Comparison of NDT Methods for Tubing
Any tubing inspection should be used in conjunction with a Hydrostatic, pneumatic, or Helium leak test prior to placing a component back into service.
| Eddy Current (ECT) | Remote Field (RFT) | XRFT | IRIS | Flux Leakage | |
|---|---|---|---|---|---|
| SPECIFICATIONS | |||||
| Material | Non-Ferrous | Ferrous | Ferrous | Both | Ferrous |
| Pull Speed | Fast (12X) | Medium (1.5X → 12X) | Slower (2X → 6X) | Slow (1.5X) | (12X max) |
| Tube Cleanliness | Clean | Clean | Clean | Very Clean | Clean |
| U-Bend Capable | Yes, Flexible | Yes, Flexible | Outer Radius |  |
|
| Wall Thickness Range | .022" → .135" | .028" → .300" | .049" → .120" | >.065" | .028" → .109" |
| DETECTION & LIMITATIONS | |||||
| Accuracy | ±10% | ±10% | ±10% | ±.003" | Limited |
| Flaws Under Tubesheet | Limited | |
ID Only |  |
|
| Flaws At or Adjacent to Baffle | Good | Limited | ID Only | Excellent | Good |
| Discern ID vs. OD Flaws | |
|
|
|
|
| Discern Through-Wall Hole | |
|
|
|
Limited |
| Axial Cracking | |
>50% | |
|
Limited |
| Circumferential Cracking | Array Only | >25% | |
|
Limited |