API 510 Recertification Quiz: How to Prepare in 2 Weeks

What the quiz is, and what API does not say

Facts from API's page: 25 questions, open book, four hours in total, pause or interruption up to three times. A first failure lets you retake it once. A second failure means a new application and the full exam. You log in with your ICP Portal username and password, and you can take it before or after you submit your recertification application.

Things API's page does not state, so this article does not claim them: a pass mark and any proctoring arrangement. If a forum post gives you a passing score, treat it as unconfirmed. Ask API at the address on its page if you need to know.

Four hours for 25 questions is 240 minutes, or 9.6 minutes each. That is a generous allowance for an open-book test, so the skill is not speed alone. It is finding the right rule in the right edition and reading the stem carefully.

Step 1: get the sheet and set up your copies

API's recertification sheet lists the editions the quiz follows:

• API 510, 11th edition, October 2022, with Errata 1 (March 2023) and Errata 2 (June 2025)
• RP 571, 3rd edition (March 2020): Section 2 plus 15 listed paragraphs
• RP 572, 5th edition (November 2023)
• RP 576, 5th edition (September 2024)
• RP 577, 3rd edition (October 2020)
• RP 578, 4th edition (February 2023)

Questions follow the sheet even if your plant works to another edition. Put the edition list on the first page of your reference set. Buy only authorized copies from API's store. Our effectivity sheet guide shows how to read one.

Step 2: mark your errata

Errata correct the printed text of an edition. Download Errata 1 and 2 for your API 510 copy, open each paragraph they name and mark the corrected text so the corrected version is what you read. We cannot tell you what the errata say from API's sheet alone, and we won't guess. Ten minutes on this is worth more than memorizing, because a question written to the corrected text can only be answered from the corrected text.

Step 3: build a section map

In your own copy, note where each of these starts, with the section numbers you find there: definitions, owner/user responsibilities, inspection practices and testing, intervals, evaluation of inspection data, records, and repairs, alterations and rerating. An open-book quiz rewards a map. Use the open-book strategy guide as a model for the drill, then time yourself: any topic taking over two minutes to find goes on a re-drill list.

Step 4: rework the rules the changes sit on

You do not know which rules changed until you read the new edition against your habits. Refresh the base so a change is easy to see:

• Corrosion rate. Long-term from first to latest reading, short-term from the two latest.
• Remaining life. Margin above required thickness, divided by the rate.
• Intervals, repairs, alterations and rerating. Reread each part of your copy with the errata marked.

Worked example (invented numbers). A vessel shell location read 0.620 in. in 2015, 0.571 in. in 2021 and 0.532 in. in 2026. The required thickness is 0.450 in.

• Short-term rate: (0.571 minus 0.532) divided by 5 = 0.0078 in./yr.
• Long-term rate: (0.620 minus 0.532) divided by 11 = 0.0080 in./yr.
• Remaining life on the short-term rate: (0.532 minus 0.450) divided by 0.0078 = 10.5 years.

Do it again with a new year or a new required thickness. The remaining life calculator checks your answer, and the calculations guide shows the setup.

Step 5: the 15 RP 571 paragraphs

Only Section 2 and these paragraphs of RP 571 are on the quiz: 3.3, 3.8, 3.9, 3.11, 3.14, 3.15, 3.17, 3.22, 3.27, 3.35, 3.36, 3.37, 3.46, 3.61 and 3.67. They cover, in order, amine cracking, atmospheric corrosion, boiler water and steam condensate corrosion, brittle fracture, caustic corrosion and cracking, chloride cracking, corrosion under insulation, erosion, high-temperature H2/H2S corrosion, high-temperature hydrogen attack, hydrochloric acid corrosion, naphthenic acid corrosion, sulfidation and wet H2S damage.

API's sheet does not show which of these changed, so read all 15 in your copy. For each, write one line: the material at risk, the driver and what an inspector sees. Our damage mechanisms guide shows the format.

A two-week plan

• Days 1 to 2: sheet, editions, errata marked.
• Days 3 to 4: section map built and timed.
• Days 5 to 8: rules refresh, one calculation set each evening.
• Days 9 to 11: the 15 RP 571 paragraphs, five a night.
• Days 12 to 14: a 25-question timed set at 9.6 minutes each, then review every miss.

Our API 510 study plan is the longer version if you are preparing for the initial exam instead.

Next step

Not sure how many weeks you have? The API recertification window calculator turns your expiration date into the day the quiz opens and the day the grace period ends.

Take the free 10-question check at /api-510-recert#q1 to find the sections you have not used lately. Then see the plans at /api-510-recert/offer#plans, and ask the study buddy at /study-assistant for a plan built around your exam date.

FAQ

How many questions are on the API 510 recertification quiz?

25 questions, open book, with four hours in total. API says it may be paused or interrupted up to three times.

What is the passing score for the recertification quiz?

API's certification page does not state a pass mark, so we do not give one. Contact API at the address on its page if you need to confirm.

What if I fail the quiz?

API says you can take it once more after a first failure. A second failure means you cannot recertify and must submit a new application and take the full exam.

Is the quiz the same as the API 510 exam?

No. The initial exam has 170 questions across a closed-book and an open-book part. The quiz is 25 open-book questions about changes over the past six years.

Which editions does the quiz use?

The ones on API's recertification publications sheet, effective 20 October 2025. Check API's page for the current sheet before you study.