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MFL

Magnetic Flux Leakage Testing (MFL) Services

Magnetic Flux Leakage uses strong magnets to detect wall loss and corrosion in pipelines and storage tank floors.

What is Magnetic Flux Leakage Testing?

Magnetic Flux Leakage (MFL) is a widely-used NDT method for inspecting ferromagnetic materials, particularly in pipeline and storage tank applications. A strong magnetic field is applied to the material, and sensors detect flux leakage caused by wall thickness reductions, corrosion, or other defects. MFL is commonly used in pipeline pigging operations for inline inspection.

How MFL Works

1

Strong magnetic field saturates the test material

2

Wall loss causes magnetic flux to leak from surface

3

Hall effect sensors or coils detect flux leakage

4

Signal analysis determines defect severity

Applications of Magnetic Flux Leakage Testing

Pipeline inline inspection (pigging)
Storage tank floor scanning
Wire rope inspection
Heat exchanger tubing
Well casing inspection

Advantages

  • Fast scanning speed
  • No couplant required
  • Can inspect through coatings
  • Automated inspection possible
  • Good for large-area scanning
  • Established pipeline inspection method

Limitations

  • Only works on ferromagnetic materials
  • Sensitivity affected by scanning speed
  • Difficult with thick materials
  • Cannot determine exact defect depth
  • Strong magnets create handling challenges

Applicable Standards & Codes

API 1163
ASTM E2905
ASME B31.8S
NACE SP0102
API 650 Annex K

Industries Using MFL

Oil & Gas
Pipeline
Storage
Manufacturing

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