The standard applies to fixed refinery equipment such as:
Effectiveness Metrics: The standard provides metrics for ECDA program performance: detection probability, false-negative rate, excavation hit-rate (ratio of excavations confirming corrosion), and mitigation follow-through. It encourages continuous improvement via feedback loops between verification results and modeling.
Spraying surfaces with a neutralizing solution (like soda ash) to "kill" any acid the moment it touches the metal.
If you can tell me if you are looking for this for a , an active shutdown , or internal training , I can help you find more specific implementation advice.
For new equipment designs, NACE SP0170 recommends evaluating chemically stabilized grades like 321 or 347 stainless steel, which resist sensitization during high-temperature operations. nace sp0170 pdf 2021
: The full designation is AMPP SP0170-2021 (Revised 2021-12-10).
: The 2021 context of this story involves sophisticated "shields." The standard outlines three primary defenses: Soda-Ash Wash : Neutralizing the acid before it can bite.
Obtaining the official PDF from ensures that the engineering team has the correct data sets, charts, and legal disclaimers necessary for audit trails and insurance compliance.
) typically keeps standards in effect for several years; the 2018 version remains the active guidance for preventing Polythionic Acid (PTA) Stress Corrosion Cracking (SCC) during refinery shutdowns. ANSI Webstore Core Content & Mitigation Methods The standard applies to fixed refinery equipment such
| Standard | Title | Focus Area | Primary Concern | | :--- | :--- | :--- | :--- | | | Protection of Austenitic Stainless Steels... from Polythionic Acid SCC | Refinery shutdowns | Polythionic acid (PTA) cracking in sensitized austenitic alloys | | NACE MR0175 / ISO 15156 | Materials for use in H₂S-containing Environments in Oil and Gas Production | Upstream (oil & gas production) | Sulfide stress cracking (SSC) from H₂S exposure | | NACE MR0103 / ISO 17945 | Materials Resistant to SSC in Corrosive Refinery Environments | Downstream (refining, petrochemicals) | Sulfide stress cracking (SSC) in H₂S service, different material limits | | NACE SP0169 | Control of External Corrosion on Underground or Submerged Metallic Piping Systems | External corrosion control | Cathodic protection (CP) criteria (e.g., -850mV or 100mV polarization) |
| Parameter | Requirement (2021) | |-----------|--------------------| | | ≥ 99.5% Zn (per ASTM B833) | | Thickness (typical) | 250–500 µm (10–20 mils) | | Bond strength | ≥ 1.5 MPa (pull-off test) | | Porosity | ≤ 5% (image analysis or ferroxyl test) | | Electrical continuity | < 2 ohms between segments | | Current density | 5–20 mA/m² of anode surface |
Here’s a useful, actionable piece of content about — structured for engineers, inspectors, and asset integrity professionals who need a quick yet thorough reference.
NACE SP0170-2018 remains the active standard for protecting austenitic stainless steels from polythionic acid stress corrosion cracking (PTA SCC) during refinery shutdowns as of 2021, focusing on nitrogen purging and alkaline washing to mitigate risks. The standard, now managed by AMPP, outlines critical procedures for preventing corrosion in sensitized austenitic alloys common in hydrotreating and cracking units. Access the standard through the ANSI Webstore . If you can tell me if you are
SP0170 integrates corrosion science and probabilistic risk assessment. Important technical aspects include:
Formerly known as , SP0170-2021 is the industry standard for “Protection of Steel in Concrete from Corrosion Using Thermal-Sprayed Zinc Anodes” . It provides guidelines for designing, applying, and maintaining zinc-based thermal spray coatings (metallizing) as a galvanic cathodic protection (CP) system for reinforced concrete structures.
NACE SP0170 provides several proactive approaches to prevent PTA SCC. The two main techniques are: 1. Dry Air Purging (Nitrogen Purging)