1.2 Inspector Roles, Responsibilities & Certification Requirements

The API 653 Authorized Inspector: Definition and Authority

In the API 653 Section 3 definitions, an Authorized Inspector is defined as an individual who has satisfied the certification requirements established by the API Individual Certification Program (ICP). The Authorized Inspector acts as the technical arbiter of tank mechanical integrity, executing on-site visual assessments, directing non-destructive examinations, calculating corrosion rates, and verifying that all repairs, alterations, and reconstruction projects conform strictly to API 653 and owner-user specifications.

Non-Delegable Authority vs. NDE Examiners

A critical distinction exists between an Authorized Inspector and an NDE Examiner:

• Authorized Inspector (AI): Must be certified under API 653. The AI holds sole statutory and code responsibility for reviewing inspection records, performing external and internal visual inspections, determining minimum acceptable thicknesses ($t_{min}$), approving repairs, witnessing or verifying hydrostatic testing, and certifying the final inspection report authorizing return to service. These core evaluative tasks cannot be delegated.
• NDE Examiner: An individual certified under the employer’s written practice conforming to ASNT SNT-TC-1A or CP-189 (in methods such as Ultrasonic Testing [UT], Magnetic Flux Leakage [MFL], Radiographic Testing [RT], Magnetic Particle Testing [MT], or Liquid Penetrant Testing [PT]). Examiners may collect thickness readings, scan tank floors, or radiograph weld seams, but the Authorized Inspector must review, interpret, and formally accept all NDE findings.

---

Exam Format: Two Parts, Two Different Study Strategies

The API 653 certification exam is a 170-question computer-based test, of which 140 are scored and 30 are unscored pretest items seeded for future exams. The sitting is split into two parts that test genuinely different skills, and the Body of Knowledge is explicit about why:

Three consequences for how you prepare:

• Memorize the closed-book layer deliberately. Corrosion rate, remaining life, remaining corrosion allowance, and inspection interval formulas and the rules for setting intervals may all appear closed book, so drill them until they are automatic.
• Practice navigation, not recall, for the open-book layer. Tab the tables and figures you will be sent to — API 653 Tables 4.1, 4.2, 4.3, 4.4, and 4.5; Figures 4.1, 4.2, 5.1, 5.2, 9.1 through 9.5; Annex B Figures B.1 through B.13; and the API 650 opening figures and tables. Speed of lookup is the scored skill.
• Only the listed editions count. Questions come solely from the publications in the Body of Knowledge at the editions named on the matching Publications Effectivity Sheet, and only the sections listed there are available during the open-book portion. Some jurisdictions still operate under older editions codified in state law; the exam does not.

Choose the best answer from the options provided — API notes that most ICP items are single-answer multiple choice, with alternative item types being introduced.

---

Education and Experience Qualification Pathways

To ensure candidate inspectors possess the necessary engineering foundation and hands-on competence, API 653 Annex D specifies strict eligibility criteria to sit for the computerized, 170-question ICP examination. The required years of documented experience in aboveground storage tank activities vary inversely with the candidate's formal education level:

+-------------------------------------------------------------------------+
|                    API 653 ICP QUALIFICATION PATHWAYS                   |
+---------------------------------------+---------------------------------+
| Formal Educational Credential         | Required Documented Experience  |
+---------------------------------------+---------------------------------+
| Bachelor of Science in Engineering or  | 1 Year of AST design, repair,   |
| Engineering Technology                | operation, or inspection        |
+---------------------------------------+---------------------------------+
| 2-Year Associate Degree or Technical   | 2 Years of AST design, repair,  |
| Certification in Engineering/NDT      | operation, or inspection        |
+---------------------------------------+---------------------------------+
| High School Diploma or Equivalent     | 3 Years of AST design, repair,  |
| (GED)                                 | operation, or inspection        |
+---------------------------------------+---------------------------------+
| No Formal Educational Credential      | 5 Years of documented AST       |
|                                       | design, construction, repair,   |
|                                       | operation, or inspection        |
|                                       | (>= 1 year in inspection)       |
+---------------------------------------+---------------------------------+

Documented experience must reflect direct involvement with aboveground atmospheric storage tanks in petroleum refineries, chemical processing plants, pipeline terminals, or marine shipping facilities. Two further conditions from the API ICP application rules are easy to overlook:

• The qualifying experience must have been gained within the last 10 years, while employed by or under contract with an authorized inspection agency.
• For the 2-year, 3-year, and 5-year pathways, at least one of those years must be in inspection (the remainder may be design, construction, repair, or operation).

API also recognizes technical military service as an education substitute: 3 or more years of technical military service maps to the 1-year experience pathway, and 2 years of technical military service maps to the 2-year pathway.

