ASME Authorized Inspector vs API Inspector: New Construction vs In-Service
Short answer: they cover different stages of an asset's life. An ASME Authorized Inspector (AI) holds a National Board AI commission and works for an Authorized Inspection Agency. AIs inspect new construction under the ASME Boiler and Pressure Vessel Code, including boiler external piping. An API 570 (or 510/653) inspector is certified by API to inspect in-service equipment. For new process piping under ASME B31.3, the role is the Owner's Inspector, not an AI. Specify accordingly.
Procurement teams often ask this question when drafting piping inspection RFPs, usually after seeing "ASME AI" and "API 570" used as if they were interchangeable. They are not. Choosing the wrong one either adds cost (an AI on work that needs none) or leaves a gap (an in-service programme with no inspector qualified under the in-service code). This guide sets out which credential governs which job, how each is earned, what each person actually does, and how to write the requirement. It sticks to public information from the National Board, API, ASME and AWS. Check code paragraph references against the edition your contract invokes.
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The quick comparison
| ASME Authorized Inspector (AI) | API 570 authorized piping inspector | ASME B31.3 Owner's Inspector | |
|---|---|---|---|
| Life stage | New construction under the ASME BPV Code (Section I boilers including boiler external piping, Section VIII vessels and others) | In-service inspection, repair, alteration and rerating of metallic piping | New construction of process piping under B31.3 |
| Credential | National Board Authorized Inspector Commission (plus endorsements) | API 570 certificate from API Individual Certification Programs | Qualification routes defined in B31.3 itself; no single mandatory certificate |
| Who issues it | National Board of Boiler and Pressure Vessel Inspectors | API | The owner designates the person, who must meet B31.3's qualification options |
| Employment | Must be employed by an Authorized Inspection Agency or another organization the commission rules allow; the commission is tied to that employer | Works for or under contract to an authorized inspection agency as API 570 defines it (often the owner-user's own inspection organization) | Represents the owner; must not represent or be employed by the fabricator or erector unless the owner is also that party |
| Signs | ASME Manufacturer's Data Reports for stamped items | In-service inspection records and recommendations under the owner's API 570 programme | Verifies, on the owner's behalf, that required examinations and tests were done |
| Validity | Commissions renew annually and lapse when employment ends | Three-year term, then recertification | As the owner's procedures require |
What an ASME Authorized Inspector actually is
The National Board issues two inspector commissions. The Authorized Inspector Commission (AI) qualifies the holder to inspect boilers and pressure vessels as the ASME BPV Code requires during construction. The Inservice Inspector Commission (IS) qualifies the holder for jurisdictionally required inspections of installed boilers and pressure vessels in operation. Endorsements, such as the R endorsement for repairs and alterations and the O endorsement for owner-user inspectors, add specific scopes. All of this is set out in the National Board's NB-263, RCI-1, Rules for Commissioned Inspectors (2025 edition).
To get an AI commission, a candidate needs a minimum number of credit points from education and experience. They attend the National Board's AI course, pass its examination and complete on-the-job training. They must also be employed by an Authorized Inspection Agency or another qualifying organization. The employer makes the application jointly with the candidate. Commissions expire each year and are renewed through the employer, and they become invalid when that employment ends. In practice, an AI is not someone you hire as an individual off the street. You engage an Authorized Inspection Agency, and the agency assigns a commissioned AI.
On ASME-stamped work, the AI monitors the certificate holder's quality programme, witnesses hold points such as the pressure test, and signs the data report before the item is stamped. For boiler external piping, ASME Section I keeps administrative jurisdiction: Code stamping, data forms and Authorized Inspection. B31.1 provides the technical rules. The fabricator holds the appropriate ASME certificate (for piping, typically the PP designator), and an AI is involved. Outside boiler external piping, B31.1 and B31.3 piping has no ASME stamp or AI requirement unless a jurisdiction or contract adds one.
Searchers asking about "ASME authorized inspector course cost" should know that the AI course is run by the National Board, and current course and commission fees are published on nationalboard.org. The course alone does not make someone an AI, because the commission depends on qualifying employment. Atlantis does not offer AI or API certification training.
What an API 570 inspector is
API 570 governs the in-service inspection, rating, repair and alteration of metallic piping systems. Its current edition is the 5th, published February 2024. The API 570 certification, run by API Individual Certification Programs, shows that the holder knows that code and its referenced documents (API RP 574, API RP 571, API RP 577, and relevant ASME B31.3 and Section V and IX content). As API currently publishes it:
- Certification lasts three years. The programme is ANSI-accredited.
- The exam is about 7.5 hours long, with 170 questions (140 scored) in closed-book and open-book sections. It is delivered in person at Prometric testing centres.
- Eligibility combines education and piping-related experience, with at least some in inspection.
- Recertification needs a minimum share of working time on piping inspection plus continuing professional development hours.
Check the API 570 page on api.org for current eligibility, fees and exam windows. Under API 570, the inspector develops or works within the owner's inspection plan, evaluates thickness and condition data, and records recommendations, intervals, repairs and reratings. They are not tied to a single agency in the way a National Board commission is. They act as the authorized piping inspector when they work for or under the direction of the owner-user's authorized inspection agency.
