TY - JOUR
T1 - 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
AU - Yang, Lijian
AU - Huang, Ping
AU - Bai, Shi
AU - Gao, Songwei
AU - Sasayama, Teruyoshi
PY - 2020/9/1
Y1 - 2020/9/1
N2 - 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.
AB - 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.
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U2 - 10.35848/1347-4065/abaf0c
DO - 10.35848/1347-4065/abaf0c
M3 - Article
AN - SCOPUS:85091876563
VL - 59
JO - Japanese Journal of Applied Physics, Part 1: Regular Papers & Short Notes
JF - Japanese Journal of Applied Physics, Part 1: Regular Papers & Short Notes
SN - 0021-4922
IS - 9
M1 - 096505
ER -