The whole Body of Knowledge, and how to find it under exam conditions
API 570 Exam Preparation
Preparation for the API 570 Piping Inspector certification exam, built against the published Body of Knowledge for February, June and October 2026. The BOK is not one book — it spans eleven documents, and this covers every examinable item in all of them, including the parts it explicitly excludes so that no time is wasted revising them. One part of the exam is open book, so part of the skill is knowing where an answer lives and finding it under time pressure; that is taught here as deliberately as the calculations are. API 570 is awarded by the American Petroleum Institute and nothing here confers it.
Who this path is for
- Candidates sitting the API 570 Piping Inspector certification exam
- Inspectors who know the work and have never sat a code exam under time pressure
- Engineers who can do the calculations but cannot find the clause fast enough
- Anyone who has failed the open-book half while knowing the subject
Module 1
The Exam, and How to Sit It
Closed book against open book and what each half really tests. The effectivity sheet, which decides the editions rather than the BOK. What to bring and how to tab it. Budgeting time across the two parts. Which formulas may be closed book. And the thirty clauses of B31.3 the BOK excludes, so that revision time is not spent on them.
Read
Then practise
Open the effectivity sheet for your exam date and write down the edition of every one of the eleven documents. If any of yours is a different edition, you have found the most expensive mistake available before the exam rather than during it.
Module 2
API 570, the Code Itself
The whole document is examinable. Scope and definitions, the responsibilities of owner-user, inspector and engineer, piping classes and service, condition monitoring locations, injection points, inspection types and their intervals, and the records that have to exist.
Read
- Corrosion loops and piping circuits — the two groupings an RBI study is built onPiping
- Risk-based inspection — deciding what to inspect, and how oftenPiping
Then practise
Tab your copy of API 570 at the clauses this module names, then close it and find three of them again from memory of where they sit. Speed on the familiar clauses is what buys time for the unfamiliar ones.
Module 3
Calculations I — Corrosion, Life and Intervals
Corrosion rates, remaining life and inspection interval, worked in both US customary and SI because the BOK requires both. MAWP of corroded pipe with allowance for the corrosion still to come. These formulas may be closed book, so they are learned rather than looked up.
Read
- Corrosion loops and piping circuits — the two groupings an RBI study is built onPiping
- Running an RBI assessment — from data to an inspection plan that happensPiping
Then practise
Work a remaining-life problem in US customary units, then work the same problem in SI, and check the two answers agree. Candidates who only ever practise in one system lose marks to unit conversion rather than to the subject.
Module 4
Calculations II — Thickness, Pressure and Flanges
Casting and weld joint quality factors and the NDE that raises them. Minimum required thickness and pressure design of straight pipe. Blanks. Hydrostatic and pneumatic test pressure. Impact test exemption and required Charpy values. Preheat and heat treatment. Thermal expansion. And the five flange skills the BOK lists, including choosing the cheapest flange that will do.
Read
- Flanges and pressure classes — why Class 150 is not 150 psiPiping
- Pipe sizes and schedules — why NPS 2 is not 2 inchesPiping
Then practise
Take any flange on a plant you know and establish its working pressure at the design temperature from the tables, then the maximum temperature it could take at the design pressure. Two lookups, opposite directions, and the exam asks both.
Module 5
Welding Qualification Review
Reading a WPS against its PQR and a WPQ against both. Essential and non-essential variables, with supplemental ones explicitly out of scope. Whether the mechanical tests on a PQR are the right ones and whether the results pass. Whether the welder is qualified for the production weld. Within the limits the BOK sets — one process, one filler, P-numbers 1, 3, 4, 5 and 8, no dissimilar metals.
Read
- Reading a WPS and a PQR — what is on the sheet and what the tests provedPiping
- Section IX essential variables — what invalidates a procedure qualificationPiping
- Welder qualification and continuity — the ranges a ticket covers, and the register nobody updatesPiping
Then practise
Take a real WPS and PQR and answer one question only: for each essential variable, does the PQR support the range the WPS claims? That single discipline is most of what this part of the exam asks.
Module 6
API RP 577 — Welding Processes, Inspection and Metallurgy
The entire document is examinable. Processes and their characteristics, consumables, metallurgy and the heat-affected zone, weld discontinuities and their causes, inspection before during and after welding, and the vocabulary the rest of the exam assumes.
Read
- Welding processes, WPS and NDT — what happens before an arc is struckPiping
- Joint preparation and fit-up — the hold point you only get oncePiping
- Preheat and post-weld heat treatment — hydrogen, hardness, and reading the chartPiping
Then practise
List the discontinuities you can name from memory, then compare against the document. The gap is your revision list, and it is usually shorter than people fear.
Module 7
Nondestructive Examination
ASME Section V as the exam uses it — Article 1 general requirements, Article 2 radiography, Article 6 penetrant, Article 7 magnetic particle for yoke and prod only, Article 9 visual, Article 10 leak testing with the bubble test, and Article 23 for ultrasonic thickness. Plus the general NDE rules in B31.3 Chapter VI and in API 570.
Read
- Non-destructive examination — choosing the method and reading the resultPiping
- Examination extent and progressive sampling — what five per cent actually obligesPiping
Then practise
For each of the seven Section V articles, write one line on what it would have you do that you would not otherwise have done. An article you cannot write that line for is one you have read rather than understood.
Module 8
Damage Mechanisms
The fifteen mechanisms from API RP 571 that the BOK names, and the Section 2 definitions. Nothing else from 571 is examinable, which halves the revision most candidates attempt. For each: what causes it, where it appears, what it looks like, and how it is found.
Read
- Material degradation — sensitisation, hardness limits and galvanic attackPiping
- Corrosion control documents — writing down why the plant corrodesPiping
- Integrity operating windows — limits that protect the metal, not the productPiping
Then practise
For each of the fifteen, name the one plant location where you would look for it first. A mechanism you cannot place on a plant is one you will not recognise in a question.
Module 9
Inspection Practice
API RP 574 entire — the components, their inspection and the measurement practice behind the numbers. API RP 576 Sections 5, 6.1 to 6.5 and 7 on pressure-relieving devices. API RP 578 entire on material verification and why PMI exists. And the ASME B16.5 scope the BOK lists.
Read
- Special piping components — the places that do not corrode like the pipePiping
- Relief valve and flare piping — the 3 per cent rule, backpressure and reaction forcePiping
- Pressure test packs and reinstatement — the gate, and what gets put back afterwardsPiping
Then practise
Find out what your own plant's PMI programme actually covers and what it exempts. API 578 is short, examinable in full, and the part candidates skip.
Module 10
Repairs, Alterations and Rerating
The twelve ASME PCC-2 articles the BOK names, each with its appendices — insert plates, full encirclement sleeves, alternatives to PWHT, in-service welding, weld overlay, fillet welded patches, flaw excavation, flange repair, mechanical clamps, pressure testing and NDE in lieu of it. Then repair, alteration and rerating under API 570, and the pressure testing that follows. Closes with the nineteen general practical topics.
Read
- Non-conformance and corrective action — the four dispositions, and why NCRs repeatPiping
- Pressure test packs and reinstatement — the gate, and what gets put back afterwardsPiping
Then practise
Take a repair you have seen and decide which PCC-2 article governs it, then read that article and see whether the repair complied. The exam asks which article applies far more often than it asks what the article says.
Working through this on your own
Read each module's topics in the order listed, then do the practice before moving on. The practice is the part that matters — reading a topic tells you something, applying it to a document in front of you is what makes it stick.
Every topic ends with ten questions. Treat eight out of ten as the bar for moving to the next module.