How the 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 answers two questions.
- Is the question written clearly?
- Does the question cover knowledge that is important to a vessel inspector?
These questions then go into a question databank as non-scored exam question.
Presently there are over 1000 questions in the databank and are grouped by topics. For each examination, there are 170 questions on the exam pulled in specified proportion from various categories. Only 140 Questions 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.
API needs to ensure that these questions are not significantly challenged by the candidates and also has been answered by a reasonable number of people before adding them to their question bank as scored questions.
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 texts indicate a revision or a change from the previous API Effectivity Sheet.
Body of knowledge also list the reference codes and recommended practices (without revision number) and elaborates on topics that a pressure vessel inspector needs to know giving examples. It shows what you are expected to know.
From time to time, API conducts a Job Analysis to re-evaluate the API 510 exam to ensure that it remains relevant and continues to focus on the inspectors’ core competencies. As a part of this process, the publication effectivity sheet and body of knowledge is revised. For example, API 510 Publications Effectivity Sheet applicable for exams held between September 2022, January 2023, and May 2023.
Number of Exam Questions per Code and RP
As per Effectivity Sheet for API-510 exam, there are 4 codes (API 510 code & ASME Codes V, VIII & IX) and 4 Recommended Practices (RP) prescribed for examination.
However, all of them are not equally important and therefore, do not require equal emphasis.
About 40% of questions are asked from API 510 code which is some 60 pages long, while the rest contribute to remaining 60% which are 2000 pages long.
| Code | Approximate Percentage of Questions |
| API 510 Code & API 572 | 50 – 51 |
| ASME Sec. Vlll Div.1 | 8 – 10 |
| ASME Sec. IX & API 577 | 8 – 10 |
| ASME Sec. V | 8 – 10 |
| API RP 571 | 5 – 6 |
| API RP 576 & 578 | 5 – 6 |
| PCC-2 | 5- 6 |
| Gen. Knowledge | 3-4 |
Below table shows area of examination versus maximum number of exam questions and should give you a fair idea of how important each part of Body of Knowledge is.
Area of Examination Maximum No. of Questions
Scope and General Application of 510 5
Damage Mechanisms 15
Repairs 15
NDE 15
(Procedures, limitations, advantages, techniques, responsibilities, applications)
Welding 15
Design 10
Planning 20
Inspection and Testing Practices 15
Pressure Relief Devices 4
Data Evaluation 20
Roles and Responsibilities 6
Total Score 140
Add another 30 non scored questions that are distributed across the topics.
No Negative Marking
The pass mark is roughly 70% for all the API examinations. No negative marking is applied. Therefore, make sure that you have answered 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.
