API653 Reference Materials Allowed on Exam 2026

What "Open Book" Actually Means on the API653 Exam

The phrase "open book" sounds reassuring until you sit down to a 3.75-hour section with 60 code-application questions and realize that flipping through hundreds of pages of standards under time pressure is a skill in itself. The API653 exam - formally the API Individual Certification Program (ICP) examination for Aboveground Storage Tank Inspectors - is structured around two distinct knowledge environments, and understanding the boundary between them is the first strategic decision every candidate must make.

The total exam day runs 7.5 hours. That block includes a tutorial, a 2.75-hour closed-book segment, a 45-minute lunch break, and then the 3.75-hour open-book segment. The closed-book portion is Domain 1 (Closed-Book Knowledge) and covers 110 questions drawn from memorized principles, definitions, inspection criteria, and regulatory knowledge. The open-book portion is Domain 2 (Open-Book Code Application) and covers 60 questions that require you to look up - and correctly interpret - specific values, formulas, and table entries from the approved reference set.

Knowing exactly which documents are permitted, in what format, and under what annotation rules is not a footnote - it is central to your exam strategy. Candidates who arrive with the wrong edition of a standard, or who have not pre-marked key sections, routinely burn through available time on lookup tasks that should take under 90 seconds.

The Official Reference List: Every Document You Can Bring

API publishes a Body of Knowledge (BOK) document for each certification. The BOK for API653 specifies the exact standards and their edition numbers that will be tested. For the current examination windows, candidates must verify their document editions against the Publications Effectivity Sheet. The core reference set for API653 includes:

• API Standard 653 - Tank Inspection, Repair, Alteration, and Reconstruction (primary reference; the exam is built around this document)
• API Standard 650 - Welded Tanks for Oil Storage (original construction standard; API653 references it extensively for weld joint efficiency, shell design, and materials)
• API Recommended Practice 575 - Inspection of Atmospheric and Low-Pressure Storage Tanks
• API Recommended Practice 571 - Damage Mechanisms Affecting Fixed Equipment in the Refining Industry
• API Recommended Practice 576 - Inspection of Pressure-Relieving Devices (appears in limited scope)
• ASME Section V - Nondestructive Examination
• ASME Section IX - Welding, Brazing, and Fusing Qualifications
• ASME Section II Part A and Part D - Materials (referenced for allowable stress values)

This list is not static. Each exam window can carry forward or retire specific editions of these documents. The only authoritative source is the Publications Effectivity Sheet released by API ICP for the applicable testing window.

How PDF References Work at the Prometric Test Center

This is one of the most frequently misunderstood aspects of the API653 exam. Candidates do not bring physical books to a Prometric testing center. The exam is administered on computer, and the approved reference documents are provided as PDFs on the exam workstation itself. You access them through a viewer integrated into the testing interface during the open-book portion only.

What this means practically:

• You cannot write in the PDFs during the exam. Annotation you made at home in a personal copy does not transfer.
• You can use the PDF viewer's search function (Ctrl+F or equivalent) to locate keywords and section numbers.
• You should know the exact section numbers and table identifiers in advance - searching "minimum shell thickness" will return multiple hits and you need to know which one applies.
• Bookmarks or tabs you have pre-created in a personal study copy cannot be brought in, but familiarity with document structure will make in-exam PDF navigation faster.

If you want to simulate this environment before exam day, our API653 practice test platform is designed around the same timed, question-by-question format you will experience at Prometric. Practicing under realistic conditions builds the navigation speed that the open-book segment demands.

Closed-Book vs. Open-Book: Know Which Domain Uses Which

Roughly one-third of the API653 exam content overlaps with API 510 and API 570 certifications. If you hold either of those credentials, you already have a foundation in ASME Section V and Section IX navigation, but the API 653-specific calculations - particularly the shell thickness retirement criteria - are unique to this exam and require dedicated preparation.

The Publications Effectivity Sheet and Why It Changes Everything

The Publications Effectivity Sheet (PES) is a one-page document that API ICP releases for each testing window specifying the exact edition and addendum of every reference permitted in the exam. For the March 2025 through November 2025 examination windows, the current PES governs which version of API 653, API 650, ASME Section IX, and every other reference is in scope.

