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.
Formerly known as RP0170, the full title of this standard is: “Protection of Austenitic Stainless Steels and Other Austenitic Alloys from Polythionic Acid Stress Corrosion Cracking During Shutdown of Refinery Equipment.”
: Neutralizes any formed acids using a soda-ash (sodium carbonate) solution. Dry Nitrogen Purging nace sp0170 pdf
Her proposal was met with skepticism at first. "Standards exist to keep us consistent," said the maintenance manager. "Adding this is expensive and subjective." Maya listened and then pointed to the hairline crack's repair bill printed on her tablet. "Consistency didn't find this. The cost of not finding it was far higher."
The Significance of NACE SP0170 PDF
She scrolled to Section 6: Design of Coating Systems. 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.
Her phone buzzed. It was Dave, the night shift manager at the Gulf Coast Refinery. Check the revision date
Maya was a corrosion engineer newly moved to coastal operations and still learning to read standards the way older hands did — not only as rules but as stories about what had failed before. She read SP0170 the way one reads a map after a shipwreck: cataloguing measurement techniques, specifying coupon placements, describing stray current mitigation, listing allowable potential ranges. Each clause was precise, written for auditors and inspectors. It told her where to put probes and how to interpret millivolt shifts. It did not tell her where the leaks began.