New-construction piping: the B31.3 Owner's Inspector
For new process piping, ASME B31.3 Chapter VI separates two functions:
- Examination is the quality control work of the manufacturer, fabricator or erector: visual examination, radiography, ultrasonics and other NDE to the extent the code requires. Personnel performing NDE are qualified and certified for the method under a written procedure, as described in ASME Section V Article 1.
- Inspection is the owner's function. The owner's inspector verifies that all required examinations and tests have been completed and that the piping meets the code and the engineering design.
B31.3 lets the owner designate the Owner's Inspector. That can be the owner, an owner's employee, or an employee of an engineering or scientific organization or a recognized insurance or inspection company acting as the owner's agent. The Owner's Inspector must not represent or be employed by the piping manufacturer, fabricator or erector, unless the owner is also that party. The 2016 edition, for example, listed four qualification routes for the Owner's Inspector:
- ten years' experience in design, fabrication or examination of industrial pressure piping, with partial credit for engineering degree work;
- professional engineer registration plus five years' piping experience;
- AWS CWI or SCWI certification plus five years' piping experience;
- status as an API 570 authorized piping inspector plus five years' piping experience.
Confirm the routes in the edition your contract invokes. The useful point for RFPs is that an API 570 certificate can be one route to qualifying a B31.3 Owner's Inspector for new construction, but only together with the experience the code requires. An ASME AI commission is not what B31.3 asks for.
A development to watch: AWS has announced an ASME B31 Piping Owner's Inspector (COI) certification, developed with ASME. Release is scheduled for the first quarter of 2027. AWS describes it as a formal structure for a role the B31 codes already require, not a new requirement. Its published eligibility includes routes for holders of credentials such as API 570, CWI/SCWI, National Board certifications or a PE. Until it launches and your contract adopts it, specify the B31.3 routes directly.
In-service piping: API 570 and the jurisdiction
Once piping is in service, API 570 is the usual code for process plants. Its inspector is the API 570 authorized piping inspector. ASME B31.3 still matters for repairs and alterations, where API 570 generally relies on the principles of the construction code. The National Board's Inservice Inspector commission and the NBIC mainly cover boilers and pressure vessels and the jurisdictional inspections of them. Piping is covered by NBIC only where a jurisdiction or the owner's programme brings it in. For a fuller comparison of the two piping codes, see ASME B31.3 after start-up: where API 570 takes over.
Pressure vessels follow the same pattern, but with more jurisdictional involvement. ASME Section VIII construction has an AI. In-service inspection is done by an API 510 inspector and/or a National Board IS-commissioned inspector, depending on the state. Our API 510 vs NBIC commissioned inspector article covers the vessel side in depth.
Which credential to specify, by scope
| Scope in your RFP | Inspector credential to specify | NDE personnel to specify |
|---|---|---|
| New process piping, B31.3 (no stamp) | Owner's Inspector meeting a B31.3 qualification route (API 570, CWI/SCWI, PE, or experience, each with the code's experience requirement), independent of the fabricator/erector | Examiners qualified and certified per written practice (ASNT SNT-TC-1A or equivalent) to Section V procedures |
| Boiler external piping, Section I / B31.1 | ASME AI via the Authorized Inspection Agency of the certificate holder; owner's representative as needed | Examiners per Section I / B31.1 and Section V requirements |
| Non-boiler-external B31.1 power piping | Owner's inspection per B31.1 and owner's programme; AI only if a jurisdiction or contract requires | Qualified examiners per B31.1 and Section V |
| New pressure vessels, Section VIII | ASME AI via the manufacturer's Authorized Inspection Agency | Manufacturer's qualified examiners |
| In-service process piping | API 570 authorized piping inspector working for the owner-user's inspection agency | Examiners certified per written practice; ASNT UT Level II for thickness work is common; API QUTE where the owner requires it |
| In-service vessels | API 510 inspector and/or National Board IS commission, as the jurisdiction requires | As above |
| Repairs/alterations of in-service piping | API 570 inspector authorizes and accepts the work under the owner's programme; construction-code principles apply | Examiners qualified for the required NDE and pressure testing |
For model clauses covering several equipment types and the inspector-vs-examiner split, see requiring API certifications in contractor RFPs.
A worked example: one project, three stages
Consider a refinery unit expansion. The new process lines are designed and built to B31.3. A new steam line connecting to a boiler includes boiler external piping. The new lines tie into existing in-service piping that needs hot-tap connections and some replacement spools.
- New B31.3 lines: the owner designates an Owner's Inspector. In this example it is the owner's own API 570 inspector, who has the required piping experience. The erector's QC manages examination. Radiography and other NDE are performed by certified examiners, and the Owner's Inspector verifies the records and witnesses the pressure tests.
- Boiler external piping: fabricated and installed by an organization with the appropriate ASME certificate. Its Authorized Inspection Agency assigns an AI, who witnesses the hydrostatic test and signs the data report.
- Tie-ins to in-service piping: handled under the owner's API 570 programme. The API 570 inspector authorizes the repair and alteration work, and the examination is performed and recorded under it.
