Time of Flight Diffraction (ToFD)

is an ultrasonic technique that can be used to examine welds in pressure vessels and pipework. ToFD can be employed to carry out corrosion mapping on pressure vessels and pipework. ToFD can also be used on heavy wall pressure vessels < 150mm in thickness; to detect critical flaws such as embedded cracking and lack of fusion. These defects may be missed by other inspection methods such as radiography, which have inherent limitations for example: reduced sensitivity on heavy wall material and time delays experienced during long exposures. ToFD does not have these limitations and is  able to assess critical areas at speeds that are faster than other inspection techniques.