What to study to pass the api 653 examination

By Carlos F Molina

Choosing to read this article is choosing to begin the path to API certifications. The most important objective of apiexam.com is to give affordable, safe learning advice in order for you to pass the API certification examinations, beginning now, and not having to make the course and spend the bunch of money it costs.

The way I see it, if you already decided you want to try certification, you have 4 options.

Study on your own beforehand, don´t take the course then take the exam

Not recommended. Maybe you are one of those people that can read English very well, and are used to taking and passing tests of all kinds.  However, have in mind that there are several differences and correlations between API 650 and 653 that are not so clear to see, so you will need someone´s guide to really understand what you are studying

Study on your own beforehand, then take the course then take the exam

This is highly recommended, especially if you are already using the standards on a daily basis, if you have experience in the field or any certification in welding or NDE.

Don´t study beforehand, then take the course then take the exam

Not recommended if you are not using the standards on a daily basis. As you know, learning is a lot easier when you build up new concepts above old concepts you have. However, Is not just knowing and not studying, given that standards are of changing nature. I know several people that are experts in the field of tanks, but as they are not used to taking tests, or they don´t understand English well, so they flunk the exam.

Take the course and don´t take the exam

This is a big mistake. Ideally, you should try to take the exam immediately after you have taken the course, so the concepts are still “hot” in your mind. The craziest mistake you can make is taking the course and not the exam, because, let´s face it, it is certification what we are talking about. Certification opens new doors. Taking the course and flunking is not precisely comfortable to say.

So what is this website for? To give students a possibility to have contact with the standards on a daily basis, by means of Questions and Answers, Exercises, Examples, Animations, etc. My aim here is to make it so good that you won´t even have to take the course. Are you up to it?

This is what you should learn from API 653 in order to pass the exam


API regularly launches a Body Of Knowledge (BOK), that summarizes the core teachings, concepts, and essential competencies that need to be mastered by new inspectors to receive certification. API 653´s body of knowledge is dynamic, since every year it incorporates new information and techniques. The current Body Of Knowledge was updated as of October 2013.

According to the current BOK, to be a successful inspector you will need to know the following:

  How to evaluate corrosion rates and inspection intervals
  Establish joint efficiencies
  Calculate maximum Fill Height for an Hydrostatic test
  Determining the sizes and spacing of welds for shell openings
  Determining requirements for Hot Tapping
  Settlement evaluation
  Number of settlement points
  Impact Testing
  Calculate minimum thickness of tank shell
  Calculate minimum thickness of tank shell for reconstructed tanks
  Determine if a tank shell corroded area is acceptable for continued service
  Evaluate a pitted area
  Calculate dimensions for replacement plates
  Calculate dimensions for lap welded patch plates
  Ensure you can proficiently review a PQR and a WPS and determine it’s conformance to Sec IX
API 650 AND 653
  General welding requirements
  Be familiar with and understand NDE applied to tank repair and construction
API 650 AND 653
  General NDE requirements
  API RP 571, Damage Mechanisms Affecting Fixed equipment in the Refining Industry
  API Recommended Practice 575, Inspection of Atmospheric and Low-Pressure Storage Tanks
  API RP 577, Welding Inspection and Metallurgy
  API Standard 653, Tank Inspection, Repair, Alteration, and Reconstruction and the relatedportions of API Standard 650, Welded Steel Tanks for Oil Storage
  API Recommended Practice 651, Cathodic Protection of Aboveground Petroleum StorageTanks s
  API Recommended Practice 652, Lining of Aboveground Petroleum Storage Tank Bottom

Just study that, and you should do fine


Since 2012, there is a change in the way the exam is being held. Before that, you would go to a Prometrics place with your hard copy standards that would be checked and take a paper written exam. But now, the exam is administered via a computer in a Prometric´s testing center.( That means that you will save some dollars on standards)

The examination consists of two parts. The closed book part tests the candidate on knowledge and tasks requiring everyday working knowledge of API Standard 653 and the applicable reference documents. The open book portion of the examination requires the use of more detailed information that the inspector is expected to be able to find in the documents, but would not normally be committed to memory.

There are 150 questions on the exam, of which only 125 are scored. The remaining 25 are pretest questions.    The exam day is 8.5 hours long, and includes 3 hours for the closed-book section, 4 hours for the open-book section, a half-hour tutorial session, and a 1-hour lunch break.

Papers and books are not allowed in Prometric’s computer testing centers.  All materials needed for the open-book portion of the exam will be displayed on your computer screen in English.

One final tought


In some websites advertising training courses, they rest importance to memory as an important tool in learning technical subjects lie standards and standards. I think they are wrong, because you learn mostly building above what you already know. There is no learning without memorization. In fact, the Body Of Knowledge states clearly that the fact that there is an open book and a closed book parts is because while there are some facts you need to use daily (closed book), so there are things that you won´t remember easily without opoening the book.

