Nace Sp0170 Pdf [new] Now

PTA can cause rapid, intergranular stress corrosion cracking in sensitized austenitic stainless steels.

“Dave, listen to me. You’re going to lift the pipe. Not much. Just half an inch.”

was created to define how to protect fixed equipment (like pressure vessels and heat exchangers) in petroleum refineries. nace sp0170 pdf

The technical standard , officially titled "Protection of Austenitic Stainless Steels and Other Austenitic Alloys from Polythionic Acid Stress Corrosion Cracking During a Shutdown of Refinery Equipment," is a foundational document for asset integrity in the petroleum refining industry. Maintained by the Association for Materials Protection and Performance (AMPP) , this standard maps out exact operational workflows to shield critical components from devastating, rapid structural failures during planned downtimes.

NACE SP0170 provides critical guidelines for protecting austenitic stainless steels and alloys from polythionic acid stress corrosion cracking (PTA SCC) during refinery equipment shutdowns, focusing on preventing material degradation. Mitigation strategies, including dry nitrogen purging and alkaline washing, neutralize sulfide corrosion products to maintain equipment integrity. For more details, visit ANSI Webstore . PTA can cause rapid, intergranular stress corrosion cracking

The standard requires adding an inhibitor (such as 0.5% sodium nitrate, NaNO₃) to the solution to prevent chloride stress corrosion cracking (Cl-SCC), as potable water often contains trace chlorides.

During circulation of the alkaline wash, the pH of the effluent must be regularly checked. It must remain highly basic (pH > 9). If the pH drops, it indicates that acids are actively neutralizing the solution, and more soda ash must be added. Not much

If you are planning an upcoming refinery turnaround or need to draft a formal facility procedure, tell me:

She scrolled to . The standard was famous for buried pipelines—how to wrap them, how to test for holidays (microscopic pinholes in the coating). But buried pipes weren’t her concern. It was the support saddle .

Polythionic Acid Stress Corrosion Cracking is an aggressive form of localized corrosion that targets sensitized austenitic stainless steels (such as Types 304, 304H, 316, and 321) and specific nickel-chromium-iron alloys. The Chemistry Behind the Attack During regular refinery operations, hydrogen sulfide ( H2Scap H sub 2 cap S