One of the most important applications for ultrasonic testing is inspection of welding, in particular welded steel plates (e.g. pipelines, vessels, ships etc.).
In the past ultrasonic testing was very often applied as a complement to X-Ray testing as some type of flaws were not detectable with X-Ray and vice versa. Today ultrasonic inspection is more widely used and becomes more important than the X-Ray technology, since new technologies have been applied which improves the detectability of flaws and provides extensive reports even with images representing the part inspected.
Phased Array equipment, combined with TOFD techniques are used with the aim to fully replace X-Ray one day.