As part of the Ipog (Inspection by Guided Waves) project of the 2020 GRTgaz Internal Innovation Challenge, Mistras won the title of co-winner alongside the nine other files selected out of the 175 submitted, following a Guided Waves mission that took place on the GRTgaz station in Cuvilly (60), in September 2019.
Set up by GRTgaz several years ago, this challenge allows the company to detect innovative solutions responding to unresolved problems encountered internally, with real financial and /or security challenges.
GRTgaz was looking for a non-intrusive and effective piping inspection solution for wall passage control without having to open it. Mistras was able to convince the management of the GRTgaz innovation, thanks to its Guided Waves solutions: the GWT (Guided Waves Testing) method, which uses GUL technology as well as the GBW (Guided Bulk Wave) method, also known as HOMC (Higher Order Mode Cluster).
These two advanced NDT methods respond to the same problem: the non-intrusive inspection of hard-to-reach or even "inaccessible" areas from a single position.
While the GWT method allows the control of long distances, the GBW/HOMC method uses short-range guided waves for medium-distance control (up to 1 meter).
In some cases, these two methods are complementary: this was the case during the inspection at GRTgaz, where GBW was used for the control of the floor-wall interface and GWT for the inspection of the rest of the wall.
Following the GWT control, additional investigations other than GBW can also be carried out using other methods such as the Touch Point Corrosion (TPC) method, developed by Mistras to characterize the presence of corrosion under support.
Focus on the GWT solution
- Rapid monitoring of pipeline integrity (screening) over long distances
- Limits the removal of heat insulation and cooling
- Limits the number of scaffoldings
- Ideal solution for road crossings and non-scrapable pipes
- Solution for "inaccessible" areas: passages in scabbards, gutters, merlons, ground entrances, wall crossings...
- Prioritizes and targets additional NDT and inspections

