Carbon Steel Fin-Fan Tubes Near-Field Array (NFA) Integrity Evalutions
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.
- NFA results are displayed in C-scan images.
- High Resolution Displays assist in better analysis
- Tube must be free of scale and debris. Calibration is based off custom NFA Standards that include different size diameter pits.
- Can only be used to inspect carbon steel.
- Identifies only ID losses.