M. S., Lepine B. A., ForsythVz D. S and Fahr A., “Time-frequency analysis of pulsed eddy current signals”, Journal of Nondestructive Evaluation, Vol.20, No. 2, PP. 73-86, June 2001.
[5]. صفی زاده م.س. و حسنیان م.، شبیه‌سازی مکانیزم تست خوردگی، تعیین و تشخیص میزان خوردگی لوله‌های گاز از روی عایق با به کارگیری آزمون غیر مخرب جریان گردابی گذرا، مجله علمی پژوهشی نفت، شماره 63، صفحه 3-11.
[6]. صفی زاده م.س. و حسنیان م.، کاربرد آزمون جریان گردابی گذرا جهت تست ضخامت سنجی مقاطع، کنفرانس ساخت و تولید بابل، 10-12 اسفند 1388.
[7]. WWW. Ndt.org excitrd 6 Oct 2009.
[8]. Riccardo Scottini Herman J. “Inspection of Coated Subsea piping and risers Quakkelsteijn Applus RTD”, American Society for Nondestructive, pp. 4-27. 2007.
[9]. Tian G Y., and Sophian A,. “Reduction of lift-off effects for pulsed eddy current NDT”, NDT & E International, pp. 319–324, 2004.
[10]. Giguere S., Lepine B. A.., and Dubois J. M. S. “Pulsed Eddy Current Technology: Characterizing Material Loss with Gap and Lift-off Variations”, Res Nondestr Eval ,pp. 119–129,2001.
Journal of Petroleum Research
Volume 22, Issue 72 - Serial Number 72
January and February 2013
Pages 30-37

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