This matters for two reasons. First, if you study from an outdated edition, specific table values, section numbers, and formula constants may differ from what appears on the exam PDFs. A shell thickness formula coefficient that changed between editions will produce a wrong answer even if your calculation method is correct. Second, if a new addendum has been issued between when you started studying and when you sit for the exam, you need to know what changed.

Always download the current PES directly from the API ICP website before purchasing or printing any reference material. For candidates planning to test in the later 2025 windows or planning ahead to 2026, check the API653 Exam Schedule and Testing Windows 2026 for the corresponding effectivity sheet dates.

Tabbing and Annotation Rules for Your Printed References

Although the exam itself uses PDFs on the Prometric workstation, studying with physical annotated copies remains the most effective way to build the document familiarity that makes in-exam PDF navigation fast. API ICP permits candidates to bring annotated personal copies to study sessions - but at the actual exam, only the provided PDFs are accessible.

When building your personal study set:

• Tab every section header in API 653 - Section 4 (inspection), Section 5 (tank bottoms), Section 6 (tank shells), Section 7 (tank roofs), Section 9 (repair), Section 10 (alteration and reconstruction) are the highest-frequency open-book lookup zones.
• Mark every formula in API 653 Section 4 with the variable definitions alongside it. Do not rely on memory for what each variable represents under exam pressure.
• Flag Annex B entirely - fitness-for-service assessments for shells and bottoms generate a disproportionate number of open-book questions.
• In API 650, mark Tables 3-2 and 3-3 (allowable stress values and material groups) and the weld joint efficiency section - these are the most common lookup targets for shell design questions that appear in Domain 2.
• In ASME Section IX, mark QW-250 through QW-290 (essential variables for welding processes) and the P-Number and F-Number grouping tables.

Transfer that section-number knowledge into your PDF search habits. When you sit at the Prometric workstation, you are not browsing - you are navigating by known coordinates.

High-Payoff Sections to Pre-Mark Before Exam Day

Not all sections of the reference set carry equal exam weight. Based on the structure of Domain 2 and the topics identified in the API653 BOK, certain sections generate the majority of open-book questions. Prioritize navigation fluency in these areas above all others:

• API 653 Section 4.3 and 4.4 - Minimum shell thickness calculations and retirement criteria. Shell thickness questions are among the most frequently cited critical exam topics. Know the hydrostatic test formula and the retirement thickness formula cold, and be able to locate supporting values (joint efficiency, allowable stress) in under 60 seconds.
• API 653 Section 5 - Tank bottom inspection, minimum thickness for bottoms, annular plate requirements. Bottom replacement criteria appear on virtually every exam administration.
• API 653 Section 9 - Repair methods, weld examination requirements, and insert plate sizing rules. Repair questions often combine a dimensional requirement from Section 9 with a weld qualification requirement from ASME IX.
• API 653 Annex B - Fitness-for-service assessment. Multi-step calculation questions in Domain 2 frequently require Annex B combined with Section 6 (shells).
• ASME Section IX QW-200 series - Welding procedure specification content requirements. These generate lookup questions that appear straightforward but have precise code language that candidates must quote accurately.

Use the API653 practice exam tool to work through shell thickness calculation questions under timed conditions. Repetition builds the retrieval pattern so that on exam day, these multi-step questions feel routine rather than daunting.

Building Your Study Calendar Around the Open-Book vs. Closed-Book Split

The structural split between Domain 1 (memorization-dependent) and Domain 2 (navigation-dependent) should directly shape how you allocate study time across your preparation period. Below is a framework tied to the specific demands of each API653 domain.

The $875 API member / $1,125 non-member exam fee, combined with the significant time investment required to meet the education and experience prerequisites, makes a structured preparation calendar not a luxury but a financial and professional necessity. The approximately 62% historical pass rate reflects that a meaningful proportion of candidates underestimate either the closed-book memorization burden or the open-book navigation speed requirement - rarely both.

Frequently Asked Questions