BQCIS

Fast Surface Crack Detection for Welds

Eddy Current Testing (ET) offers a rapid and effective means of detecting surface-breaking cracks and discontinuities in conductive materials. It is especially valuable for weld caps and toes where fatigue cracks typically initiate, and it requires minimal surface preparation compared to dye penetrant or magnetic particle testing.

The method induces eddy currents into the weld surface using a probe containing a coil. Surface flaws distort these currents, causing changes in coil impedance which are displayed as distinctive signal responses. Advanced Eddy Current Array (ECA) probes enable wider, faster scans while producing intuitive C-scan images of defect locations and shapes.

BQCIS utilizes both conventional ET and ECA for weld screening on pipelines, tanks, offshore structures, and fabrication welds—ideal for coated surfaces or areas where wet inspection is not feasible.

Key ET Weld Inspection Activities

Calibration & Probe Selection

Selecting the optimal ET or ECA probe and frequency based on weld material and expected flaw types, followed by precise calibration using reference standards.

Weld Scanning & Signal Interpretation

Systematically scanning weld caps, toes, and heat-affected zones to interpret signal responses and identify surface-breaking flaws or discontinuities.

Key Benefits of ET for Welds

High Inspection Speed

High Inspection Speed

Enables rapid weld surface scanning, allowing large areas to be inspected far faster than conventional PT or MT methods.

Sensitive to Surface Cracks

Sensitive to Surface Cracks

Excellent detection capability for fine, shallow fatigue cracks or surface flaws at weld toes and caps.

Minimal Surface Prep

Minimal Surface Preparation

Can be performed through thin coatings such as paint, minimizing cleaning or coating removal requirements.

No Chemicals Required

No Chemicals Required

A dry, environmentally friendly inspection process requiring no penetrants or developers—ideal for clean or offshore environments.

Success Story

Eddy Current Array Speeds Up Offshore Weld Inspection

The Challenge:

An offshore operator needed fast screening of critical structural welds for fatigue cracking. Traditional MT/PT required excessive surface prep and drying time.

Our Solution:

BQCIS deployed advanced Eddy Current Array (ECA) probes capable of conforming to irregular weld shapes and scanning through paint, producing real-time C-scan maps.

The Result:

Inspection time was reduced by over 50%, while achieving reliable crack detection without coating removal. The digital data provided traceable, auditable results for the client’s integrity records.

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