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Ultrasonic Testing
IRIS 9000
Applications
IRIS 9000 turns heat exchangers inside out. It provides information such as type of defect (corrosion, erosion, pitting etc.) and its position within the length of the tube. This method is considered most accurate NDT inspection tool for heat exchangers, fin fans and boiler tubes.
Advantages
- 100% of tube circumference inspected
- Graphically displays a cross section of the tube wall, allowing the nature of the defect to be viewed
- Ability to inspect 12.2 mm (.50") I.D. up through 63.5mm (2.5") O.D tube
- Accurate thickness measurement to ±0.05mm (0.002”)
Principle
The IRIS 9000 employs an ultrasonic immersion pulse echo technique. The ultrasonic transducer is contained in a test head, which fits centrally into the exchanger or boiler tube. Ultrasonic pulses are emitted along a path parallel to the tube axis. The pulses are reflected radially on to the tube wall by a rotating 45° mirror. Reflections from the inner and outer walls follow the same path back to the transducer. The time interval between the first echo from the internal surface of the tube and the first echo from the outside surface of the tube can be used to represent the tube wall thickness.
As the mirror rotates, the ultrasonic beam is traversed around the tube circumference and each successive pulse is mapped out as a horizontal scan line on the screen of the IRIS 9000. There are 192 readings per revolution and 2,400 revolutions per minute. When the probe is advanced along the tube at the optimum inspection rate, the ultrasonic pulses paint a helical path on the tube wall ensuring 100% coverage.
Phased Array
Applications
The Phased Array X-32 ultrasonic machine is a very powerful NDT tool that provides extremely accurate inspection results for industries such as petrochemical & refinery, nuclear & power stations, pulp & paper and structures (bridges). The technology is used for numerous applications that require ultrasonic evaluations including weld quality inspections on reactors, pressure vessels and boilers or on shafts, pins, bolts, plate, etc.
Principle
The Phased Array unit uses multiple angles of ultrasonic beams simultaneously that can be electronically steered to evaluate specific areas and depths. It is a hand held user-friendly unit, which can complete multi-angle and multi-depth inspections simultaneously with one probe. The phased array system is also cost effective by reducing the inspection time compared to traditional ultrasonic methods. This unit uses 32 active elements for high volume resolution to precisely size and map flaws. The X-32 data acquisition software can provide a real time recording of pertinent flaw information and also print out hardcopies of defects for future reference. In some cases, this technology could eventually replace the hazardous radiography method.
Hartford Wedge
Applications
The Hartford Wedge allows ultrasonic thickness readings of cast-iron components, typically dryer roll shells and deaerators.
Principle
The Wedge is an ultrasonic testing system that effectively solves the problem of sonic velocity discrepancies in non-homogenous components. Since the measured thickness is dependent on sonic velocity, significant errors can arise when cast irons have a velocity range of as much as 30%.
Inside the Wedge is a pair of transducers that are set up as opposing angle beam transducers. Separated by a fixed distance, they send and receive a longitudinal wave through a material parallel to the surface. The transducers operate in through-transmission mode and use a time-of-flight measurement to produce a sonic velocity number with arbitrary units for the component and the standard. These figures are compared and the ultrasonic instrument is adjusted accordingly.
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