For pressure vessel inspectors taking the API 510 exam
API 510: beat the clock to the section
Free API 510 practice: 10 questions, answers explained as you go, score by domain.
Full course $199: 617 practice questions, each explained. See the course
Terms and refunds · Secure checkout by Stripe · Billed by Nori Software
IV. Practical knowledge - general
Which hydrotest situation carries the highest brittle fracture risk?
Press A-D or 1-4 to choose an answer while this question is on screen.
Choose an answer to begin
The exam is open book, so finding the section fast is the skill. Practice to the Sept 2026 Body of Knowledge with the free 10-question check, every answer explained as you go.
- No signup · No card
- Written to API 510's Sept 2026 Body of Knowledge
- Paid to API, not us API 510 exam fee $875–$890 member, $1,125–$1,140 non-member
- API 510 May 2027 window: apply to API by 4 Mar 2027
- 10 questions, untimed
- Answers explained as you go
- Scored by domain
Want a timed run? Try the free 25-question mini-mock. The first 5 need no email.
Every question is original and written to American Petroleum Institute's published content outline.
How it works
- Answer 10 questions, freeUntimed. Check each answer to see why it's right, with a hint where one helps.
- See your score by domainBroken down by outline domain, with your weakest one named.
- Study what you missedAdd your email and exam date for a study plan, or practice at exam pace.
Want exam pace? Take the 25-question practice test (about 57 minutes)
The API 510 course
Available now · instant accessLearn every Body of Knowledge section, work the calculations step by step, then prove it on timed exams.
- 8modules of lessonsEvery task on the outline
- 2full-length timed exams170 questions in 390 minutes each
- 617practice questionsEach one explained
- 6worked calculationsStep by step
- 1week-by-week study planSet to your exam date
Patch, your AI study assistant, comes with the API 510 course: a week-by-week plan from your exam date and weak areas, step-by-step walk-throughs and a weak-spot quiz. Up to 40 messages a day.
- My study plan: a week-by-week course from your exam date and weak areas, with today's set ready. Lose a week and I re-plan it
- Stuck on a question? Tap Walk me through it, Explain like I'm new or Show a worked example
- A quiz on your weak spots, your misses back on a spaced review, and explain it back to me to lock it in
- After 30 answers, I show you the patterns in your misses and a practice set for each one
- Exam week: a day-by-day plan for your last 7 days
See all 8 modules
- API 510: scope, the inspector, repairs and rerating
- Corrosion rates, remaining life and inspection intervals
- Required thickness and MAWP under Section VIII Division 1
- Pressure testing and impact test exemptions
- Welding procedures, qualifications and welding practice
- Nondestructive examination
- Damage mechanisms, materials and vessel inspection practice
- Relief devices, material verification and repair methods
Instant access. Terms and refunds · Secure checkout by Stripe · Billed by Nori Software
Look inside the course
The real course screens you get after checkout, shown here with sample questions and answers.
Timed exam with flagsA countdown clock, a flag button on every question and a navigator that shows what you answered and flagged. Review every missAfter the exam, open any question you missed to see your choice, the correct answer, why, and the code section to read. Readiness by domainEach domain rated from your own answers, with a one-click drill where you need work.
Every answer comes with a full explanation.
Also free
AI study assistant
Ask Patch why an answer is right
AI study assistant
Patch AI
Patch is your AI study assistant. Answer a question, then ask Patch why.
Example
Why is that one wrong?
PatchI'll show you why the right answer works, why each other option falls short, and where to look it up.
Example of how I explain. Answer question 1, then tap Ask Patch why. 3 free asks, 10 more with your email. I'm AI, so check important details against your references. Meet Patch
Exam at a glance
- Format
- 170 questions in 390 minutesBook: Closed-book part + open-book part; only the sections listed on the Publications Effectivity Sheet are available during the open-book part. Calculator, scratch paper and pencil provided; own papers and reference books not allowed
- Delivery
- Prometric computer-based test, in person at designated test centers only (API 510 is not available for remote testing)
- Exam fee (paid to API, not us)
- Initial: 2026 $875 member / $1,125 non-member; 2027 $890 / $1,140. Late application $200. Reschedule (new window) $350
- Retakes
- No published attempt limit or waiting period. Each application is valid 6 months from the first requested exam date; after it expires a new application and full fee are required. API does not disclose failed exam contents
What it covers
The free 10-question check follows these domains, subject to the available practice questions.
API 510 exam prep FAQ
How long is the free 10-question check?
The free check has 10 practice items, is untimed and takes about 23 minutes. You see the answer and explanation after each item. It is a short study check, rather than a full-length exam simulation. Want exam pace? The 25-item practice test is also free. You can pause it, and it saves your place.
What does the API 510 free check cover?
The check groups practice by the API 510 Body of Knowledge for pressure vessel inspector preparation. The exam has a closed-book part (110 items) and an open-book part (60 items) that allows only the sections on your window's Publications Effectivity Sheet. It is a short study check, not a full exam simulation. Use the Body of Knowledge and Publications Effectivity Sheet for your exam window when choosing references.
Is the 10-question check free?
Yes. You can start the check and see your score and weakest domain for free, with no signup or payment. Your score in each domain unlocks when you add your email.
Where does the practice content come from?
Every question is original and written to API's published outline. Treat the results as a starting point for study.
How is the check scored?
Practice items are grouped by the published outline's domains, subject to available questions. The outline does not publish domain percentages, so the check uses equal domain weights; these are practice weights, not published exam weights. This practice percentage helps set study priorities; it does not predict your exam score or certification outcome.
What do I see after finishing?
You get your score, your weakest domain and what the course holds for it. Add your email to see your score in each domain and get a free study plan.
How should I use the result to study?
Start with your weakest domain. The course has lessons, explained practice items and timed exams on it. Want to test your pace first? Take the free 25-item practice test.
The Long Seam app for iPhone and AndroidToday's questions and your study plan in your pocket. Long Seam already works in your phone's browser today.
See it on your phoneMore free help
- API 510 exam guideFormat, domains, references and published sources in one page
- Free sample lesson
- Free flashcards
- Question of the day
- Print the study checklist (free PDF)Topics to cover, on one printable page. No email.
- Print the flashcards as cut-out cards (free PDF)The free flashcard sample, ready to cut and carry.
- Add API exam deadlines to your calendar (free)Application deadlines and testing windows, no email
- API 510 eligibility checker and exam windowsFree tool
- API 510 damage mechanism quizFree tool
- API 510 lookup drill: find the section or table on a clockFree tool
- API 570 free 10-question check
- API 510 recert free 10-question check
- API 653 free 10-question check
- API 571 free 10-question check
Add this check to your site
Give your students or members the free 10-question API 510 check on your own page. Copy this HTML with its attribution link. Scores open in a new tab on Long Seam. Paste both lines; if your site strips scripts, the frame keeps a fixed height.