In this module, you shall learn about:

• • How to apply for API 653 exam,

• • What you shall expect during exam day,

• • Time management during the examination &

• • Some exam tips.

Basic Facts

What you should expect during Exam Day?

API Exam Day at the prometric test center

How the API exam questions developed? 

Periodically a question writing session is conducted.  Subject Matter Experts (SME’s), or individuals who specialize in pressure vessels, write questions from specific sections of the Code.  Each question is then checked by three other SME’s.

This validation exercise addresses two issues:

1. Is the question written clearly?
2. Does the question cover knowledge that is important to the inspector?

These questions are initially included in the question databank as non-scored pretest questions.

Presently there are over 1000 scored questions in the databank and are grouped by topics.

For each examination, there are 170 questions on the exam, of which only 140 are scored and 30 pretest or experimental questions that are not scored.

The scored non-scored questions are unmarked; that is; shuffled together. Hence, you have to answer all 170 questions.

Out of 170 questions, 110 questions are in closed-book part of the exam, and 60 questions are in open-book part.

How to prioritize and plan studying for API 653?

You have only a limited amount of time to study, so you need to invest your time wisely, that is, obviously, you should spend your study time where you can get the MAXIMUM return!

Almost half of the test questions come directly from API 653.  So that’s your priority!

For every hour spent on the other publications, spend 2 hours studying API 653.

If you thoroughly understand API 653 and don’t even look at the other publications, chances are, you could pass the test based on your personal knowledge of other codes and recommended practices.  (We are not recommending this approach!)  But remember, almost half of API exam questions comes straight from API 653 Inspection Code.

There will be about 70-75 test questions directly from API 653.

API 653 is about 150 pages long. This is an average of one question for every two page.

The remaining 85-90 questions will come from some 2000 pages contained in the other documents.  That’s less than 1 question for every 20 pages read.

Spend your time mining in the rich veins of API 653.  To do well in the exam, you must “Major on the Majors, and Minor on the Minors”.  For this exam, API 653 is the “Majors”!

Our level of coverage of subjects directly depends on the average number of questions you may expect during the exam.

This means, we shall cover briefly those refence materials that contribute to a few exam questions while question rich reference materials are covered in much more detail. Need to know basis.

Time Commitment

Time is your limited resource.  Your learning efficiency will increase by having a plan and be focused.

Why spend hundreds of hours studying haphazardly when you could learn just as much or even more with 50 hours of organized approach?

Our e-learning course helps you manage your time as well as focusing on key subjects in an organized and effective manner.

The plan can be based on 12 weeks of preparation with 6 – 8 hours of study each week.

This plan will allow you to study at a steady pace whenever you want and wherever you want with 24/7 access to our e-learning course and a WhatsApp chatline to answer your questions, if any.

Your learning and satisfaction will significantly increase with this disciplined approach that can also fit in with your daily routine.

Do not wait and cram the week prior to exam.  You may still be lucky to pass the test, but you will soon forget what little you have learned.

Preparing for a certification exams is a great opportunity to really increase your inspection knowledge and skills.

Make the most of it by significantly enhancing your career by getting certified.

How the questions are set?

The examination has two sections:  open book and closed book parts.

• The API 653 exam day is 7.5 hours long – a short tutorial session, 2.75 hours for the closed-book portion, a 45-minute lunch break and 3.75 hours for the open-book portion.

The closed-book examination includes such questions which the inspector is normally expected to know without referring to the Codes. These questions are called “awareness” type or ”practical” type of questions.

Whenever you find a very definitive or quantitative statement or fact in body of the Code, a closed book question may be expected on it.

Thus, the basic requirements of a code, specific “DO” and “DON’T” statements, important quantified statements, important definitions and well-known inspection principles will constitute a closed book question.

Where the candidate is required to refer to the diagrams or formulas or tables or graphs and curves from the Codes, it will always be an “open-book” question.

All calculation type of questions will normally be “open-book” type.

The information in the Code, which is not short and crisp, (that is, large paragraphs, several descriptive statements clubbed together) will normally be asked in “open-book” part.

Here, the candidate is expected not to remember the information but should know where to find it in the body of the Code. Navigating through codes and RPs during open book exam is important especially since the search button is disabled during the exam.

The questions asked in closed book part are straight forward statements directly taken form Code without much of the modifications and therefore are easy to answer.