---

Recertification Cycle and Professional Development

Achieving initial certification is not a lifetime credential. API 653 certificates expire every three years, requiring active maintenance and continuing competency verification:

The 3-Year Recertification Term

Every three years, the certified inspector must submit a formal application demonstrating:

• Active Practice Verification: The inspector must document that at least 20% of their professional time over the preceding three-year certification term was actively spent performing, supervising, or directing API 653 storage tank inspection activities.
• Continuing Professional Development (CPD): API 510, API 570, and API 653 certificants must complete 24 CPD hours per 3-year recertification cycle, earned through continuing education, industry conference attendance, training courses, and verified inspection assignments.

The 6-Year Web Quiz Requirement

Every six years (coinciding with every second three-year renewal cycle), active practice verification alone is insufficient. The inspector must also:

• Successfully take and pass the online recertification web quiz.
• The web quiz is an open-book, timed examination of 25 questions with a 4-hour limit, administered online through API’s ICP portal. It focuses specifically on code revisions, addenda, and technical modifications published across the referenced API and ASME publications during the prior six years.
• The quiz and the recertification application open 90 days before the expiration date and remain available through a 90-day grace period after it. If an inspector fails to apply or fails the web quiz by the end of that grace period, the certification is terminated. Reinstatement requires reapplying and passing the full 170-question computerized proctored examination.

---

Organizational Roles and Division of Responsibilities

API 653 delineates an operational framework involving four primary entities: the Owner-User, the Authorized Inspection Agency, the Authorized Inspector, and the Repair Organization.

+-------------------------------------------------------------------------+
|                       API 653 GOVERNANCE HIERARCHY                      |
|                                                                         |
|                        +-----------------------+                        |
|                        |      OWNER-USER       |                        |
|                        | (Ultimate Compliance, |                        |
|                        | Intervals, Records)   |                        |
|                        +-----------+-----------+                        |
|                                    |                                     |
|                                    v                                     |
|              +---------------------+---------------------+               |
|              |                                           |               |
|              v                                           v               |
|   +-----------------------+                   +-----------------------+  |
|   | AUTHORIZED INSPECTION |                   |  REPAIR ORGANIZATION  |  |
|   |     AGENCY (AIA)      |                   | (WPS, Welder Qual,    |  |
|   | (QA/QC Supervision)   |                   | Workmanship, MTRs)    |  |
|   +-----------+-----------+                   +-----------+-----------+  |
|               |                                           |              |
|               v                                           |              |
|   +-----------------------+                               |              |
|   | AUTHORIZED INSPECTOR  |<------------------------------+              |
|   | (Visual, Calculations,|    Witnesses NDE, Reviews WPS/PQR,           |
|   | Report Sign-Off)      |    Authorizes Return to Service              |
|   +-----------------------+                                              |
+-------------------------------------------------------------------------+

1. The Owner-User Organization

The owner-user is the organization that owns or operates aboveground storage tanks. Under API 653 Section 4 and Section 6, the owner-user carries ultimate responsibility for:

• Maintaining an updated, documented Quality Assurance / Quality Control (QA/QC) inspection system.
• Creating and archiving permanent tank records throughout the operating life of the equipment (construction drawings, baseline thicknesses, repair dossiers, settlement logs, and product service history).
• Establishing formal inspection frequencies and out-of-service intervals in accordance with API 653 limits or Risk-Based Inspection (RBI) standards (API RP 580/581).
• Approving engineering calculations, down-rating decisions, and major repair or alteration designs prior to field execution.

2. Authorized Inspection Agency (AIA)

The API 653 Section 3 definitions define an authorized inspection agency as any one of the following four distinct entities:

• Category 1: The inspection organization of an owner-user who maintains an internal inspection department dedicated to its own operating facilities.
• Category 2: An inspection organization of a jurisdiction (state, municipal, or regional government entity enforcing boiler and pressure vessel/tank safety laws).
• Category 3: An independent inspection organization licensed or recognized by the jurisdiction in which the storage tank is operated.
• Category 4: An independent inspection organization operating under direct contract to the owner-user, providing certified third-party inspection services.

3. The Repair Organization

A repair organization (defined in the API 653 Section 3 definitions) is any contractor or owner-user maintenance force executing repairs or alterations. The repair organization is strictly responsible for:

• Providing materials, certified Mill Test Reports (MTRs), and components that conform to API 650/653 material specifications.
• Establishing and maintaining qualified Welding Procedure Specifications (WPS) supported by verified Procedure Qualification Records (PQR) conforming to ASME Section IX and API 650.
• Ensuring all welders and welding operators hold valid Welder Performance Qualifications (WPQ) and maintain continuity logs per ASME Section IX.
• Executing all cutting, fitting, preheating, welding, and post-weld heat treatment in strict compliance with the approved repair scope and API 653 requirements.

---

Comparison Matrix: Duties Across Organizations

The following matrix summarizes the jurisdictional division of responsibilities under API 653: