What Are the API Core Certifications?
The three core API Inspector Certifications are:
- API 510 – Pressure Vessel Inspector
- API 570 – Piping Inspector
- API 653 – Aboveground Storage Tank Inspector
These certifications form the foundation of the API Individual Certification Program (ICP) for in-service inspection professionals. Because they share many common reference documents and inspection principles, they are often pursued together by inspectors looking to broaden their qualifications and career opportunities.
Common Reference Documents
All three certifications share several key reference publications, including:
- API RP 571 – Damage Mechanisms Affecting Fixed Equipment
- API RP 576 – Inspection of Pressure-Relieving Devices
- API RP 577 – Welding Inspection and Metallurgy
- API RP 578 – Material Verification Program
- ASME Section V – Nondestructive Examination
- ASME Section IX – Welding, Brazing, and Fusing Qualifications
As a result, a significant portion of the study material is common across the three examinations.
API 510 vs. API 570
API 510 and API 570 both deal with the inspection of pressurized equipment:
- API 510 focuses on pressure vessels constructed to ASME Section VIII.
- API 570 focuses on process piping designed to ASME B31.3.
Although they are based on different construction codes, the two certifications share many engineering principles, inspection techniques, calculations, and code requirements. For example, both use similar methods for determining inspection intervals, including the corrosion-rate (half-life) approach, where the next inspection is scheduled after approximately half of the available corrosion allowance has been consumed.
Examination Overlap
Approximately 30% of the examination content for the three core certifications is based on the common API Recommended Practices and ASME reference documents listed above. This overlap allows candidates to build on knowledge gained from one certification when preparing for another.
For this reason, many inspectors aim to obtain all three core certifications. After successfully passing one examination, candidates have already mastered a substantial portion of the material required for the other two, making subsequent certifications easier, faster, and more cost-effective to achieve.