Pay special attention to relevant figures, charts and table footnotes.

To answer open-book questions, one only needs to know where to find the answer in the code. If you cannot find the information quickly, go to the table of content. I f you still cannot find it, go to list of tables and figures.

We shall highlight important pages of codes in each module.

During mock exam practice sessions, please use codes and RPs especially for calculation type of sample and mock exams and actually solve them yourself even though it may look very simple.

Frequenting codes and RPs would help you greatly during open book part of the exam and saves time.

Please note that it is very important to also work with the soft copy of PDF version of the codes and RPs as it is quite different when you go through a hard copy or any other medium of a code than when you go through the PDF format.

You should get used to navigating through the PDF version as this is the medium you have to work through during the examination without using ”word search” capability.

Please remember that study of API 653 code has to be “thorough” and total, while study of ASME Sec. V and ASME Sec. IX should be such that it covers the topics mentioned in the “Body of Knowledge”.

Our E-leaning modules is specifically focused on the body of knowledge.

• • If you are about a month away from examination, read all the Codes at least once and concentrate on highlighted text in the Codes.

• • If you are about two weeks away from the exam, concentrate on highlighted text as well as the mock examinations provided.

• • In the last week of preparation, focus on Flash Cards and highlighted text from the codes and RP.

Time Management during the Exam

Closed-book part of the exam (110 questions) can be finished within 2 to 2 ½ hours, against the allotted 2.75 hours.

While “open-book” part (60 questions) takes a little longer and may require all the 3.75 hours that are allocated depending on how fast you can find the relevant topic within the reference documents.

Always keep a tab of the clock on the right-hand top corner of the computer screen. It shows the remaining time versus number of questions answered.

For closed book, you have an average of 1.5 minutes per question for closed book part and 3.75 minutes per question for open book.

This means you should answer 40 questions per hour for open book part and some 16 questions for closed book part as a minimum.

You can end the tutorial session earlier whenever you feel comfortable enough working with the icons.  The exam would automatically start after the 10 minutes allocated time for tutorial or if you end it earlier.  The icons are simple and user friendly.

Remember that you can flag off those questions you are not sure of so you can return back to them during the remaining time.

You can also right click on selected answers to eliminate them if you are confident that they are definitely the wrong answers. This will narrow down the possible right answers and therefore increases you chance of getting the right answer.

You can either review all the questions once again or review the flagged off questions or review incomplete questions (questions you have not attempted) by clicking on respective tabs during any remaining time left.

The exam ends automatically when the remaining time showing on the right-hand corner of the screen reaches zero.

No Negative Marking

The pass mark is roughly 70% (Minimum 400 on a scale of Maximum 500) for all the API examinations as API uses scaled grading to standardize the degree of difficulty for all the exams.

No negative marking is applied.

Therefore, it is recommended to answer all the questions.

At the end, click the ‘’review all’’ button and peruse through the list to ensure that you have not skipped any question.

You can also check ‘’review incomplete questions’’ to ensure there is nothing on the list, that is, no question left unanswered.

API 653 Exam sequence

API core examinations contain two parts (Closed & Open Book).

First, you would answer the closed book part (2 hours 45 minutes for some 110 questions).

After that, you have a maximum of 45 minutes break when you can leave the building and also use the locker.

After the break, you would start the second part (open book) and need to answer some 60 question within 3.75 hours of allocated time using the reference documents in PDF format available on the computer screen.

The ‘’word search’’ is disabled so you should know which document and also which section you should look for each question.

In subsequent modules, we shall explain how you could navigate between documents to find the right answer, chart or formulae you need to solve an open book exam question.

45 Minute Exam Break between Closed & Open Book 

Remember that the open book or second part of the API core examinations automatically starts after the 45 minutes break or if you start the second part sooner by pressing the ‘end the break’ button.

This means you should start your second part of examination (open book part) no later than 45 minutes after completing the first part in order not to lose any time.

Try to report to the examination center around 5 minutes before the end of the 45 minutes break to allow for time spent going through the security check and sign in.

During API 570 examinations, one of our candidates went for lunch and returned half an hour late. By the time, he started his second part of the exam; he was already some 30 minutes short of the allocated 3.75 hours because after the 45 minute break, the time for second part of the test (closed book) keeps running regardless of whether you are at your desk or not.

