API 570 Body of Knowledge 2027: What Is on the Exam

How API uses the Body of Knowledge

The Body of Knowledge, or BOK, is not a syllabus of lessons. It is a list of what a question may be drawn from. API states that only information in the listed references, at the editions on the effectivity sheet, is used for questions. It also says that if a document is listed without exclusions, questions may come from anywhere inside it.

Two points change how you study:

• A named paragraph is an aid, not a fence. When the BOK points at a paragraph for a calculation, other paragraphs in that section are still in play.
• Edition beats habit. Your plant may work to a different edition. The exam follows the sheet. Our effectivity sheet guide shows how to read one, and the API 510 Body of Knowledge guide shows the same method on the vessel exam.

The exam itself is 170 questions, 140 of them scored, in a 110-question closed-book part and a 60-question open-book part. The open versus closed book article covers how the two parts differ.

Section I: calculations on in-service piping

This is the section most candidates fear and the one you can improve fastest. The BOK says calculation questions are about existing, in-service piping, not new piping, and that you must be comfortable in both US customary and SI units. The categories include:

• Corrosion rates, remaining life and inspection intervals
• Weld joint and casting quality factors
• Internal pressure and minimum thickness of straight pipe, including permanent blanks and the MAWP of corroded pipe
• Pressure testing, impact testing exemptions, preheat and heat treatment
• Thermal expansion between two temperatures
• Flange wall thickness and working pressure

The BOK says the formulas and interval rules for corrosion rate, remaining life and intervals may be closed-book. Plan to know those cold. Our API 570 calculations article works them with invented numbers. The BOK also lists a long set of B31.3 design topics that are excluded, such as branch connections and flexibility analysis. Read that list once and you can stop worrying about a big slice of the code.

Sections II and III: welding review and NDE

Welding procedure review. You are asked to read a welding procedure specification, a procedure qualification record and a welder performance qualification, then decide whether they fit together. The BOK limits the problems to one process per record and lists the processes as SMAW, GTAW, GMAW and SAW. It says brazing is not covered. Practice with a fixed checklist: variables, mechanical tests, then whether the welder is qualified for the production weld.

Nondestructive examination. The BOK names specific ASME Section V articles for radiography, liquid penetrant, magnetic particle (yoke and prod), visual, leak testing and ultrasonic thickness measurement. Study the main body of each listed article, plus the general NDE rules in B31.3 and API 570.

Sections IV and V: practical knowledge

Section IV is a topic list. It covers organization and certification requirements, types of inspection, welding on piping, corrosion and minimum thickness evaluation, remaining life, intervals, safety practices, records, repairs, alterations and reratings, pressure testing after repairs, flange ratings and positive material identification.

Section V ties each topic to a publication:

• API 570, RP 574, RP 577 and RP 578: the entire document is subject to testing.
• RP 571: Section 2 plus 15 listed paragraphs.
• RP 576: Section 5, Sections 6.1 to 6.5 and Section 7.
• ASME B16.5 and PCC-2: the topics and articles the BOK names.

Because API 570 and RP 574 are fully in scope, they deserve the most reading hours. Our API 570 exam prep article gives an order for working through them.

Turn the outline into a tracker

Copy the five section names into a sheet and add one row per topic. Score yourself from 0 to 2: 0 for "can't do it", 1 for "can do it with the book open", 2 for "can do it in the time the exam gives". Re-score every Sunday.

A worked example with invented numbers. After the first 40 mixed practice prompts, you log:

Section	Prompts	Correct	Share
I Calculations	14	7	50%
II Welding review	6	4	67%
III NDE	6	5	83%
IV and V Practical	14	10	71%

Your first move is obvious: Section I. Take 10 of the 14 calculation prompts again in three days, and log which ones you missed because of a method gap and which because of arithmetic. Your overall mix comes to 26 of 40, that is 65%, which tells you where you stand today and nothing about how an exam will go. Use it to aim your next week.

Next step

Take the free 10-question check at /api-570#q1 to see which Body of Knowledge section to open first. Then see the plans at /api-570/offer#plans, and ask the study buddy at /study-assistant for a plan built around your exam date. If you want the dated version, read the API 570 study plan before 26 November.

FAQ

Where do I find the API 570 Body of Knowledge?

API publishes it on the API 570 certification page. Download the one labeled for your window, since the 2027 version replaces the 2026 one.

Is everything in API 570 on the exam?

The BOK says the entire API 570 document is subject to testing, so treat every section as live. RP 571 and RP 576 are the exceptions with listed portions only.

Are the closed-book formulas in the Body of Knowledge?

The BOK says the formulas and rules for corrosion rate, remaining life and inspection interval may be closed-book. Learn those until you can run them without a book.

Do the Body of Knowledge and the effectivity sheet say the same thing?

No. The BOK lists topics and references. The effectivity sheet lists editions. You need both, and the exam follows the sheet's editions.