New directions in guided wave pipe testing

The brief review of the most recent developments in long range ultrasonic guided wave testing of pipeline was presented. The benefits of phased array focusing of the guided waves and benefits of using both torsional and longitudinal guided wave modes for testing were discussed. The phased array focusing of ultrasonic guided waves is one of the recent and fastest evolving areas in the ultrasonic nondestructive testing of pipeline. A phased array is a fixture containing sets of transducers that wrap around the circumference of a pipe. Many pipeline tests performed with ultrasonic guided waves make use of only a single mode type, torsional or longitudinal. Circumferential displacement profiling can also be used to locate the circumferential position of a discontinuity by focusing energy around the entire circumference of a pipe at a particular axial location. Discontinuities would manifest as a large increase in the amount of energy being reflected from a particular region.