API 570-2016 Piping Inspection Code: In-service Inspection, Rating, Repair, and Alteration of Piping Systems

Scope of API 570-2016

API 570-2016, “Piping Inspection Code: In-service Inspection, Rating, Repair, and Alteration of Piping Systems,” establishes the minimum requirements for the inspection, rating, repair, alteration, and re-rating of in-service piping systems. This code primarily covers piping systems in hydrocarbon and chemical process services, but may also be applied to other services where the owner-user deems appropriate.

The standard applies to metallic and nonmetallic piping systems that have been placed in service, including their components such as valves, fittings, flanges, and supports. It provides guidelines for both pressure and nonpressure piping, though certain limitations exist:

• Piping with nominal diameter less than NPS 1/2 (DN 15) is excluded.
• Piping systems subject to specific failure modes such as creep or fatigue may require additional assessment.

API 570-2016 references numerous other standards, including ASME B31.3 for design and construction, ASME Section IX for welding qualifications, and API 571 for damage mechanisms.

Key Technical Requirements of API 570-2016

Owner-User Responsibilities

The owner-user is ultimately responsible for the safe operation of piping systems and must develop a written inspection plan that includes:

• Identification of all piping systems covered.
• Damage mechanism assessment per API 571.
• Inspection intervals and methods.
• Qualified inspection personnel.
• Repair and alteration procedures.

Inspector Certification

API 570-2016 requires that piping inspectors be certified in accordance with the API 570 examination program or equivalent, meeting experience and education requirements. The code also stipulates ongoing training and recertification.

Inspection Intervals

The standard defines intervals based on remaining life calculation using corrosion rates derived from thickness measurements. Table 1 below outlines the typical intervals as defined in API 570.

Repair and Alteration

Any repair or alteration must be carried out using qualified procedures and personnel. The code requires that the original design conditions are maintained or recalculated. Alterations such as addition of branches, replacement of piping sections, or changes in material require re-rating and must comply with ASME B31.3.

Implementation Highlights

Successful implementation of API 570-2016 involves integrating the code into the overall plant inspection management system. Key steps include:

• Developing a corrosion control document (CCD) or similar.
• Conducting damage mechanism reviews.
• Establishing thickness measurement locations (TMLs) and monitoring data.
• Performing risk-based inspections where justified.
• Maintaining accurate records of inspection findings.

Compliance Notes for Auditors and Engineers

Third-Party Inspection

While API 570 does not mandate third-party inspection, many owner-users engage authorized inspection agencies (AIAs) to verify compliance, especially for jurisdiction required inspections.

Documentation Requirements

The code requires comprehensive documentation of inspection reports, repair procedures, and alteration records. Records must be retained for the life of the piping system.

Jurisdictional Interfaces

API 570-2016 is recognized by many local and national authorities. However, engineers must verify any jurisdictional requirements that may exceed the code.

Frequently Asked Questions

Document reference: API 570-2016. Technical article written for 2026 compliance review.