For tank inspectors sitting API 653
API 653 course and practice exams
Practice shell, bottom and settlement calculations on the two-part API 653 clock.
Plans and prices
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- 8 modules of lessons with worked examples
- 2 timed exams at real length: 170 questions, 390 minutes
- 26 drills on finding the right section in API 653 fast
Lifetime access, including your retake
Not ready? Try the free 10-question check
Other options
Have my manager pay instead
Everything in API 653 course
Learn every Body of Knowledge section, work the tank calculations step by step, then prove it on timed exams.
- 8 lesson modules covering every task in API's API 653 outline
- 12 worked calculations you can repeat with your own numbers
- A week-by-week study plan built from your free check and exam date
- 347 original questions, each explained with the reference it uses
- 2 full-length timed exams (170 questions, 390 minutes), weighted like the real exam
- After each timed exam, see how each domain moved since your last one
- Domain scores after every drill show what to study next
- Exam-day checklist: what to bring, allowed references and the calculator rules
- 26 drills on finding the right section in your own API 653
- Today's 10: ten a day, and every miss comes back until you get it right
- Listen to Today's 10 on the go
- Readiness by domain, from your own practice results
- Every question, reshuffled into new sets aimed at your weakest domain
- Flashcards for every domain, with spaced review
- Patch, your AI study assistant
Best if: You want a structured path through the whole API 653 Body of Knowledge.
What's covered
- API 653: scope, the inspector, inspection types and records
- Corrosion rates, remaining life, inspection intervals and joint efficiency
- Shell evaluation: minimum thickness, fill height, corroded areas and pits
- Bottoms, foundations, settlement, cathodic protection and linings
- Repairs, alterations, reconstruction and testing
- Welding: procedures, welder qualification and the tank welding rules
- Nondestructive examination: ASME V and API 650
- Damage mechanisms, brittle fracture, tank condition and relief devices
In API 653 course
- 347original questions
- 2timed exams at real length
- 8modules of lessons
- 26code-finding drills
See how Patch answers
Working out a corrosion rate
A wall reads 0.500 inch, then 0.480 inch four years later. What is the corrosion rate?
You: How do I get a corrosion rate from two thickness readings?
Patch: Subtract the later reading from the earlier one to get the metal lost, then divide by the years between the readings. Losing 0.020 inch over 4 years is 0.005 inch a year.
Key point: Corrosion rate is metal lost divided by the time between readings.
An original example, not an exam question. AI can be wrong, so check it against your course.
What members get
With the course.
Today's 10 10 questions a day from your misses and your weakest domain, so what you got wrong comes back. Plus a missed set of up to 50.
A plan to your exam date Set your date and get a week-by-week plan you can add to your calendar in one tap.
Readiness by domain Your practice results against a 75% study target, and how they moved this week. A study target, not a pass prediction.
- Timed exams on the real clock. A live pace line, and Save and exit when you need a break. You pick up with the time you had left.
- An exam-day guide. What to bring, the references you may use and the calculator rules.
- 347 original questions, every one explained. Review every miss after each timed exam. Practice sets show you the ones you haven't seen first.
- Wrong answer key? We fix it within 2 business days and log it publicly.
- One payment. No subscription, nothing renews.
- Didn't pass? Every plan except the 7-day pass has lifetime access. Your retake prep is already paid for.
Practice drawn to the API 653 outline: every domain at its exam weight
- Calculations and tabular evaluations for thickness measurements, weld sizes and tank integrity25%
- Welding on atmospheric aboveground storage tanks15%
- Nondestructive examination15%
- Practical knowledge - general20%
- Practical knowledge - specific25%
See the numbers
Each domain's weight on the API 653 outline, as our timed exams draw it, beside its share of the 347-question bank.
| Domain | Outline | Bank |
|---|---|---|
| Calculations and tabular evaluations for thickness measurements, weld sizes and tank integrity | 25% | 25% |
| Welding on atmospheric aboveground storage tanks | 15% | 15% |
| Nondestructive examination | 15% | 15% |
| Practical knowledge - general | 20% | 20% |
| Practical knowledge - specific | 25% | 25% |
Next API 653 window: Mar 2027. API's application deadline is 7 Jan 2027.
Instant access. Everything in the plan you choose opens as soon as checkout completes.
See the teaching before you buyRead a complete lesson from the course, “Corrosion rates, remaining life, inspection intervals and joint efficiency”, and try a short practice set with full explanations. Free, no signup.
Read the free lessonWhat the course covers
8 modules covering every task in the API 653 outline.
- API 653: scope, the inspector, inspection types and records (5 sections)
- Corrosion rates, remaining life, inspection intervals and joint efficiency (4 sections)
- Shell evaluation: minimum thickness, fill height, corroded areas and pits (5 sections)
- Bottoms, foundations, settlement, cathodic protection and linings (5 sections)
- Repairs, alterations, reconstruction and testing (5 sections)
- Welding: procedures, welder qualification and the tank welding rules (6 sections)
- Nondestructive examination: ASME V and API 650 (6 sections)
- Damage mechanisms, brittle fracture, tank condition and relief devices (5 sections)
Questions
When do I get access?
Straight away. Checkout takes you to your course, and the receipt email has the same link.
How do I get back into my course?
Use the link in your receipt email. If you can't find it, enter your email on the course page and we resend it to the address on your order.
Is 347 questions enough?
Each one comes with a worked explanation and its reference. You also get 24 end-of-module checks, 26 code-finding drills and 12 worked calculations. Today's 10 and your missed set bring your misses back on later days, so you work the bank instead of reading it once.
Can I get a refund?
Eligibility depends on your plan, when you request a refund and your paid use. See the refund terms for the conditions and exceptions.
What if I need a retest?
Keep studying in the same course. Your access has no end date, so your retake prep is already paid for, and your practice history, missed questions and readiness by domain are still there. The 7-day pass is the exception: it ends after 7 days.
How long do I keep access?
Lifetime access: your access has no end date. Updates are included, so if American Petroleum Institute moves this exam to a newer code edition while you have access, your course moves with it. The 7-day pass is the exception. 7-day pass: access ends 7 days after payment, to the minute. It does not renew and is not a subscription. A timed practice exam started before then can still be finished.
More questions (7)
If I buy the 7-day pass now, is its price taken off a bigger plan later?
No. Each plan is a separate purchase at its listed price, and the $39 paid for the 7-day pass is not credited toward another plan. With more than a week before your exam, a full plan is the better buy.
Are the questions copied from the exam?
No. Every question is original and written to American Petroleum Institute's published content outline. Exam content is confidential and we never use it. We are not affiliated with or endorsed by American Petroleum Institute.
How are the questions written?
In our own words, to API's current published outline. See how many questions cover each domain.
Do I need my own copy of API 653?
No. In the open-book part of the exam, API shows only the sections of the publications on its Publications Effectivity Sheet on your screen as PDFs, and papers, notes and books are not allowed in the testing center. A copy of those publications is still useful for practice, so you can find your way around them before the clock starts. We cite sections by number and never reproduce the text of any API or ASME document. Check the sheet for your exam date.
Can my employer pay?
Yes. Pay at checkout and we email a receipt you can expense, or download a reimbursement request to send your manager.
Is Patch AI?
Yes. Patch is an AI study assistant, not a person or an instructor. Check important details against your lessons and references.
Can you promise I will pass?
No, and nobody honest can. We promise everything listed in your plan, and a fix within 2 business days for any wrong answer key.
Employer paying?
Many employers fund API 653 prep. Generate a reimbursement request PDF to send to your manager. Buying for a crew? Request a quote