One RFP that simply said "ASME AI required" would have brought an AI to work that doesn't need one and missed the Owner's Inspector and API 570 roles that the project actually requires.
Common specification mistakes
- Writing "ASME Authorized Inspector" for new B31.3 piping. B31.3 has no AI or stamp; it has an Owner's Inspector.
- Assuming any API 570 holder automatically qualifies as a B31.3 Owner's Inspector. The code also requires piping experience.
- Letting the fabricator's or erector's employee act as Owner's Inspector when the owner is not the fabricator.
- Asking bidders to "supply an AI" as individuals. Commissions are tied to the Authorized Inspection Agency employing the inspector.
- Requiring API 570 for every NDE technician. Examination personnel need NDE certification, not the inspector certificate.
- Ignoring the jurisdiction. Some states and provinces add registration or inspection requirements to both new construction and in-service equipment.
Regulatory overlay: PSM, states and Canada
OSHA PSM (29 CFR 1910.119(j)) requires covered equipment to be designed, built, inspected and tested to recognized and generally accepted good engineering practices. In practice, that means B31.3 for new process piping and API 570 for in-service piping. States enforce boiler and pressure vessel laws through their chief inspectors, usually using National Board commissions. Piping coverage varies by state, so confirm with your jurisdiction.
In Canada, CSA B51 brings pressure piping under provincial regulators. Designs are registered, and construction and in-service requirements are provincial. In Alberta, for example, ABSA sets pressure piping construction requirements (AB-518), owner-user integrity management requirements (AB-512), in-service inspection requirements (AB-506), and its own In-Service Pressure Equipment Inspector certificate of competency (AB-526) for owner-user programmes. An API certificate is not automatically a substitute for a provincial certificate, so confirm with ABSA, TSSA or your provincial authority.
How Atlantis supports this
Atlantis NDT supplies the examination side of both new-construction and in-service piping work: radiography by crews licensed where the work is, UT and PAUT weld examination, UT thickness and corrosion mapping at CMLs, MT, PT and visual examination. The work is done by ASNT-certified examiners under ASNT Level III oversight, to written procedures, with certifications submitted before mobilization. We report to the owner's inspector, AI or API 570 inspector, whichever the scope requires. Atlantis is not an Authorized Inspection Agency, does not act as Owner's Inspector or API inspector of record, and does not offer AI, API or CWI training. See piping circuit inspection, API 570 inspection support and our API inspector guide.
Request piping NDE examiners for your next project.
Frequently asked questions
For piping inspector qualifications in RFP language, how does a code-body piping inspector certificate compare to ASME Authorized Inspector qualifications?
An API 570 certificate shows competence in in-service piping inspection. An ASME AI commission qualifies the holder to inspect new ASME BPV Code construction, including boiler external piping, while employed by an Authorized Inspection Agency. Specify API 570 for in-service piping and the B31.3 Owner's Inspector routes for new process piping. Use an AI only where the BPV Code or a jurisdiction requires one.
Which one do we specify for in-service piping versus new construction?
In-service: an API 570 authorized piping inspector. New B31.3 construction: an Owner's Inspector meeting a B31.3 qualification route. Boiler external piping: an AI through the certificate holder's Authorized Inspection Agency.
How much does the ASME Authorized Inspector course cost?
The National Board runs the AI course and publishes current fees on nationalboard.org. The commission also needs qualifying employment with an Authorized Inspection Agency or similar organization, so check eligibility before enrolling.
Can an API 570 inspector act as a B31.3 Owner's Inspector?
Recent B31.3 editions list API 570 authorized piping inspector status as one qualification route, combined with required piping experience. Confirm the wording in your contract's edition.
Does B31.3 piping need an ASME stamp or Authorized Inspector?
No. B31.3 has no ASME certification mark for piping and no AI requirement, unless a jurisdiction or contract adds one.
Can an AI also inspect in-service equipment?
Only with the right commission and endorsements, such as the National Board IS commission for jurisdictional in-service inspections of boilers and vessels, or the API certificate for API code work. The AI commission alone covers ASME construction inspection.
What is the new ASME B31 Piping Owner's Inspector certification?
A certification announced by AWS with ASME for the B31 Owner's Inspector role, scheduled for release in Q1 2027. Check aws.org for status before referencing it in contracts.
Do NDE examiners need API 570 or an AI commission?
No. Examiners need certification in their NDE method under a written practice and procedure. Inspector credentials apply to the inspector role.
Who signs off a repair on in-service piping?
Under API 570, the authorized piping inspector authorizes and accepts repairs and alterations within the owner's programme, with engineering involvement as the code requires. Jurisdictions may add requirements.
Is an API 570 certificate valid in Canada?
Provinces regulate pressure piping under CSA B51 and may require their own certificates, such as ABSA's In-Service Pressure Equipment Inspector certificate in Alberta. Confirm with the provincial regulator.
Drafting piping inspection RFP language? Ask our Level III to check the NDE requirements.
Related reading: API 570 piping inspection code requirements and ASME B31.1 power piping explained.
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