Journal of the Korean Society for Nondestructive Testing (비파괴검사학회지)

The Korean Society for Nondestructive Testing (한국비파괴검사학회)
권호 표지

Development of MFL Testing System for the Inspection of Storage Tank Floor

저장탱크 바닥면 검사를 위한 누설자속 탐상 시스템 개발

  • 원순호 (한국기계연구원 비파괴평가그룹) ;
  • 조경식 (한국기계연구원 비파괴평가그룹) ;
  • 이종오 (한국기계연구원 비파괴평가그룹) ;
  • 장홍근 (고려공업검사㈜) ;
  • 주광태 (고려공업검사㈜)
  • Published : 2002.02.28
Download PDF
⟨ Previous Next ⟩

Abstract

MFL method is a qualitative inspection tool and is a reliable, fast and economical NDT method. The application of MFL method to the inspection of storage tank floor plates has been shown to be a viable means. Examination of tank floors previously depended primarily upon ultrasonic test methods that required slow and painstaking application. Therefor most ultrasonic inspection of storage tank has been limited to spot testing only. Our NDE group have developed magnetic flux leakage system to overcome limitation of ultrasonic test. The developed system consists of magnetic yoke, array sensor, crawler and software. It is proved that the system is able to detect artificial flaw like 3.2mm diameter, 1.2mm depth in 6mm thick steel plate.

누설자속법은 신뢰성과 경제성을 충족시키면서 정성적인 결과를 제공하는 비파괴시험법이다. 특히 저장탱크바닥판의 검사에 효과적으로 적용될 수 있음을 보여주었다. 이전에 저장탱크 qkekrvis의 검사에 사용되었던 초음파탐상법은 검사속도가 느리고, 적용에 따른 어려움으로 국부검사에 한정되어 왔다. 본 연구팀은 이러한 초음파탐상의 단점을 극복하고자 누설자속탐상법을 개발하였다. 개발된 시스템의 주요부분은 누설자속 발생부, 어레이센서, crawler 및 운용프로그램으로 구성되어 있고, 최종적으로 개발된 시스템이 6mm강판에서 ${\psi}3.2mm,\;d\;1.2mm$와 같은 인공결함을 검출할 수 있음을 보여주었다.

Keywords

References

  1. API Standard 653 : Tank Inspection, Repair, Alternation, and Reconstruction, 2nd ed, American Petroleum Institute, Dec. (1995)
  2. API Recommended Practice 575 : Inspection of Atmospheric and Low-Pressure Storage Tanks, 1st ed., American Petroleum Institute, Nov. (1995)
  3. Mk2 Floorscanner Manual, AEA Technology plc., (1997)
  4. C. Edwards and S. B. Palmer, The Magnetic Leakage Field of Surface-Breaking Cracks, J. Phys, D: Appl. Phys, Vol.19, pp. 657-673 (1986)
  5. M. J. Bergander, Magnetic Flux Leakage Examination of Petro/Chemical Heat Exchanger Tubing, ASNT's ICPIIT III Topical Conference, pp. 95-102, June (1993)
  6. J. B. Nestleroth, T. A. Bubenik and G. L. Ridderbusch, A Review of Magnetic Flux Leakage Technology for the In-Line Inspection of Gas Transmission Lines, Proceeding International Conference on Pipeline Inspection, paper IV-5, June (1991)
  7. D. E. Bray and D. Mcbride, Nondestructive Testing Technique, pp. 421-447, John Wiley & Sons Inc., (1992)
  8. Z. You and D. Bauer, A New Technique for Inspection Top and Bottom Sides of Tank Floors, ASNT's ICPIIT IV Topical Conference, pp. 227-231, June (1995)
  9. D. M. Amos, The Truth about Magnetic Flux Leakage as Applied to Tank Floor Inspections, ASNT's ICPIIT IV Topical Conference, pp. 232-236, June (1995)
  10. B. W. Maxfield, P. C. Fitzgerald, A Quantitative Magnetic Flux Leakage Instrument and Its Application to Tank Bottom Corrosion Assessment, ASNT's ICPIIT IV Topical Conference, pp. 237-241, June (1995)
  11. Z. S. Lim and G. H. Kim, Development of an Automatic Inspection System for Minute Defects in Steel Strip, FENDT '97, pp. 305-311, Oct. (1997)