Carbon Steel Fin-Fan Tubes Near-Field Array (NFA) Integrity Evalutions

NFA INSPECTION
IRISNDT offers NFA tubular inspection services to inspect the ID of carbon steel fin-fan tubes. NFA tubular inspections use multiple individual coils grouped together instead of the single coil used in standard near-field testing (NFT). NFA uses two rows of receiver coils to provide 360º coverage of the ID of finned tubes.

IN COMPARISON TO NFT INSPECTIONS, NFA:

  • Collects data for a larger tube area in a single pass.
  • Is more sensitive to ID small volumetric flaws.
  • Is better at sizing ID flaws.
  • Is more sensitive to circumferential cracks.

 

 

 

 

 

 

 

 

 

 

 

IRISNDT APPLIES NFA:

  • To identify ID general corrosion.
  • To identify ID erosion.
  • When satisfactory cleaning, needed for techniques such as Internal Rotary Inspection System (IRIS), is not achievable.

FEATURES

  • NFA results are displayed in C-scan images.
  • High Resolution Displays assist in better analysis

INSPECTION PREPARATION

  • Tube must be free of scale and debris. Calibration is based off custom NFA Standards that include different size diameter pits.

LIMITATIONS

  • Can only be used to inspect carbon steel.
  • Identifies only ID losses.

Carbon Steel Fin-Fan Tubes Near-Field Array (NFA) Integrity