Pro tip for API 510 Pressure Vessel Inspector Exam

What are you expected to know for the exam?

Before answering this question, we need to know how API 510 Publication Effectivity Sheet (documents identified by API ICP to study for the exam) and Body of Knowledge (what you expected to know for the exam) is selected by API.

API; first identifies a general job description for API 510 inspector. In order to carry the job description assigned to you as an authorized inspector, you are expected to have certain knowledge and experience.

If we categorize API inspectors into 3 levels:

• Apprentice

• Basic Inspector

• Supervising Inspector

Fact: API exam is based on a wide range of topics but the good news is that many exam questions are based on very basic inspection rules. Hence, lots of questions from vocabulary and scope, Organization and Certification Requirements, Types and Definitions of Maintenance Inspections.

Fact: API exam does not want to verify whether the inspector has memorized the codes and RPs, on the other hand, the exam tries to verify whether you have understood the concepts and rules to be able to apply it on various scenarios.

The knowledge type of question comes from understanding codes and recommended practices (Open book questions that you are not expected to remember but should know where to find a particular piece of information, how to interpret and use them for answering a question) while the practical or closed book type of questions come from experience or everyday knowledge that you expected to know by heart.

For API 510 Pressure Vessel Inspector Exam, we have the publication effectivity sheet which tells us that as an Inspector, we should know about:

API 510, Pressure Vessel Inspection Code: In-service Inspection, Rating, Repair, and Alteration. This is a code and tells us about dos and don’ts.

API 510 is based on ASME Section VIII, Rules for Construction of Pressure Vessels, Division 1 which is also a code and hence mandatory.

API 510 code should be read in conjunction with API Recommended Practice 572, Inspection Practices for Pressure Vessels. You can find many similarities between them, especially the vocabulary.

API 572 is a recommended practice or best practice and tell you how to inspect. This is the document that you mostly use during your day to day inspection activities.

Every pressure vessel involves welding and NDT.

For welding you should know about welding methods and processes (API Recommended Practice 577, Welding Processes, Inspection, and Metallurgy) as well as WPS, PQR and WPQ and hence ASME Section IX, Qualification Standard for Welding, Brazing, and Fusing Procedures.

You should know about popular NDT methods (VT, MT, PT, RT, UT) and ASME Section V tell you about how a procedures is written, how often NDT equipment should be calibrated and what should be the qualification of NDT inspectors (cross referenced to ASNT SNT TC 1A).

You should also know about popular corrosion modes and damage and deterioration mechanism and hence selective parts of API Recommended Practice 571, Damage Mechanisms Affecting Fixed Equipment in the Refining Industry.

You should know about how to avoid mix up of material or Positive Material Identification (PMI) and hence API Recommended Practice 578, Material Verification Program for New and Existing Assets.

You should know about pressure relieving devices that any pressure vessel has to vent off during emergency and hence API Recommended Practice 576, Inspection of Pressure-relieving Devices.

And finally you should know about selective Repair of Pressure Equipment such as weld build up and patches, weld insert, exaction and flange repair and hence (ASME) PCC-2,

Let’s look at what type of exam question you should expect from another perspective

API 510 Body of Knowledge not only tells us about the type of questions to expect but also hints at some potential questions:

Fact: API Authorized Pressure Vessel Inspectors must have a broad knowledge base relating to maintenance, inspection, repair, and alteration of pressure vessels.

Fact: Only inspection parts of codes and recommended practices shall be used for exam questions.

You should know about Corrosion Rate and Inspection Intervals. Metal Loss (API 510, 7.4) is definitely an exam question (Open book).

The exam consists of two parts.

The closed-book part tests the candidate on knowledge and tasks requiring everyday working familiarity of API 510 and the applicable reference documents. You shall not have access to codes and RPs during closed book so you should know the answer by heart.

The open-book portion of the exam requires the use of more detailed information that the inspector is expected to be able to find in the documents but would not normally commit to memory.

During the exam, applicants will be expected to choose the best answer from the options provided (multi choice exams) although recently API introduced some 4-5 drag and drop type of questions.

