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.