Inspectioneering
Blog

Some Resources to Learn More about Preventing High Temperature Hydrogen Attack (HTHA)

By Jeremiah Wooten at Inspectioneering, LLC.. January 20, 2014

Last week we mentioned three important tips to consider when addressing high temperature hydrogen attack (HTHA). This week, we'd like to provide the reader with a few helpful resources that deal with the topic of HTHA.

What is High Temperature Hydrogen Attack?

High Temperature Hydrogen Attack is a potentially dangerous damage mechanism that can occur in process equipment that is exposed to hydrogen at elevated temperatures over time and under dry conditions, when hydrogen disassociates into nascent (atomic) hydrogen and is then driven into the steel by the temperature and pressure of the environment. That atomic hydrogen then reacts with unstable carbides in the steel to form methane gas, which then causes gas pockets to form and leads to material degradation.

In 2010, HTHA was to blame for a tragic incident at a Washington, USA refinery when the shell of a feed-effluent heat exchanger in a naphtha hydrotreating (NHT) unit ruptured, ultimately resulting in seven fatalities. Since this incident, the subject of HTHA and inspection for HTHA has been extensively discussed at well-attended meetings on the topic at NACE, API, and AFPM events, indicative of the high level of attention it has received as operators continue to struggle to understand and detect this insidious damage mechanism. Joint Industry HTHA projects have commenced and new examples of HTHA have been submitted to the API Recommended Practice (RP) 941 committee for consideration for inclusion of these new experiences in future updates of the standard.

HTHA Resources

If you are looking for more information about HTHA, there are a number of great resources available. 

  • The Inspectioneering LinkedIn Group is a resource for industry professionals to discuss asset integrity topics including HTHA. Group membership is free.
  • Inspectioneering's HTHA topic page contains hyperlinks to HTHA-related articles that have been published in Inspectioneering Journal and on Inspectioneering.com.
  • API RP 941 establishes practical operating limits for carbon and low alloy steels in hydrogen service at elevated temperatures and pressures.

Feel free to leave comments using the form below. Let us know where you go to learn about HTHA, damage mechanisms, and anything and everything related to corrosion and materials.


Comments and Discussion

There are no comments yet.

Add a Comment

Please log in or register to participate in comments and discussions.

Interested in equipment reliability & integrity? Sign up for weekly updates.

Inspectioneering Journal

Explore over 20 years of articles written by our team of subject matter experts.

Company Directory

Find relevant products, services, and technologies.

Job Postings

Discover job opportunities that match your skillset.

Case Studies

Learn from the experience of others in the industry.

Event Calendar

Find upcoming conferences, training sessions, online events, and more.

Industry News

Stay up-to-date with the latest inspection and asset integrity management news.

Blog

Read short articles and insights authored by industry experts.

Acronyms

Commonly used asset integrity management and inspection acronyms.

Asset Intelligence Reports

Download brief primers on various asset integrity management topics.

Videos

Watch educational and informative videos directly related to your profession.

Expert Interviews

Inspectioneering's archive of interviews with industry subject matter experts.