The API-510 exam leads to the Authorized Pressure Vessel Inspector certification, a Professional-level credential from API. It validates the skills measured by the API Pressure Vessel Inspector syllabus and is a recognized step for IT professionals building their careers, and it sits alongside related credentials such as API 570 Piping Inspector, API 653 Storage Tank Inspector, API 571 Damage Mechanisms, API 576 Pressure Relieving Devices.

The API Pressure Vessel Inspector exam includes 170 (140 scored + 30 unscored pretest; 110 closed-book + 60 open-book) questions and gives you 450 (total exam day: 7.5 hours; 165 min closed-book + 225 min open-book + 45 min break) to complete them. That works out to a fairly tight pace, so reading each question carefully but decisively matters more than perfectionism. If a question stalls you, flag it and move on; banking the easier points first keeps time pressure from snowballing near the end. Before test day, run at least one full timed session with the TestKingFree practice test so the rhythm feels familiar rather than rushed.

You need 550 (scaled score, range 200–750) to pass the API-510 exam, and the official registration fee is $875 (API member) / $1,125 (non-member) USD. Keep in mind that a failed attempt means paying the full fee again to retake the exam, so it pays to be honest with yourself before booking a seat. A practical benchmark: work through the 175 practice questions at TestKingFree until you can score comfortably above the passing line in timed mode, then schedule your exam.

Education + experience: BS/Eng Tech: 1 year; 2-yr degree: 2 years; High school: 3 years; No degree: 5 years. All require minimum 1 year performing/supervising pressure vessel inspection work within last 10 years Because API may adjust its policies over time, we recommend confirming the latest requirements on the official exam page (official exam page) before you register.

You can sign up for the API Pressure Vessel Inspector exam through any of the official registration channels below:

• API Certification Portal
• Prometric Scheduling

As for how the exam is delivered: In-person computer-based test at Prometric authorized centers worldwide; no remote testing available.

API suggests the following training options for candidates preparing for API Pressure Vessel Inspector:

• API Official Training Resources
• API 510 Body of Knowledge

Formal training is a solid foundation, and pairing it with the 175 practice questions from TestKingFree helps you turn that knowledge into exam-day confidence.

Yes. TestKingFree offers a free PDF demo of the API Pressure Vessel Inspector material, so you can review the question style and answer quality before making a decision. Every purchase also includes 365 days of free updates, and after that period you can extend your updates at a 50% discount, which keeps your preparation current through 2026 and beyond.

If you take the API Pressure Vessel Inspector exam within 60 days of your purchase and do not pass, TestKingFree offers a full refund under its Money Back Guarantee. To apply, send a scanned copy of your exam enrollment slip together with your official Score Report in PDF format within 2 days of the exam date, and your claim will be processed within 7 days. The guarantee applies only to the corresponding exam: attempts made within 3 days of purchase, exams downloaded but never actually taken, free materials, and expired orders are not eligible, and the candidate name must match the purchaser name. If you would rather not take a refund, you can exchange your product for two additional exam preparation products of equal value and keep the update service on your original purchase. Delivery itself is instant: your product is available for download right after payment and is also sent to your email within one minute, and if it has not arrived within 2 hours, contact our support team. There is no limit on how many computers you can install it on.

The API Pressure Vessel Inspector syllabus is divided into 5 main domains, including Design, Materials, and Fabrication Rules (22%), Fitness-for-Service, RBI, and Pressure Testing (12%), Repairs, Alterations, Rerating, and Mechanical Integrity (16%). Each domain carries a different share of the total score, so knowing where the weight sits helps you allocate your study time wisely. You will find the complete, up-to-date outline in the Exam Topics section above.