API 510 vs 570 vs 653 certification: vessels, piping and tanks compared

Scope: which equipment each covers

• API 510: API's API 510 page describes a knowledge base covering maintenance, inspection, repair and alteration of pressure vessels.
• API 570: the API 570 page describes the same four activities for in-service metallic piping systems.
• API 653: the API 653 page covers aboveground storage tank inspection and repair for candidates meeting the minimum qualifications in API 653.

All three pages say the certification is accredited by ANSI under ISO 17024, is valid for three years and is tested in person at designated centers only.

The Bodies of Knowledge show how the scope turns into calculation topics. The API 510 Body of Knowledge orients calculations toward existing vessels under internal pressure, working from ASME Section VIII, Division 1. The API 570 Body of Knowledge for February and June 2027 orients them toward existing piping, working from B31.3 and B16.5, including flange ratings and thermal expansion. The API 653 Body of Knowledge for 2027 orients them toward existing tanks, with topics such as maximum fill height, shell-opening weld sizes, hot tapping and settlement evaluation from API 650 and API 653.

Eligibility: education and experience

All three programs publish the same four education routes with the same minimum years. What changes is the equipment the experience must involve.

The qualifying equipment work differs in wording on each page:

• API 510: design, fabrication, repair, operation or inspection of pressure vessels.
• API 570: design, construction, repair, operation or inspection of in-service piping.
• API 653: design, construction, repair, operation or inspection of aboveground storage tanks.

Each page says the experience must have been gained within the last 10 years, while employed by or under contract with an authorized inspection agency as defined in that program's code. API 510 points to its Appendix B for that definition. Experience must be documented on the application and is verified. A dishonorable discharge disqualifies military-service credit on all three pages.

Each page ties the experience to its own equipment. If your history mixes vessels, piping and tanks, sort each period by equipment before choosing which application to file. Our API 510 requirements and cost guide works through building that work-history record for the vessel program, and the API 570 requirements, cost and schedule guide does the same for piping.

Exam format and length

The three certification pages publish one format:

• Total appointment: 7.5 hours, made up of a short tutorial, a 2.75-hour closed-book part, a 45-minute lunch and a 3.75-hour open-book part.
• Questions: 170, of which 140 are scored. The API 570 and API 653 pages name the other 30 as pretest questions; the API 510 page says the remainder are pretest.
• Split: 110 closed-book and 60 open-book questions.
• Delivery: computer-based at Prometric centers. Papers and books are not allowed (the API 510 and API 570 pages also name notes); PDFs of the referenced codes and standards appear on screen during the open-book part, in English.

The API 510 page adds that only the sections listed on the effectivity sheet are accessible on screen. The API 570 and API 653 pages word this differently, so use the sheet for your program.

Each Body of Knowledge describes the closed-book part as testing everyday working knowledge of the code and its references, and the open-book part as testing detail an inspector would look up rather than memorize.

Fees

API's Schedules & Fees page lists 510, 570 and 653 in a single row of each fee table, so the three programs cost the same. The years below follow the page's 2026 Fees and 2027 Fees order.

Our API 510 schedule and fees guide covers the separate Prometric appointment-change charges and the application validity rule.

Code editions on the current effectivity sheets

Each program publishes its own effectivity sheet per set of exam windows. The schedule page lists these remaining windows:

• API 510: 2 to 22 January 2027 and 7 to 28 May 2027, both on the current sheet, then 3 to 24 September 2027. API links no sheet for September 2027 yet.
• API 570: 9 to 30 October 2026 (2026 sheet), then 29 January to 19 February 2027 and 4 to 25 June 2027 (2027 sheet), then 8 to 29 October 2027.
• API 653: 6 to 27 November 2026 (2026 sheet), then 12 March to 2 April, 9 to 30 July and 5 to 26 November 2027 (2027 sheet).

API 510. The API 510 sheet covers September 2026, January 2027 and May 2027:

• API 510, 11th edition (October 2022), Errata 1 (March 2023) and Errata 2 (2025)
• RP 571, 3rd edition (March 2020), Section 2 and 15 listed paragraphs
• RP 572, 5th edition (November 2023); RP 576, 5th edition (September 2024); RP 577, 3rd edition (October 2020) with Errata 1 (September 2025); RP 578, 4th edition (February 2023)
• ASME BPVC 2025 edition: Section V (listed articles), Section VIII Division 1 (listed parts and appendices) and Section IX (welding only)
• ASME PCC-2, 2022 edition (14 listed articles)

Our effectivity-sheet guide lists the API 510 article and paragraph limits in full.

API 570. API publishes two sheets. The 2026 sheet is headed "2026", and the 2027 sheet is headed February 2027 and June 2027. The edition lists on the two sheets read the same:

• API 570, 5th edition (February 2024)
• RP 571, 3rd edition (March 2020), Section 2 and 15 listed paragraphs
• RP 574, 5th edition (February 2024) with Addendum 1 (March 2025); RP 576, 5th edition (September 2024), Sections 5, 6.1 to 6.5 and 7; RP 577, 3rd edition (October 2020); RP 578, 4th edition (February 2023)
• ASME BPVC 2023 edition: Section V, Articles 1, 2, 6, 7, 9, 10 and 23 (SE-797 only), and Section IX (welding only)
• B16.5, 2020 edition (issued January 2021); B31.3, 2024 edition (issued December 2024)
• PCC-2, 2022 edition (12 listed articles)

The 2027 sheet names February, while the schedule page's window opens on 29 January 2027, so confirm with API if you test in the January days of that window.