Tips on Time Management during exam

Remember, if you need to leave the examination room for say, using the toilet or drinking water, you need to take your ID with you, report to the security outside the examination room and sign out. On return, you shall go through the same initial security check and sign in. During all this time, the clock is running.

Remember, your exam is not concluded until your time is up or when you press the ‘end exam’ button (which asks for confirmation to ensure that you have not pressed it accidentally).

You can also see the list of attempted and non attempted questions by pressing the ‘’review all’’ button. This would ensure that you have not left a question unanswered. You can see the remaining time at the upper right hand corner of the screen. There are a few good tutorials in the API ICP (Individual Certification Program) website.

The allocated time seems to be more than enough to answer all the questions as well as review them.

Number of Exam Questions

There are 170 questions in the core exams, of which only 140 are scored.

The remaining 30 are pre-test questions and not marked towards your score, meaning these pre-test questions do not affect your score whether you have answered them correctly or incorrectly. API does not tell you which ones these questions are.

The reason for these non scored pre-test questions is that API frequently adds up new questions to their existing question bank.

API needs to ensure that these questions are not significantly challenged by the candidates and also answered by a reasonable number of people before adding them to their question bank as scored questions.

Exam Result

API Exam comes with Instant Final Scoring now

As of April 2024; all candidates appearing for API exam shall receive instant confirmed scoring and maximum within 24 hours after exam from prometric.

That is not all.

Candidates shall also receive their downloadable certificate in their API account within 3 days.

This is a huge difference of previously waiting for final score for upto 8 weeks and another 8 weeks to receive your certificate. To read more, click on link:

Instant Scoring

If you fail, you need to apply for rescheduling and pay USD 350 $. You shall receive the exam authorization approval email normally within 2-3 working days. You shall then book your seat with the Prometric as soon as possible.

Certification & Recertification; and Cost

API 653 certification is valid for a three-year term and cost USD 1,055 $.

After 3 years, you need to apply for recertification demonstrating that you still work as an API 653 inspector for 20% of the time. Recertification cost USD 830 $.

You may apply for recertification 90 days prior to the certification expiration date, and for a 90-day grace period after. If an application is not submitted by the end of the 90-day grace period, the certification will expire. A new application and the full fee must be submitted, and you will need to pass the full version of the examination in order to be recertified.

Late application fee for both new certification and recertification is 150 $.

API inspectors are required to take an on-line, open-book quiz every six years in order to recertify. Each quiz has 25 questions that address the changes in the relevant API codes over the past six years. You have a total of four hours to complete the quiz, and it may be paused or interrupted up to three times.

If you fail the quiz once, you will be able to take it again. If you fail the quiz a second time, you will not be able to recertify. You will need to submit a new application and take the full version of the exam to certify again.

Publications Effectivity Sheet & Body of knowledge

Publications effectivity sheet is the list of applicable reference documents that you need to study for the exam. It also tells you which sections of each document are applicable. It can be revised from time to time when the codes and recommended practices or their addendum are revised and becomes applicable. Red color-coded texts indicate a revision or a change from the previous Publication Effectivity Sheet.

Body of knowledge also list the reference codes and recommended practices (but without revision number) and elaborates on topics that a storage tank inspector needs to know giving examples. It shows what you are expected to know.

Our e-learning is particularly designed around the reference documents and the body of knowledge.

Area of examination scores

Below please find a sample score sheet showing the maximum number of score you could achieve for each area. This should give you a fair idea of importance and weightage of each area of knowledge.

  Content Area                                          Maximum Score

Scope and General Application of 653                               5

Corrosion Mitigation                                                                 15

Repairs                                                                                              15

NDE                                                                                                      15

Welding                                                                                                 15

Design                                                                                                   10

Planning                                                                                              20

Inspection and Testing Practices                                              15

Data Evaluation                                                                              24

Roles and Responsibilities                                                          6

Total Score                                                                                      140

Click to go to: 

All you need to know about API 653 Storage Tank Inspector Exam – YouTube

API 653 Storage Tank Inspector Training Course Introduction – YouTube

API 653 Storage Tank Inspector Examination – Basic Facts – Part 1 – YouTube

API 653 Storage Tank Inspector Examination – Basic Facts – Part 2 – YouTube

Exam Tips