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Acoustic Emission
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Ground Penetrating Radar
TWISTED TUBE® Inspection Services
ANDT Solutions for Oil & Gas
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NDT Piping Inspection


CUI (Corrosion Under Insulation) Videos CUI Program Video
Click here to view our Corrosion Under Insulation (CUI) Program video

The goal of piping system inspection is to increase the reliability of the system by increasing the mean run time to failure. In order to achieve this, an owner must utilize the proper inspection technique based on the associated damage mechanism. Utilizing point to point ultrasonic thickness readings is relatively useless if the owner is concerned about localized corrosion. Proprietary techniques such as a Touch Point Corrosion ultrasonic methodology and On-line monitoring of suspect lines are available through MISTRAS.

In addition to damage mechanisms, accessibility to the piping becomes a determining factor in the choice of inspection tools. For instance, for piping systems at height, MISTRAS utilizes rope access technicians to aid in the inspection. These individuals are capable of performing any inspection from ropes that we perform from the ground including Guided Wave, Erosion Corrosion scanning, PEC Tool or Pocket UT®.

A variety of potential damage mechanisms need to be considered when inspecting piping, such as:

  • External Erosion Corrosion
  • Internal Erosion Corrosion
  • Cracking
  • Mechanical Damage
  • Metallurgical Issues
  • Weld Quality
  • Leaking Valves
Advanced techniques used to determine the above damage mechanisms are:
Automated Ultrasonic LSI
Our LSI system performs ultrasonic surveys at 25 inches per second, allowing us to inspect large areas of piping very quickly. Our UTIA software allows the operator enhanced flexibility to analyze the data for optimum visual correlation with the A-B and C-Scans. Stitching multiple scans together allows an overview of the entire piping system.

Phased Array
Phased array is a versatile tool that electronically produces multiple wave modes and angles electronically in nanoseconds. This is an excellent choice for detecting cracking caused by a host of other damage mechanisms and is highly beneficial in providing accurate sizing data for use in Fitness for Service calculations. Phased Array may also be used to perform final acceptance of code quality welding per ASME code requirement in lieu of radiography. This application results in substantial savings to the owners by eliminating the restricted areas required when performing radiography.

Guided Wave Ultrasonics (GUL)
Guided wave technology utilizes torsional and longitudinal waves to inspect large sections of piping from one location. Guided wave is used as a screening tool, in most cases, on insulated piping as well as buried piping, wharf and jetty piping, offshore piping in splash zones and in traditionally inaccessible areas. It is also used as part of a PMI Retrofit program to locate piping welds between attachments.

Guided wave can detect both internal and external corrosion or other significant defects and locate them along the pipe. MISTRAS uses the latest guided wave technology called the G3 or the third generation system which supplies better accuracy than previous technology. In addition, Permanently Installed Sensors (PIMS) can be installed in various locations, including buried piping applications, to monitor areas that are suspect without having to dig trenches for subsequent inspections.
Ultrasonic P-Scan
Whether looking for a more thorough tool to evaluate the quality of a weld, or for environmentally assisted cracking such as fatigue, stress corrosion cracking and others, the P-Scan system is more than capable of imaging these flaws in a way to better evaluate, characterize and size them.

Computed RT
Computed Radiography is especially effective when used with profile radiographic techniques when looking for quantitative & qualitative data for piping. This technique enables evaluation of large sections of piping to determine erosion/corrosion rates in this section vs. the relatively small areas obtained using point to point ultrasonic thickness exams. In addition, computed radiography may be used during ASME or other code welding processes in lieu of traditional radiography. The combination of computed radiography and a Selenium 65 radiographic source enables a dramatic reduction of radiation in boundary areas. This reduction allows welders to work in close proximity to the inspection area.
Acoustic Emission (AE)
Leaking valves are a common problem with results showing that 5 to 10 percent of the valves in Oil and Gas plants leak. More importantly, it was determined that just 1 to 2 percent of the valves accounted for approximately 70 percent of the losses. Valve leak detection works by detecting the "noise" produced as the medium passes through the valve as "turbulent" flow. Turbulent flow creates a signal with frequency components well over 100 KHz. This allows the use of high frequency acoustic emission sensors with frequencies above the vibration and background noise level of the plant. This characteristic makes reliable detection and quantification of leaks possible. In addition to being able to determine if a valve is leaking, our proprietary algorithms allow us to "quantify" the amount of the leak.
Advanced Ultrasonic Backscatter Technique (AUBT)
Certain low alloy carbon steel material operating at temperatures and hydrogen partial pressures above the Nelson Curve, can be suspect to decarburization as well as microfissuring and macrocracking, which can result in catastrophic consequences. With the use of proven ultrasonic technologies evaluating frequency dependence, velocities, and several other factors, we are able to help determine which pieces have been affected by High Temperature Hydrogen Attack (HTHA).

Pulsed Eddy Current (PEC)
PEC technology is an inspection technique for measuring the thickness of steel objects without direct contact to the steel surface. The electromagnetic test uses a pancake probe to identify general corrosion through insulation or concrete surfaces by introducing an electric current into the transmitter coil, magnetizing the steel and measuring wall thickness. PEC is ideal for surveying large sections of piping or pressure vessels to detect areas that have been affected by moisture trapped under insulation causing corrosion of the asset being inspected. Use PEC when other NDT techniques may be limited due to the larger diameters encountered when inspecting insulated vessels.

Touch Point Corrosion
  • Increase probability of detection utilizing comprehensive global inspection methods
  • Apply appropriate ultrasonic techniques to various cracking mechanisms
  • Perform online monitoring to ensure safe operation of at-risk piping
Valve Testing and Monitoring
  • Save millions of dollars in lost production cost
  • Qualitative and quantitative measurement capabilities
Heroes Wanted: At MISTRAS, we protect critical assets. Sound familiar? Current openings include: Technicians, Engineers, Programmers, Inspectors. Make our mission your next. Read more...
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