High Temperature Hydrogen Attack (HTHA) is a condition that
can occur in process equipment exposed to hydrogen at elevated temperatures and
pressures over time. Hydrogen reacts
with carbides in steel and can manifest into internal decarburization and
fissuring including molecular hydrogen and methane accumulating at grain
boundaries. Subsequent high localized
stresses can lead to formation of fissures or cracking in steel, resulting in
degradation of mechanical properties. HTHA poses a substantial threat of
catastrophic failure if left undetected. The main factors influencing HTHA are
hydrogen partial pressure, temperature, the duration of the exposure, and
Carbon and low alloy steels are the most susceptible to HTHA
but any process piping and vessels with the above combination are at risk.
Acuren’s HTHA Arsenal
Throughout the industry, conventional methodologies have not
proven effective at detecting early stage HTHA. Acuren has recognized this limitation, and has
adopted a suite of advanced NDE screening methodologies that employ the latest
in advanced ultrasonic equipment and techniques to accurately diagnose symptoms
64 Element PAUT
– High Resolution Phased Array
Sound is generated across the active elements when a voltage is applied, with increased firing power/elements, a greater resolution is achieved
Greater resolution means the ability to see smaller indications that may not be detected using conventional ultrasonic methods and the ability to discriminate between single or clusters of smaller indications
TOFD – Time of
Diffraction-based method that measures the reflection of the indication body and diffraction of the sound wave at the indication tips making it a highly sensitive sizing technique
A reliable screening tool for the early stages of HTHA
Wide coverage area and useful for weld and parent material examinations
Small data files
Equipment is readily available and cost effective
Needs to be performed in conjunction with other NDE methods to verify exact position and indication type
TULA – TOFD Ultra
Simple but highly sensitive means of detecting HTHA
Scan speeds exceed Phased Array and TFM
Probes with different specific focal depths
Can be used in-lieu of TOFD where there is only room for one probe
Operator training is essential
TFM – Total
Similar to PAUT, except one element fires and all elements listen for reflections
Detects defects in many different orientations
Good sensitivity to even small defects
Very large data files
Slower method than TOFD and TULA
Because HTHA inspections aren’t regulated, Acuren’s combination of engineers, specialists and rope access experts can help take the guesswork out of your approach, assist you with designing a program that fits your specific equipment, and minimize your risk profile
Our in-house engineers can utilize the findings of the
advanced NDE technologies in conjunction with Fit For Service (FFS) API 579
engineering evaluations to determine the best course of action for your assets.
If early stage HTHA is suspected, the FFS can quickly resolve if the asset can
continue to run, or determine correct inspection methods and intervals for
mitigation of risk.
ACUREN HASMORE QUALIFIED HTHA INSPECTION TECHNICIANS IN CANADA AND THE USA THAN ANY OTHER NDE PROVIDER
The evaluation of HTHA damage is highly specialized and
requires advanced HTHA training which may include 3rd party training
or performance demonstration qualification examination recognized by
owner/users. Acuren has more qualified
HTHA inspection technicians in Canada and the US than any other NDE provider, a
number of whom also hold rope access qualifications. We have the resources
(personnel & equipment) to support customers across North America.
Contact us today to help you assess your risk, and design an approach to address your specific areas of concern at firstname.lastname@example.org or 1-800-218-7450.
Acuren provides integrated services including inspection, repair and maintenance via rope acess using composite crews with multi-disciplined trades, experienced personnel, IRATA certified technicians, and customized access optimization programs.
Acuren has a specialized team with aerospace industry experience that use both traditional and advanced nondestructive testing methods to identify defects in critical structural, airframe, and engine and accessory components.
Acuren’s engineering, inspection and industrial services teams consist of engineers, technologists and tradespeople with a diverse educational background, working in the mining industry for over 40 years.
We are familiar with the unique codes and regulations of the rail industry, including DOT in the US and Transport Canada, and we're constantly innovating to create enhanced testing procedures that ensure optimum quality and safety.