Well-prepared API 510 candidates lose more marks to the way the exam day is built than to any single topic. The three free questions on this page, and the rest of it, are about that gap.
API 510 The distractor on this one catch four candidates out of five. Watch on YouTube · CertCrafter What do these free API 510 questions test?
The three questions cover a weld repair, an insulation call and a radiograph, in three parts of the Body of Knowledge: welding evaluation, general practical knowledge and specific practical knowledge. None asks you to recite a number. Each puts you in front of a decision with a constraint attached, which is how API 510 reads on the day.
All come from the free sample behind the scored API 510 quiz. Take them cold and commit to an answer before you open the explanation.
How do inspectors handle a repair where heat treatment is impractical?
Postweld heat treatment is the textbook answer, and plants often cannot do it. The engineer specifies the method, the welding procedure covers it, and the inspector checks that what happens on the shell matches the paper. ASME PCC-2 Article 209, alternatives to postweld heat treatment, is on the effectivity sheet.
Candidates lose this one by treating the code as a list of prohibitions. It is closer to a list of conditions. When a stem says the usual method is impossible, look for what the code offers in its place and who is allowed to choose it.
Where does corrosion under insulation get found?
Mostly where somebody went looking. Corrosion under insulation hides behind the jacket, so a sound-looking vessel can be losing metal for years. Inspectors rank their effort by temperature and by cycling, because water that dries and rewets the steel does the damage. On a turnaround, the call is where one hour of scarce access buys the most information. RP 571 section 3.22 lists the mechanism for the exam, and RP 572 covers inspection practice for vessels. The second question asks you to place that hour.
How should you read a radiograph question?
By the character of the indication first, the size second. Cracks, incomplete fusion and incomplete penetration are planar. Slag and porosity are volumetric. The code treats the two families differently, and the exam leans on that difference.
On a job, the examiner reports and the inspector decides, with ASME Section V, Article 2 for the method and Section VIII Division 1 for acceptance. The third question baits you with a measurement. Ask what kind of flaw it is, and the number stops mattering.
How is the API 510 exam structured?
The exam day is 7.5 hours at a Prometric test center: a short tutorial, 2.75 hours closed book, a 45-minute lunch break and 3.75 hours open book. There are 170 questions, 110 closed book and 60 open book, and 140 are scored. The 30 pretest items are not marked, so every question gets full effort.
No papers, notes or books are allowed. PDFs of the listed code sections appear on screen in the open-book portion only, so rehearse on screen.
What score do you need to pass API 510?
A scaled 400 on a 200-500 scale. API publishes no raw percentage, so treat any “you need 70 percent” advice as a guess.
Which calculations should be in your head before the clock starts?
The Body of Knowledge expects you to calculate metal loss, corrosion rate, remaining corrosion allowance and remaining service life, and to set the inspection interval from Section 6, in both US customary and SI units. API says those formulas may be closed book.
Static head catches people who skip the picture. With a specific gravity of 1.0, the static head on a part is 0.433 psi per foot times the height of liquid above it, and the total on that part is the MAWP at the top plus that head. The vessel part MAWP has to cover that total, which is why API asks you to know vessel MAWP from vessel part MAWP (ASME Section VIII, UG-98).
A stem that gives elevations is telling you to add head. The API 510 Complete Exam Kit drills these calculations, with every answer explained.
Which code editions apply from September 2026 to May 2027?
The sheet for these windows lists API 510, 11th Edition (October 2022) with Errata 1 and 2, API RP 571, 572, 577 and 578, the 2025 ASME code (Sections V, VIII Division 1 and IX) and ASME PCC-2, 2022. Practice material written to an older sheet can point you at requirements that no longer apply.
When are the API 510 exam dates and fees?
The September 2026 window has closed. The next three:
| Exam window | Application deadline |
|---|---|
| January 2 - 22, 2027 | October 29, 2026 |
| May 7 - 28, 2027 | March 4, 2027 |
| September 3 - 24, 2027 | July 2, 2027 |
Initial certification on API’s 2027 schedule is $890 for API members and $1,140 for non-members, and a late application adds $200. Detail is on API’s certification page and schedules and fees page. The exam format, scoring and dates post has more.
How should you use three free questions?
Not as a readiness test. They can expose a habit. Read every explanation, including on the ones you got right. When you miss one, log it by Body of Knowledge section and by the kind of mistake.
The channel has a short on the distractor that catches most candidates. API 510: The 10 Most Common Mistakes and API 510 Formulas With Worked Examples go further. The API 510 guide has the full fact sheet, and the hub of API 510 guides lists the rest.
What these questions will not do
None is copied from a live exam. They are original, written from the published Body of Knowledge and the referenced codes, and no practice set replaces the codes themselves. The API 510 practice test bundle gives full-length runs in the real rhythm. The API 510 Complete Exam Kit works more of these under timed closed-book and open-book conditions, with every answer explained.
Comments
Comments are read by a person before they appear. How we moderate.