What Is Not on the API 510 Exam: The Skip List

All of it comes from the API 510 Body of Knowledge for September 2026 to May 2027, read on 26 October 2026. If you test in another window, open that window's edition first, because the lists change.

First, one rule about reading the list

The Body of Knowledge says that questions may be taken from anywhere within each listed document unless something is specifically excluded. If a section of a document is named as excluded, every other section in that document is included. So the skip list is narrow and specific, and "not mentioned" never means "safe to skip." Treat only named exclusions as skippable.

Calculations you are not expected to perform

The Body of Knowledge says calculation questions are about existing vessels, not new ones, and only internal pressure loadings are considered. It then lists typical engineering requirements that candidates will not be expected to know for the exam. In plain words, these are out:

• Required thickness for wind, earthquake and other secondary loads.
• Supplementary design formulas for non-cylindrical shell parts.
• External pressure calculations. You should still understand the rules for external pressure design (the Body of Knowledge points to ASME Section VIII, Division 1, UG-28), but you will not be asked to run the math.
• Nozzle calculations for external loads.
• Flange calculations.
• Brazing requirements.
• Ligament calculations.
• Stayed flat heads and sizing of stays.
• Tubesheet calculations and tube-to-tubesheet joints and loads.
• Relief valve sizing.
• Lifting lug and other structural calculations.
• Zick analysis for saddle supports.
• Proof testing requirements.

That is a lot of engineering you can leave to the designers. It also tells you what the calculation questions do cover, so your drill time goes to the list in the Body of Knowledge section I.A: corrosion rate and interval, joint efficiency, static head, internal pressure for shells and heads, test pressure, impact testing exemptions, weld size at openings and nozzle reinforcement concepts. Our calculations guide maps those.

Vessel types and code parts you can set aside

The same exclusion list names several areas outside the exam:

• Cryogenic vessels below -50°F (-45°C).
• Dimpled, embossed, jacketed and non-metallic vessels and assemblies.
• Integrally forged pressure components.
• Requirements for vessels for human occupancy.
• Several ASME Section VIII, Division 1 parts for specific materials and construction types (the Body of Knowledge lists them by part letters such as UF, UB and UNF, among others).
• Code Cases and interpretations.
• Required inspections for new construction, except where they apply to alterations and repairs.
• Rules for natural resource vessels in API 510 Section 9, which the Body of Knowledge also excludes in its practical knowledge section along with Appendix E.

If your day job includes a cryogenic unit or a jacketed reactor, that is useful experience, but it will not earn points on this exam.

Examination methods outside the exam

The nondestructive examination part is limited too. The Body of Knowledge excludes NDE requirements for acoustic emission, eddy current and motion radiography. For magnetic particle, only the yoke and prod techniques are covered. For ultrasonic, the thickness measurement standard (SE-797) is the focus. Our article on NDE for the API 510 exam covers what is in.

Welding limits that shrink the review

Welding procedure review is bounded as well. The exam reviews only SMAW, GTAW, GMAW or SAW, with one process, one filler metal per process and one supporting PQR per WPS. Base metals are limited to P-No. 1, 3, 4, 5 and 8. Dissimilar base metal joints, dissimilar thicknesses and special processes such as overlay and hard-facing are excluded. Brazing is not covered. If you have been reading about every welding process ever written, you can stop. The WPS and PQR review guide keeps to the bounded version.

Damage mechanisms: only the listed sections

API RP 571 is a big book, and the Body of Knowledge says test questions come only from named portions: the terms and definitions plus a list of 15 mechanisms, including amine and caustic stress corrosion cracking, atmospheric corrosion, boiler water and steam condensate corrosion, brittle fracture, chloride stress corrosion cracking, corrosion under insulation, erosion and erosion-corrosion, high-temperature hydrogen attack, hydrochloric acid and naphthenic acid corrosion, sulfidation and wet H2S damage. Everything else in RP 571 is outside the exam. That turns a book of dozens of mechanisms into a short list. The damage mechanisms guide works through it, and the effectivity sheet tells you which edition applies to your window.

What this is worth in hours

Do not guess a number, since your gaps are your own. Do this instead:

1. Print the Body of Knowledge and mark each exclusion in one color.
2. Check your notes and bookmarks. Anything you have spent time on that sits under an exclusion is a candidate to drop.
3. Move that time to the areas the exam names, starting with the ones your diagnostic shows are weakest.

The exclusions can change from one window to the next, so redo this step if you move to another window.

Next step

Take the free 10-question check at /api-510#q1 to see which of the covered areas need work first. Then see the plans at /api-510/offer#plans, and ask Patch, the study buddy, at /study-assistant to check whether a topic you are studying is inside the Body of Knowledge or on the skip list.

FAQ

Do I need to know external pressure calculations for API 510?

No. The Body of Knowledge says you should understand the rules for external pressure design but will not be required to perform external pressure calculations.

Are flange calculations on the API 510 exam?

No. Flange calculations are on the Body of Knowledge list of ASME engineering requirements that candidates are not expected to know for the exam.

Is all of API RP 571 on the exam?

No. The Body of Knowledge names the sections that test questions are based on: the terms and definitions and a specific list of mechanisms. Other sections are outside the exam.

Does "not listed" mean "not tested"?

No. Questions may come from anywhere in a listed document unless a section is specifically excluded. Only named exclusions are safe to skip.

Sources

• API 510 Body of Knowledge, September 2026 to May 2027, American Petroleum Institute: sections I.A, I.B, II, III and V
• API 510 Pressure Vessel Inspector, American Petroleum Institute, with the Publications Effectivity Sheet for each window
• ASME Section VIII, Division 1 (UG-28) and API 510 Section 9, cited by number only