NACE SP0170: Protection of Austenitic Stainless Steel from Pitting and Crevice Corrosion
Standard for corrosion protection of stainless steels impacting material selection and inspection requirements.
NACE International (now part of AMPP) writes the corrosion, coatings, and sour-service standards that determine inspection scope for hydrogen-cracking-prone equipment.
NACE MR0175 / ISO 15156 is invoked by every sour-service procurement specification in the upstream and refining markets.
NACE SP0170 is invoked when the scope of work matches its title — protection of austenitic stainless steel from pitting and crevice corrosion — and when the contract or regulatory regime cites it as the controlling document. In power and nuclear work, the inspection plan is built directly off the standard's tables; an auditor will cite the paragraph that was followed (or the one that was missed) when writing a finding. On petroleum and petrochemical equipment, NACE SP0170 usually feeds into a written mechanical-integrity program: inspection intervals, examination methods, and acceptance criteria are all traced back to a clause number in the document.
Methods covered
Industries
- Oil & Gas
- Petrochemical
- Power Generation
- Personnel qualification: examinations under NACE SP0170 must be performed by inspectors qualified and certified to a recognised scheme (typically ASNT SNT-TC-1A, CP-189, or ISO 9712 depending on jurisdiction), with documented training hours, vision tests, and a controlling written practice.
- Written procedure: every examination requires a written, controlled procedure that names the method, equipment, calibration steps, scanning pattern, and acceptance criteria — and is qualified before first use.
- Equipment verification: ultrasonic instruments must be verified against a calibration block (V1, V2, IIW, or job-specific reference) at intervals defined by the procedure — typically before use, every four hours of scanning, on operator change, and at end of shift.
- Acceptance criteria: indications are evaluated against the standard's tabulated limits (length, depth, alignment, frequency); any indication exceeding the criteria is recorded, dispositioned, and either repaired or evaluated for fitness-for-service.
- Documentation: examination reports must include enough information for a third party to reproduce the inspection — equipment serial numbers, calibration records, inspector ID, sketches of indications, and the controlling procedure revision.
NACE SP0170 is maintained on its publishing organisation's revision cycle. The version cited in any contract or written inspection program should be tracked so that revisions can be reviewed against the existing inspection plan and any clause changes worked into the next procedure update.
A typical refinery turnaround applies NACE SP0170 to the inspection scope for high-temperature piping and pressure vessels: corrosion-monitoring locations are read with UT thickness gauges, girth welds on repaired sections are radiographed or PAUT-scanned, and any indication outside the standard's acceptance table is dispositioned through API 579 fitness-for-service before the unit restarts.
What does NACE SP0170 cover?
NACE SP0170 (Protection of Austenitic Stainless Steel from Pitting and Crevice Corrosion) is published by NACE International. Standard for corrosion protection of stainless steels impacting material selection and inspection requirements..
Is NACE SP0170 mandatory or voluntary?
NACE SP0170 is a consensus standard. It becomes mandatory when invoked by a contract, by another code that cites it (for example ASME Section V calling out an ASTM practice), or by a regulator that has adopted it into law in a specific jurisdiction.
Who is qualified to perform inspections under NACE SP0170?
Inspections under NACE SP0170 must be performed by personnel qualified and certified to a recognised NDT certification scheme — most commonly ASNT SNT-TC-1A or CP-189 in the United States, ISO 9712 in much of the rest of the world, and NAS 410 for aerospace work. The written practice that controls qualification must be in place before any examination is started.
Which other standards are commonly cited alongside NACE SP0170?
NACE SP0170 is most often cited together with the parent code that brings it into the contract — typically ASME Section V or VIII for U.S. pressure equipment, AWS D1.1 for structural welding, API 510/570/653 for in-service petroleum equipment, or the matching EN/ISO standard for European and international work.
Standard Code
NACE SP0170
Organization
NACE International
Methods Covered
2 method(s)
Industries
3 sector(s)
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