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