Iris Internal Rotary Tube Inspection

The IRIS system is ideally suited to the inspection of carbon steel tubing although the technique can successfully be applied to all types of tube materials. Using high frequency pulse echo ultrasonic immersion scanning with a continuously rotating mirror ultrasonic pulses are emitted along a path perpendicular to the tube ID. Reflections are obtained from both the tube I.D and O.D, which then maps out the tube wall profile. When the probe is pulled through the tube length the pulses trace out a helical path on the wall which at the correct traverse speed gives 100% coverage of the tube. Since ultrasound does not pass through air the tubes must be filled with water to act as a couplant.

It is essential that the probe/mirror assembly is kept central in the tube. To achieve this, a centralizer with spring-loaded legs is utilized. This technique can detect defects with a diameter down to 1.5 to 2.0mm and defect depth can be measured to an accuracy of less than 0.1mm.

IRIS provides a perfect back-up to the Remote Field inspection technique. Specific tubes can be selected for inspection by IRIS to verify and correctly quantify the Remote Field inspection results.