API 653. Here the two sheets differ. The sheet for March, July and November 2026 and the sheet for March, July and November 2027 list:

The API 653 sheets list no PCC-2 and no API 510 or API 570, and the API 510 and API 570 sheets list no API 650. RP 571, RP 576 and RP 577 appear on all three programs' sheets, but with different paragraph or section limits for each.

Recertification

The three certification pages publish one recertification scheme:

• Cycle: every three years through the ICP Portal. Applications open 90 days before expiration, with a 90-day grace period after it; late fees apply. The API 510 and API 653 pages add that with no application by the end of the grace period, the full exam is required.
• Work: at least 20% of time in the most recent three years spent performing or supervising inspection of that program's equipment. Inspectors not actively doing that work must take the full exam.
• Continuing professional development: 24 hours per three-year cycle, relevant to inspection and mechanical integrity, across at least two categories. The API 510 and API 570 pages add that proof goes on the CPD Tracking page in the portal.
• Web quiz: every six years. It is open-book with 25 questions, a four-hour limit and up to three pauses. The API 510 and API 653 pages say one failure allows a retake and a second requires a new application and the full exam; the API 570 page says two failures mean taking the full exam.

The quiz uses a separate recertification effectivity sheet. The API 510 page links one valid from 20 October 2025; the API 570 and API 653 pages link ones effective from 3 April 2023.

Holding API 510 and due for the quiz? The free API 510 recert check refreshes intervals, repairs, records and the RP 571 sections it can reach.

How to get API 653 certification

API 653 follows the same path as the other two, with tank experience in place of vessels or piping:

1. Check your route. Match your education to a row of the eligibility table. For API 653 the experience is design, construction, repair, operation or inspection of aboveground storage tanks, and every route includes at least one year supervising or performing tank inspection.
2. Document the experience. It must be from the last 10 years, while employed by or under contract with an authorized inspection agency as API 653 defines one. API verifies what you list.
3. Apply and pay. Apply through API's Individual Certification Programs portal before your window's deadline. The initial fee is $890 for members and $1,140 for non-members in the 2027 table, and $875 and $1,125 in the 2026 table. A late application costs $200 more.
4. Sit the exam. It is 170 questions over a 7.5-hour appointment at a Prometric center: 110 closed-book, then 60 open-book with API 650, API 653 and the other publications on your window's effectivity sheet on screen. API 653 runs three windows a year, in March, July and November.
5. Keep it current. Recertify every three years with at least 20% of your time on tank inspection and 24 hours of professional development, plus the open-book web quiz every six years.

Long Seam prepares you for API 510 and API 570. It has no API 653 course.

Choosing between them

The published requirements point to the same deciding question: which equipment your qualifying inspection experience is on. The exam day, fees and recertification cycle are identical across the three, so the practical differences are the experience you can document and the reference set you need to buy and learn. If your work is on new pipelines under construction, none of the three fits; our API 1169 certification guide covers that program.

If pressure vessels are your route, start with the API 510 requirements and cost guide. The Long Seam overview sets out the full preparation sequence.

If piping is your route, the free API 570 practice test shows your weakest Body of Knowledge area in a few minutes, with every answer explained.

FAQ

What is API 653 certification?

It is the American Petroleum Institute's Aboveground Storage Tank Inspector certification. It shows you have documented qualifying tank experience and passed API's 653 exam on aboveground storage tank inspection and repair.

How do I get API 653 certification?

Check that your education and tank experience fit one of API's four routes, apply through the ICP portal by your window's deadline, pay the initial fee and pass the 170-question exam at a Prometric center.

What are the API 653 certification requirements?

One year of tank experience with a bachelor's in engineering or technology, two years with a two-year degree or certificate, three with a high-school diploma, or five or more with no formal education. The experience must be from the last 10 years and include at least one year supervising or performing tank inspection.

How much does API 653 certification cost?

API's initial fee is $890 for members and $1,140 for non-members in the 2027 table, and $875 and $1,125 in the 2026 table, the same as API 510 and API 570. Books, preparation and travel come on top.

How long does API 653 certification last?

Three years. You recertify through the ICP portal, and every six years that includes a 25-question open-book web quiz.

When is the next API 653 exam window?

6 to 27 November 2026, then 12 March to 2 April, 9 to 30 July and 5 to 26 November 2027.

Is the API 653 exam the same as API 510 or API 570?

The format, fees and recertification cycle match. The equipment and the references differ: API 653 works from API 650 and API 653 for tanks, where 510 works from Section VIII for vessels and 570 from B31.3 for piping.

Start your API 510 prep

The free 10-question check takes a few minutes, needs no signup and shows which Body of Knowledge domains to study first, with an explanation for every answer. The Long Seam course adds a lesson for each domain, timed practice exams and a study plan from your exam date.

On the piping route instead? Take the free API 570 check. Facing the six-year web quiz? Try the free API 510 recert check.

Sources

Show the list

• API 510 Pressure Vessel Inspector, American Petroleum Institute
• API 570 Piping Inspector, American Petroleum Institute
• API 653 Aboveground Storage Tank Inspector, American Petroleum Institute
• ICP Schedules & Fees, American Petroleum Institute