Keep Your Cool with High Temperature Hydrogen Attack (HTHA) Cracking Assessments

Priscilla Johnson

Content Marketing Lead

What do you get when you combine carbon steel, hydrogen, temperatures over 205° C (400° F) and pressure? The perfect conditions to manifest methane resulting in High Temperature Hydrogen Attack (HTHA). Who cares? Your pressure vessel or piping trying to keep its contents to itself.

We all remember the 2010 refinery disaster in Washington. We don’t need another devastating incident to be reminded of the risks of hydrogen damage. The proactive detection of HTHA helps ensure plant and worker safety as well as efficient operations across the energy sector.

The early stages of HTHA present a challenge for inspectors using conventional ultrasonic testing (UT) methods, as methane-related indications are typically much smaller than the ultrasonic wavelengths employed. It’s difficult to discriminate HTHA from unusual grain size, inclusion, surface variations or geometry; a number of anomalies can often lead to false positive results of an attack.

Advances in ultrasonic techniques has enabled technicians to characterize HTHA with leading portable units. You need to feel confident in your inspection data, and that’s why Eddyfi Technologies presents the M2M Gekko® as the trusted flaw detector capable of phased array UT (PAUT), Time of Flight Diffraction (TOFD), TULA (TOFD Ultra Low Angle), and Total Focusing Method (TFM) in one user-friendly instrument with intuitive software for quick setup and shorter inspection assessments.

With multiple techniques available from the field proven Gekko and pioneer of real-time TFM, early detection of bubbles forming to produce micro-fissures at steel grain borders is now possible, and preventative measures can be recommended.

So, how exactly does Eddyfi Technologies’ portable PAUT unit detect HTHA, the defect with a reputation for being almost imperceptible?

TOFD is not only very sensitive to small discontinuities, it is also quite fast. Gekko enables concurrent PAUT with TOFD for a single assessment of welding defects and through-wall sizing. With TULA probes, examination of denser materials is also achievable. Because inspectors are evaluating heat exchangers, vessels, tanks and pipelines with varying wall thicknesses, the Gekko supports many purpose-built probes to ensure maximum productivity. Clusters and short indications in A-Scan signals provide an initial warning for HTHA.

The advantage of PAUT paired with TOFD is further complemented with the additional use of TFM for the most comprehensive hydrogen damage assessment possible. The Gekko contains a complete toolbox for TFM including Time Corrected Gain (TCG) calibration, and high-resolution TFM imaging with up to 128 elements. Inspectors can benefit from live interpretation of TFM frames and make assessments that ultimately help improve operations and reduce human and environmental risk by monitoring HTHA damage.

Every day spent not really knowing the structural integrity of plant equipment and critical components is a liability that nobody can afford. And now, nobody has to. All levels of NDT technicians can take advantage of the state-of-the-art technology offered by Gekko with Capture software and easily detect the presence of high temperature hydrogen attack well in advance, or just in time – so you can keep your cool. Contact us to learn more about Eddyfi Technologies’ advanced non-destructive testing solutions for the repeatable, actionable, meaningful and preventive data results you should expect to stay Beyond Current.