An effective method for differentiating inside and outside defects of oil and gas pipelines based on additional eddy current in low-frequency electromagnetic detection technique

Lijian Yang, Ping Huang, Shi Bai, Songwei Gao, Teruyoshi Sasayama

Research output: Contribution to journalArticlepeer-review

Abstract

Accurate differentiation of whether the defect position is located on the inside or outside surface is necessary in the low-frequency electromagnetic detection technique (LFET) on oil and gas pipelines. We design a set of composite probe arrays that consisted of inductive magnetic coils (LFET coils) and eddy current testing (ECT) coils to accomplish comprehensive inspection, meanwhile, the theoretical calculation and analysis of the mutual interference mechanism between LFET and ECT coils were mainly implemented. Experimental result demonstrates that the ECT coils can effectively minimize the low-frequency magnetic field interference and allow low-frequency excitation coil setting parameters to be adjusted in a wide range (760 V Hz of voltage-frequency product in this experiment) to identify the inside defects above 1 mm depth while nothing found to detect outside defects. This circumstance enables the identification of the inside defect of 4 mm wide and 1 mm deep (10% wall thickness) at a lift-off value of 14 mm.

Original languageEnglish
Article number096505
JournalJapanese journal of applied physics
Volume59
Issue number9
DOIs
Publication statusPublished - Sep 1 2020

All Science Journal Classification (ASJC) codes

  • Engineering(all)
  • Physics and Astronomy(all)

Fingerprint Dive into the research topics of 'An effective method for differentiating inside and outside defects of oil and gas pipelines based on additional eddy current in low-frequency electromagnetic detection technique'. Together they form a unique fingerprint.

Cite this