With that in mind, I never discourage anyone to learn trough flash cards if they feel is the best option for them. If you keep coming back to API exam, you will see how we use flash cards and other tools to make study of API 650 and 653 very dynamic.

Again I thank you dearly for your support and the success of apiexam.com. Thank you, and good luck! Cheers!

Introduction to the API 653 Certification Exam

By Carlos F Molina

With this post I am announcing the birth of APIEXAM.COM, a website dedicated to deliver resources to pass the certification examinations of the Individual Certification Programs of the American Petroleum Institute. It is a compendium of the subject that will grow while I study for the exams. For the time being, you will see plain posts about the subject in a blog format, but the idea is that with your help we will be improving the site and increase resources. Welcome.


If you read the first chapter of API 653, you will see it is a standard that covers Inspection, Repair, Alteration, and Reconstruction of steel storage tanks built to API 650 and its predecessor, API 12C. It provides minimum requirements for maintaining the integrity of such tanks after they have been placed in service and addresses inspection, repair, alteration, relocation, and reconstruction.

API Standard 653, “Tank Inspection, Repair, Alteration, and Reconstruction,” was first published in January 1991, and is one of 11 standards of inspection that make part of the Individual Certification Programs of the American Petroleum Institute (API). It provides a certification which evaluates the knowledge and experience of technical and inspection personnel involved in tank inspections.

The scope of API 653 is limited to the tank foundation, bottom, shell, structure, roof, attached appurtenances, and nozzles to the face of the first flange, first threaded joint, or first welding-end connection. It means that if you look in API653 for inspection guidelines regarding dikes or even types of foundations, you won´t find them. However, as an inspector you should be able to deliver a report about them in case of need.

Many of the design, welding, examination, and material requirements of API 650 can be applied in the maintenance inspection, rating, repair, and alteration of in-service tanks. In the case of conflicts between the requirements of API 653 and API 650, API 653 shall govern for tanks that have been placed in service. API 653 should be followed over API 650 when we are treating tanks repair and reconstruction.

API 653 standard employs the principles of API 650; however, storage tank owner/operators, based on consideration of specific construction and operating details, may apply this standard to any steel tank constructed in accordance with a tank specification. Is understandable then that an API 653 certified inspector should be completely knowledgeable about API 650.

Api 653 standard does not contain rules or guidelines to cover all the varied conditions which may occur in an existing tank. When design and construction details are not given, and are not available in the as-built standard, details that will provide a level of integrity equal to the level provided by the current edition of API 650 must be used.


API’s certifications have come to be regarded as the most demanded and desired credentials in the industry. They provide applicants with means to improve their skills through learning and strengthening their overall job performance. API certified inspectors and personnel are recognized worldwide as professionals who are fully knowledgeable of the relevant industry inspection codes and standards, and who are capable of performing their jobs in accordance with the latest and most acceptable industry inspection practices.
API certification allows qualified personnel to establish a career path and make valuable contributions to the safety and quality of industry operations. Here are 4 reasons to become certified

  1. API has instant name recognition.When you become certified, you join a growing group of some 30.000 professionals worldwide who have become API certified. The popularity of API usually means respect in your field.
  2. Inspection industry is growing.Your API credential will help you stand out from the competition for inspections projects in a tough market, especially in this rapidly expanding new sector of the economy. New projects are decreasing while maintenance ones are increasing. This kind of professional will be needed.
  3. API has become an industry standard.Many employers in the oil industry expect job candidates to have API certifications. It is no longer an exception; it is the norm.
  4. Your employer may pay for you to take the exam.Recognizing the value of a API trained workforce, many companies in the oil industry will pay for the course, exam and accreditation fees for their employees. In other words: your boss will approve, and it might be free!


Can you use API 653 to inspect an horizontal tank resting on saddles?

Horizontal tanks that rest in saddles, weren´t built to API 650 nor API 12C. However, I you can´t find a standard for the tank you are inspecting, API 653 provides a little help when it says “This standard employs the principles of API 650; however, storage tank owner/operators, based on consideration of specific construction and operating details, may apply this standard to any steel tank constructed in accordance with a tank specification”. Good engineering judgment should be the rule


You have a tank designed in 1990 that needs to be repaired. It should be repaired as per older edition by which it was designed or current edition of API 650?

The answer lies in 3.2, when it says “The standard used for repairs or alterations made after original construction is the as-built standard only for those repairs or alterations, so there may be more than one as-built standard for a tank”. So API 653 allows to use several editions according to your engineering judgment. If we were to use always the latest edition, that would increase total repair costs.

Cheers, and I look forward to your thoughts and comments