Fact: Definite closed book questions from these API 510 codes sections:

a) Metal Loss (API 510, 7.4)

b) Corrosion Rates (API 510, 7.1)

c) Remaining Corrosion Allowance (API 510, 7.1)

d) Remaining Service Life (API 510, 7.2)

e) Inspection Interval (API 510, Section 6)

Fact: Definite closed book questions from ASME Section VIII codes for weld joint efficiency :

a) Weld Joint Categories (ASME BPVC Section VIII, UW-3);

b) Type of radiography (full, spot, or none) performed basis the nameplate markings (RT-1, RT-2, etc.); (UW-11)

c) Joint efficiency by reading Table UW-12;

d) Joint efficiency for seamless heads and vessels sections per UW-12(d); and

e) Joint efficiency for welded pipe and tubing per UW-12(e).

Fact: Definite closed book questions from these ASME Section VIII codes for static head:

The inspector must be able to compensate for the pressure resulting from static head. All static head will be based upon a Specific Gravity of 1.0. The inspector should be able to:

1. Calculate the static head/pressure conversion factor (0.433 psi/ft) based on Specific Gravity of 1.0

2.  Calculate total pressure (MAWP + static head) on any vessel part;

3. Calculate maximum vessel MAWP given vessel parts MAWP and elevations.

Hence, the reason the pressure gauge should be placed at the highest elevation during the pressure test because it shows the least pressure.

1. The thickness of a cylindrical shell based on circumferential stress given a pressure (UG-27(c)).

2.  Calculate a test pressure compensating for temperature. (UG-99 and UG-100).

3.  Be familiar with all steps in a pneumatic test procedure (UG-100 and UG-102).

4.  The inspector should understand impact testing requirements and procedure (UG-84).

Fact: Definite exam question: Convert a fillet weld throat dimension to leg dimension or vice versa, using conversion factor (0.7).

ASME IX:

Inspector should know about:

• Weld Procedure Specification (WPS)

• Procedure Qualification Record (PQR)

• Welder Performance Qualification (WPQ)

1. a) Essential and non-essential variables. (Supplementary essential variables in case of PWHT).

2. b) Number and type of mechanical tests for PQR, and acceptable results.

3. d) Welder is qualified in terms of weld thickness and welding position.

Fact: Definite exam question: PQR and WPQ must be certified by signing and dating.

Fact: Definite exam question: Any rules in API 510 shall take precedence over ASME Section VIII.

Fact: Definite exam question: Study API 510 and API 572 vocabulary very carefully. Lots of basic questions.

ASME Section V, Non-destructive Examination:

You should know about NDT examiner qualification, instrument calibration and what comes in a typical NDT procedure and report for RT, MT, PT and UT (thickness measurement only) methods.

General Practical Knowledge (Closed book):

• Organization and API 510 Certification Requirements.

• Types and Definitions of Maintenance Inspections.

• Pressure Vessel Materials and Fabrication Problems.

• Welding on Pressure Vessels.

• General Knowledge of NDT Methods.

• Pressure Relief Devices.

• Maintenance Inspection Safety Practices.

• Inspection Records and Reports.

• Difference between Repair and Alteration.

• Rerating Pressure Vessels.

• Pressure Testing after Repairs, Alterations, or Rerating (When mandatory, who decides)

Potential exam questions from ASME PCC-2, Repair of Pressure Equipment

Article 201: Butt-Welded Insert Plates in Pressure Components

Article 202: External Weld Build up to Repair Internal Thinning

Article 209: Alternatives to Post Weld Heat Treatment

Article 210: In-Service Welding

Article 211: Weld Build up, Weld Overlay, and Clad Restoration

Article 212: Fillet Welded Patches

Article 216: Welded Hot Taps in Pressure Equipment or Pipelines

Article 304: Flaw Excavation and Weld Repair

Article 305: Flange Repair and Conversion

Article 501: Pressure and Tightness of Piping and Equipment

Article 502: Non-destructive Examination in Lieu of Pressure Testing for Repairs and Alternations