API Inspector Guide 2026: API 510 vs 570 vs 653

API 510 vs 570 vs 653: the verified facts, checked against api.org

API 510, API 570 and API 653 are three separate API Individual Certification Program (ICP) credentials. Each covers one equipment class in service: pressure vessels, process piping or aboveground storage tanks. None is a prerequisite for another. Pick the one that matches the equipment your employer's or client's contracts actually name. The figures below come from API's public program pages as of October 2026. Where anything on this page or elsewhere disagrees with api.org, api.org wins.

Two corrections to common myths. First, the exams are not fully open-book. The closed-book portion comes first and carries most of the questions, so memorised rules such as interval logic and calculation steps matter as much as code navigation. Second, renewal is not "re-exam or professional development hours". It is work-percentage evidence plus CPD, with a short web quiz every six years. A certificate that lapses past API's grace arrangements generally means applying again.

Sources: API 510 program page, API 570 program page, API 653 program page, ICP program updates.

Which one fits your work: a decision guide by equipment and employer

Choose by the equipment your inspection hours are spent on, because the experience requirement and the recertification work percentage are both tied to that equipment class. Vessel-heavy refinery units point to API 510, piping circuits to API 570, and terminals and tank farms to API 653.

• Refinery or chemical plant inspection group. Vessels drive turnaround sign-offs, and piping drives continuous CML work. Many groups want both API 510 and API 570 among their inspectors of record. Which comes first depends on what the inspector will actually sign.
• Midstream terminal, tank farm or bulk liquid storage. API 653 is the natural first credential. Experience on tank inspection, repair or construction counts toward it, and the tank programme is what auditors will check.
• Pipeline construction. None of the three. API 1169 Pipeline Construction Inspector covers new onshore pipeline construction inspection, with its own experience routes and a 3-hour exam at test centres.
• Welding-focused QA/QC. API 577 (Welding Inspection and Metallurgy) is a stand-alone credential. Holders of 510, 570 or 653 qualify automatically; otherwise eligibility is education plus petrochemical experience. It is delivered at test centres or by remote proctoring. AWS CWI is the usual fabrication-side credential.
• Corrosion and damage mechanisms. API 571 complements any of the three and has been stand-alone since 2013, so it no longer requires a 510, 570 or 653 certificate.

Whatever the API credential, the readings an inspector evaluates come from NDE technicians qualified under an employer written practice, usually based on ASNT SNT-TC-1A. That is a separate qualification path, and many inspectors hold both. See ASNT certification and NDT Level II training.

"What's the easiest API certification for a welder with no QC experience?"

None of API 510, 570 or 653 is open to someone with no inspection experience. Each requires at least one year in inspection supervision or performance on the non-degree routes. Realistic first steps for a welder are an entry credential with no experience bar, such as API 936 refractory, or an NDT Level I/II path that builds countable inspection experience.

Welding experience is valuable but is not, on its own, inspection experience as API counts it. For a high school graduate, API 570 and API 653 need three years of relevant experience, at least one of them in inspection, gained while employed by or contracted to an authorized inspection agency. The practical routes are:

1. Move into an inspection or QC role first. Weld inspection, NDT assistant or QC technician roles on the employer's or client's inspection team start the experience clock for the equipment class you work on.
2. Build NDT method qualifications. VT, PT and MT at Level I and then Level II under an SNT-TC-1A written practice give a welder a credible inspection role and documented hours. UT thickness follows naturally for piping and tank work.
3. Consider credentials with lower entry bars. API's public page for API 936 (refractory personnel) states no specific education or experience verification for initial certification, and the exam can be taken remotely. API 577 needs petrochemical industry experience but not inspection-agency experience. AWS CWI suits welders who want to stay on the fabrication side.
4. Target API 570 or 653 once eligible. Choose the one that matches the equipment you have been inspecting. Piping work is plentiful at most plants, and tank work dominates terminals.

For a fuller comparison of first credentials see API 936 vs API 653 as a first certification and the welder-to-NDT-inspector career path.

Should an enterprise mandate API 510, 570 and 653 as the minimum for every in-service inspection role?

A blanket global mandate is easy to write and hard to defend. API ICP credentials are the clear benchmark where API codes are the governing RAGAGEP or are referenced by regulation. Elsewhere, jurisdictional schemes may be required or be legitimately equivalent. A defensible policy names the role, the equipment, the governing code and the jurisdiction, then sets the credential and a written equivalency route.

The questions inspection managers ask, such as "is mandating 510, 570 and 653 for all in-service inspection roles across a global portfolio too rigid?", usually hide three separate decisions:

• Which roles sign? An API credential matters most for the person who acts as authorized inspector and signs evaluations, intervals and repair acceptance under API 510, 570 or 653. NDE technicians, data analysts and inspection planners need different qualifications.
• Which code governs the asset? In the US, OSHA PSM requires inspection to RAGAGEP. Where the site cites API 510, 570 or 653, the codes themselves define the authorized inspector by reference to their certification annexes, so an API credential is the straightforward evidence. Where a jurisdiction runs its own inspector scheme, local rules take precedence. In Canada, for example, Ontario requires in-service inspections under its regulation to be done by holders of an Ontario Certificate of Competency, and Alberta applies API codes through ABSA's owner-user requirements.
• How will equivalence be judged? If the policy allows "equivalent qualifications", write down the evidence required (scope match, exam, experience, recertification and verification route) and who approves it. Case-by-case acceptance without written criteria is what fails audits.

