Major improvements in weld inspection are obtained using Phased Array technology with capability for beam steering, electronic scanning, focusing, and sweeping the ultrasonic beams. Electronic scanning is much faster than raster scanning, and can optimize angles and focusing to maximize defect detection. Pressure vessel (PV) inspections typically use “top, side, end” or “top, side, TOFD” views, though other imaging is possible. Special inspections can be performed, e.g., for specific defects, or increased coverage. Defects can be sized by pulse-echo as per code, by time-of-flight Diffraction or by back diffraction. New PV inspection codes, particularly ASME Code Case 2235, permit the use of advanced ultrasonic inspection techniques. Pipeline girth weld inspections use a unique inspection approach called “zone discrimination,” and have their own series of codes. While similar equipment is used in pipeline as in PV inspections, the pipeline philosophy is to tailor the inspection to the weld profile and predicted lack of fusion defects. Pipeline displays are specifically designed for near real-time data analysis. Both ASME CC 2235 and the pipeline codes permit the use of Fitness-For-Purpose, which reduces construction costs. Overall, phased array systems meet or exceed all PV and pipeline codes.

Standard calibration blocks to assess beam paths and configure data displays using ultrasonic instruments use low carbon steel with isotropic acoustic properties. However, industry is trending towards the use of high tensile steels where the acoustic prop....

Pulse-duration (ring-time) of the TOFD (Time of Flight Diffraction) lateral wave has been assumed to be based on the nominal frequency of the probe. With the improved damping used for TOFD applications, these probes now have had their ring-time reduced to about 1.5 cycles. As a result of the short pulse duration, the bandwidth of these probes is greatly increased. However, assumptions based on the nominal frequency are only approximations. Underlying physics of beam divergence exacerbate these assumptions when considering the frequency content of the lateral wave. CIVA simulations are used to illustrate how using the nominal probe frequency underestimates the actual dead zone extent of the lateral wave.

In the Introduction section, there is an added "w" in the word "wDNVGL", it should be removed and should only be presented as "DNVGL".

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