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API 510 vs 570 vs 653: vessel, piping and tank certifications compared

Long Seam editorial teamSources checked 9 min read

✓ Checked 21 Oct 2026 against API's API 510, API 570 and API 653 certification pages, ICP Schedules & Fees, and the current Publications Effectivity Sheets and Bodies of Knowledge for each program.

API runs three in-service inspector certifications that are often weighed against each other: API 510 for pressure vessels, API 570 for piping and API 653 for aboveground storage tanks. They share an eligibility pattern, an exam format, a fee row and a recertification cycle. The differences are in the equipment, the qualifying experience and the reference publications. This page sets the published facts side by side so you can see where the programs actually diverge.

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.

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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.

EducationMinimum experienceWhat the experience must include
Bachelor's or higher in engineering or technology, or at least 3 years of technical military service1 yearSupervising or performing inspection under the program's own code
Two-year engineering or technology degree or certificate, or 2 years of technical military service2 yearsWork on the program's equipment, including 1 year supervising or performing that inspection
High-school diploma or equivalent3 yearsAs the row above
No formal education5 or more yearsAs the row above

✓ 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.

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 do not state that limit in the same words, so check the sheet for your program before relying on any section being available.

✓ 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 page has tabs labelled 2026 Fees and 2027 Fees; the tables themselves carry no year, so the years below follow page order.

Fee2026 member / non-member2027 member / non-member
Initial certification$875 / $1,125$890 / $1,140
Recertification$745 / $855$760 / $870
Reschedule$350 / $350$350 / $350
Late application$200 / $200$200 / $200

Confirm which table applies to your application before paying. 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. The API 510 page 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. The sheet's title is the only window label it carries, so check 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:

PublicationNovember 2026 window2027 windows
API 65013th edition (March 2020), Errata 1 (January 2021)14th edition (August 2025)
API 6535th edition (November 2014), Addenda 1 to 3, Errata 1 and 2Same, plus Addendum 4 (July 2025)
RP 5755th edition (September 2024)Same, plus Addendum 1 (July 2025) and Addendum 2 (June 2026)
RP 5765th edition (September 2024), Sections 4.3.2 and 6.7 onlySame, plus Addendum 1 (February 2026)
RP 5773rd edition (October 2020)Same, plus Errata 1 (September 2025)
RP 6515th edition (August 2024)Same
RP 6525th edition (May 2020)6th edition (December 2025)
RP 5713rd edition (March 2020), Section 2 and 10 listed paragraphsSame
ASME BPVC2023 edition, Section V (Articles 1, 2, 6, 7 and 23, SE-797 only) and Section IX (welding only)2025 edition, same sections

✓ 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.

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 pressure vessels are your route, start with the API 510 requirements and cost guide, then try the free 10-question check to see where your preparation stands. The Long Seam overview sets out the full preparation sequence.

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Facts checked 21 October 2026 against the sources listed above. If something has changed, tell us and we will correct it within 2 business days.

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Requirements, fees and payThe publications effectivity sheet: which editions and sections are on your examRequirements, fees and payThe API RP 571 damage mechanisms on the API 510 exam, with where each shows and how it is foundRequirements, fees and payAPI 510 exam windows, fees and the 6-month application ruleRequirements, fees and payAPI 510 pass rates by exam window (from API's published statistics)Requirements, fees and payPressure vessel inspector pay (BLS and posted salaries)Requirements, fees and payAPI 510 certification: requirements, total cost and how long it takes