Overview of API RP 941 - Steels for Hydrogen Service at Elevated Temperatures and Pressures
API RP 941, Steels for Hydrogen Service at Elevated Temperatures and Pressures in Petroleum Refineries and Petrochemical Plants, Eighth Edition, is a recommended practice developed and published by the American Petroleum Institute (API). This RP is intended to help identify and manage equipment potentially subject to high temperature hydrogen attack (HTHA) by putting into place practical operating limits for carbon and low alloy steels in hydrogen service at elevated temperatures and pressures. This RP also discusses how the resistance of steels to hydrogen damage can be affected by high stress, heat treating, chemical composition, and cladding. A summary of inspection methods to evaluate equipment for the presence of HTHA is also included. The first edition of the recommended practice was originally published in January 1997, and the most recent release is the eighth edition, published in February 2016.
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March/April 2020 Inspectioneering JournalBy Gerrit Buchheim, P.E. at Becht, Dave Dewees, P.E. at Becht, Charles Becht V, P.E. at Becht, and Jeremy Staats, P.E. at Becht
Nelson curves, which are the foundation of the industry’s HTHA programs, can be tied to mechanistic models from several sources, allowing the recreation of Nelson curves for different operational histories and time durations.
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BlogDecember 26, 2019 By John Reynolds at Intertek
A summary of some of the important topics that were discussed at the API Fall Refining and Equipment Standards Meeting in Atlanta.
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Reynolds Wrap Up: Highlights from the API Subcommittee on Inspection and Mechanical Integrity (SCIMI) Meetings at the Spring 2019 API Standards MeetingBlogJune 27, 2019 By John Reynolds at Intertek
A summary of some of the important topics that were discussed at the Spring Meeting, including the recently-held API Inspection and Mechanical Integrity Summit, subcommittee activities, and progress with the API Individual Certification Program.
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Reynolds Wrap Up: Highlights from the API Subcommittee on Inspection and Mechanical Integrity (SCIMI) Meetings at the Fall 2018 API Standards MeetingBlogDecember 27, 2018 By John Reynolds at Intertek
A quick summary of some of the important topics that were discussed at the Fall Meeting, including the upcoming API Inspection and Mechanical Integrity Summit, subcommittee activities, and progress with the API Individual Certification Program.
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September/October 2018 Inspectioneering JournalBy Michael Nugent at AEIS, LLC, and Timothy Armitt at LINDT, UK
This article discusses the advances in NDE that have given owners increased confidence on how to assess equipment integrity in HTHA service providing risk prioritization of equipment as well as providing the ability to make more reliable...
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A New Method for Prioritizing Equipment in HTHA Service for Inspection & Replacement and the Challenges in Obtaining Process Conditions to be Used in the HTHA AssessmentNovember/December 2014 Inspectioneering JournalBy Gerrit Buchheim, P.E. at Becht
This article provides background on HTHA, discusses some current developments in HTHA inspection and mitigation, and describes how one refiner is instituting an HTHA risk management plan for its refineries along with challenges they have encountered.
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BlogJanuary 20, 2014 By Jeremiah Wooten at Inspectioneering, LLC.
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.
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November/December 2010 Inspectioneering JournalBy John Reynolds at Intertek
High Temperature Hydrogen Attack (HTHA) is a long known and still occurring degradation issue for fixed equipment construction materials in the hydrocarbon process industry where hydroprocess plants (hydrogen plus hydrocarbons) are in service....
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HTHA falls into multiple categories of corrosion mechanisms, including environmentally assisted cracking, hydrogen assisted cracking, and high temperature degradation. Sometimes HTHA is confused with low temperature hydrogen cracking mechanisms...
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