Leave the alkaline film on the metal surfaces; do not rinse it off with fresh water before exposing the asset to air. Summary of Best Practices
This public link is valid for 7 days and shares a thread, including any personal information you added. This link or copies made by others cannot be deleted. If you share with third parties, their policies apply. Can’t copy the link right now. Try again later.
If you'd like a real summary or key takeaways from NACE SP0170 (now often called ), let me know—I can explain what it covers and why it matters in plain language. nace sp0170 pdf
NACE SP0170 PDF: Protecting Refinery Equipment from Polythionic Acid Stress Corrosion Cracking
The standard is a critical technical document for the petroleum refining industry, focusing on protecting equipment from Polythionic Acid Stress Corrosion Cracking (PTA SCC) during refinery shutdowns. Leave the alkaline film on the metal surfaces;
The (now managed by AMPP ) 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 copyrighted document and is not legally available as a free "complete piece" PDF.
Sensitization occurs in the heat-affected zone (HAZ) of welds. Ensure your NDE team knows where to look for cracking – typically adjacent to welds in the HAZ. If you share with third parties, their policies apply
Do not assume "soda ash" is generic. Verify the concentration of sodium carbonate solution (typically 2-5% by weight) using titration or conductivity.
). NACE SP0170 outlines the exact chemical and operational safeguards required to shield sensitized alloys from this acid network.
Alkaline washing is a widely used, effective method for neutralizing acids that have already formed or preventing their formation, as noted in the NACE SP0170 technical guide.