A structure that holds up in writing: specify API 510, 570 or 653 for authorized-inspector roles on assets where the API code is the governing in-service code. Specify the jurisdiction's own credential where regulation requires it. Allow documented equivalence only through a named approver against written criteria. Require active-status verification through API's public inspector search, or the equivalent registry, at contract award and at each renewal. Large operators do not generally publish their internal certification standards, so be wary of claims about what a specific major "requires". Ask that operator's contractor qualification team instead. A longer treatment is in writing a defensible inspector certification policy.

"Should we require API 653 for every tank inspector on our contracts?"

Require API 653 for the inspector who directs formal external and internal inspections and signs the evaluation, because the standard ties those duties to a certified authorized inspector. Do not require it for every person on the crew. Routine monthly checks and NDE work have their own, different qualification rules.

API 653 separates routine in-service inspections, which owner/operator personnel who are not authorized inspectors may carry out, from formal external and internal inspections directed by an authorized inspector. NDE on the tank is performed by examiners qualified under API 650's rules and the owner's specification. A defensible contract clause therefore reads roughly as follows:

• The inspector of record for formal API 653 inspections holds an active API 653 certificate, verified on API's public directory before mobilisation.
• NDE personnel hold method qualifications (for example UT, MT, PT, MFL floor scanning) under a written practice the contractor can produce, with the Level III named.
• Any proposed equivalent is submitted in writing with evidence and approved before work starts.
• For breakout tanks under PHMSA rules or tanks in SPCC programmes, the inspection standard and personnel qualifications are consistent with the regulation.

That gives you a position you can put in writing without excluding qualified NDE crews or relying on a single credential to cover work it was never designed for.

Offshore groups: API 510 vs AMPP CIP, and which two to fund first

API 510 and AMPP CIP certify different things. API 510 covers the in-service integrity of pressure vessels. CIP covers coating inspection: surface preparation, application and coating testing. For an offshore inspection group, the right two credentials depend on what operators' contracts and the regulator's reporting actually ask for, not on which credential is more prestigious.

Offshore topsides combine pressure vessels, process piping and heavy atmospheric corrosion. That is why both credentials appear in operator pre-qualification requests. AMPP's CIP Level 2 (Certified Coatings Inspector) requires CIP Level 1, two years of coatings-related work experience and completion of the Level 2 course, and it recertifies every three years. API 510 requires vessel inspection experience gained with an authorized inspection agency and an in-person Prometric exam.

A practical way to choose under a fixed budget:

1. Read the scopes you are bidding. Count how many operator scopes name an API inspector of record for vessels or piping, and how many name coating inspection.
2. Fund the signature role first. If you cannot supply an inspector of record, you cannot bid the scope at all. That is usually API 510 or API 570 for topsides integrity work.
3. Fund the volume role second. Coating inspection campaigns and piping CML programmes generate steady hours. CIP or API 570 often fills that slot.
4. Check the contractor pre-qualification platform. Operators set requirements in their ISNetworld or similar subscriptions. Company-level programmes such as safety statistics, written practices and quality systems frequently weigh as much as individual certificates.

The "Gulf of America" name is a naming change for US federal usage and does not alter technical inspection requirements. For BSEE reporting, the merged AMPP programme and budget splits, see API 510 vs AMPP CIP for offshore pre-qualification.

How to verify an inspector's API certificate before you rely on it

API publishes two free tools: an ICP directory that lists certified individuals by program and country (and by state or province for the US and Canada), and an inspector status verification search by last name or certification number.

Run the check at contract award and again before each mobilisation. Certificates run on three-year terms and can lapse between projects. Record the result in the job file, because OSHA PSM documentation and client audits both expect evidence of qualification, not just a copy of a certificate. Use API's Find an Inspector page.

Where Atlantis fits

Atlantis does not provide API certification training or exam preparation, and we are not an authorized inspection agency. What we do: NDE inspection services (UT thickness and CML surveys, corrosion mapping, PAUT, TOFD, MFL tank-floor scanning, MT, PT, RT through licensed crews) performed by ASNT-certified technicians under ASNT Level III oversight, with results delivered to your API 510, 570 or 653 inspector of record. We also provide ASNT SNT-TC-1A NDT training, the complementary path that builds countable inspection experience; 1,000+ technicians trained. Request NDE support for your inspectors or ask about ASNT NDT training for your team. We reply within one business day.

More questions inspection managers ask

Which API certification should I get first: 510, 570 or 653?

The one that matches the equipment you have been inspecting. The experience requirement and later recertification are both tied to that equipment class. Vessel-heavy refinery roles point to 510, piping roles to 570, and terminal and tank-farm roles to 653.

Can I hold API 510, 570 and 653 at the same time?

Yes. They are independent credentials, each with its own eligibility, exam and three-year term. Recertifying each one requires evidence of inspection work on that equipment class.

If I can only fund two API certifications for an offshore team this year, which two?

Fund the credential that lets you supply an inspector of record for the scopes you bid, usually API 510 or 570 for topsides, then the one that matches your highest-volume work, often API 570 or a coatings credential. Base the choice on the operator scopes in front of you. Talk to us about offshore NDE support.