Acoustic Emission & Other NDT Inspection

Guided Ultrasonic Waves Pipe Inspection


Pipe inspection in the industry can prove difficult, expensive, time consuming and with limited results using common NDT techniques, such as UT Thickness. Other inspection techniques such as PIG may be impossible to apply for practical reasons, such as geometry.

Guided Ultrasonic waves provide a new solution for pipe inspection. The inspection is a very fast pipe screening technique which provides information about cross section area change in the pipe together with precise information a to where along the pipe this change occurs.


Download Brochure (828 kb, pdf)


How it works

  • A ring with the transducers is placed around the pipe

  • No couplant is required

  • Usually no surface preparation required

  • Instrumentation is fully portable

  • Guided waves are sent in each direction

  • Data are collected and stored in the portable instrument

  • Reflections are analysed and results reported immediately after the test

  • Long sections of pipe can be examined from one location, e.g. 30m on either side of the ring


  • Each test is completed within minutes including results

  • Can be performed at elevated temperatures without taking the pipe out of service up to 125C.

  • 100% of the pipe is inspected (within the diagnostic length of a test)

  • Pulse echo type operation provides information on feature position and approximate size

  • Sophisticated analysis aids interpretation of results

  • Minimum insulation removal for testing (1m)

  • Difficult-to-inspect areas (such as roadways) can be screened for defects

Small Diameter Pipes

  • Tested using solid rings

  • For pipes 2 - 8 inches diameter

  • Can be mounted in less than a minute

  • 4 inches clearance needed around pipe

Large Diameter Pipes

  • Tested using inflatable ring

  • For pipes 6 - 48 inches diameter

  • Employ conventional foot pump to inflate

  • 3 inches clearance needed around most of pipe

Two types of waves can be used


(twisting of the pipe)


(compression of the pipe)

A typical weld is completely symmetric and shows up as only a black curve

A typical corrosion patch is non-symmetric and is identified by the presence of a red curve


Target Applications

  • Rapid, full coverage screening of pipes

  • Especially cost effective in difficult to access locations
     Sleeved road crossings
     Corrosion under insulation
     Wall penetrations
     Pipe racks
     Rope access

  • Can detect local and general metal loss (greater than 5% of the cross-sectional area). Large cracks in welds may also be detected. Confirmation of the defect type and details sizing may be done with other NDT.