The official source for all NACE standards.
Disclaimer: This article is for informational purposes only. Always consult the official NACE/AMPP standard for specific engineering requirements.
Existing metal sulfides deposited inside the equipment during operation. Moisture ( H2Ocap H sub 2 cap O nace sp0170 pdf 2021
A quick Google search for "NACE SP0170 PDF free download" often yields results that are outdated or unauthorized.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.
(Standard Practice), maintained under the joint AMPP (Association for Materials Protection and Performance) banner, outlines the industry-accepted protocols for shielding critical equipment from localized environmental cracking during shutdowns. The official source for all NACE standards
: Preventing the formation of liquid water by maintaining a dry air environment.
While you may see "2021" associated with this standard in search results, remains the current, active version. It was discussed heavily in 2021 at the AMPP CORROSION conference , where engineers shared new data on how different alloys—like those with higher Chromium and Nickel—handle these harsh shutdown environments. the NACE SP0170-2018 standard
The relative humidity (RH) inside the vessel must be maintained at low levels (typically under 20% RH ). By keeping the environment completely dry, liquid water cannot condense on the metal faces, halting the chemical reaction required to generate polythionic acid. Industry Application and Implementation Matrix
The standard NACE SP0170 (now managed by ) provides critical guidelines for protecting austenitic stainless steels and other austenitic alloys from Polythionic Acid Stress Corrosion Cracking (PTA SCC)
. If you are operating with austenitic stainless steels, the NACE SP0170-2018 standard