While similar to dry air, nitrogen purging keeps the environment oxygen-free, preventing the formation of polythionic acids from sulfide compounds. 4. Key Takeaways from the Latest Standards
A quick Google search for "NACE SP0170 PDF free download" often yields results that are outdated or unauthorized. Industry experts warn that using an unverified copy of the standard is a dangerous gamble. nace sp0170 pdf 2021
: The full designation is AMPP SP0170-2021 (Revised 2021-12-10). While similar to dry air, nitrogen purging keeps
) form rapidly when metal sulfide corrosion scales—deposited on internal surfaces during regular operation—are simultaneously exposed to moisture ( ) and oxygen ( ) during a shutdown. Internal vs. External Environments Industry experts warn that using an unverified copy
Often applied as an internal wash or spray to all surfaces, including piping, reactors, and exchangers.
The standard, titled "Protection of Austenitic Stainless Steels and Other Austenitic Alloys from Polythionic Acid Stress Corrosion Cracking During a Shutdown of Refinery Equipment," is a critical standard practice used by the petroleum refining industry. While users often search for a "2021" edition, it is important to note that as of May 2026, the NACE SP0170-2018 edition remains the most current and active version of the standard. In 2021, NACE International merged with the Society for Protective Coatings (SSPC) to form AMPP (Association for Materials Protection and Performance), which now maintains the standard under Task Group 173. Overview of NACE SP0170