May 25, 2017
The Truth Behind Composite Inspection Methods: A Final Look

Posted by: Jaclyn Deter

As composite repair solutions are typically only researched at the point that a repair becomes a necessity, many find themselves in the dark on the details of the processes, materials and equipment used in the repair application. However, what is more widely known is the necessity of functional pipes and pipelines that meet federal requirements and are capable of being inspected.   

We’ve found that some manufacturers have targeted this purchasing group and have begun to describe their composite repair products as “inspectable,” implying that other brands may not be capable of inspection and therefore incapable of meeting regulations.

Over the course of our four previous articles on this subject, we’ve dispelled this myth. Not only are there other companies that manufacture inspectable composite repair materials, but most, if not all, of the materials used in today’s repair applications are capable of being inspected, and by several unique methods. We covered these methods in the previous articles of this series:

Part 1: Ultrasonic Testing

  • Phased Array: This form of ultrasonic non-destructive testing (NDT) uses dozens of independently pulsing transducers that can be swept at a variety of angles to locate defects. This method can be used to inspect both the bond line and in the pipe wall.
  • EMAT: Also a form of ultrasonic NDT, EMAT inspects pipes and composites by producing electromagnetic waves that interact with particular conductive materials found in some composite repairs that give off their own electromagnetic waves. The combination of these uniquely produced electromagnetic waves creates sounds waves that are used to locate damages and defects.

Part 2: Pulsed Eddy Current and Radiographic Testing

  • Pulsed Eddy Current: This NDT method, based upon Faraday’s Law of Magnetic Induction, is an electromagnetic testing method that measures the strength of eddy currents to detect defects in conductive materials. This method can be used to inspect the underlying pipe wall through the composite.
  • Digital Radiography: Also known as X-ray, this method uses penetrating radiation to inspect delamination and disbonding within the materials being tested. This method can find defects in both the composite and in the pipe wall.

Part 3: Microwave and Thermography Testing

  • Microwave: This method is used to detect defects such as delamination and gouges in nonmetallic materials, making it possible to view surface defects of steel pipe underneath a composite repair.
  • Thermography: By detecting the change in thermal activity within a material, thermography can find defects by creating a heat map of the surface of a stressed object. This method can find defects within the composite.

These methods make up six of the more commonly used testing methods today and show the variety of pipe and composite inspection available to asset owners so that they might chose a method more appropriate for their specific situation.

We invite you to read our series from the beginning or follow the links above to each part of the series. For more answers to your composite inspection-related questions, contact Milliken Infrastructure’s Jim Souza or Myles Johnson

Category: Feature Articles


Leave a Comment