Phased array ultrasonic inspection is a technique for volumetric assessment and flaw detection in metal objects.  Phased arrays consist of a number of ultrasonic elements arranged in a single instrument.  The multiple elements are used to create an ultrasonic beam.  The beams can be “steered” to optimize the orientation of the beam to the object being studied, which increases the probability of detection of flaws in certain features, such as longitudinal welds in piping.  The beams also can be scanned over the object in order to produce an image.  By adjusting the individual elements electronically, the beams also can be focused to yield more clear and less uncertain results. 

Portable phased array ultrasonic instruments offer advantages over conventional single-element ultrasonics, particularly in testing of automated welds in piping.  Operating in scanning mode and using the electronic focusing capabilities of these systems, phased array ultrasonics are significantly faster than single-element systems. 

Quest Reliability owns a phased array ultrasonic system, and has several years of experience in the use of this system to evaluate longitudinal seam welds and thick walled vessels in petrochemical and power generation plants.

There are numerous applications for which phased array ultrasonics is useful.  Some examples include:

• Flaw (discontinuity) detection in steel plate or thick-walled vessels
• Longitudinal seam weld testing
• Axial stress corrosion cracking in pipes
• Butt weld testing
• Nozzle corrosion testing
• Stress corrosion cracking in turbines
• Stepwise hydrogen induced cracking

For further information on Phased Array UT please contact us.