Area of Examination & Reference Documents
In this module, you shall learn about:
Reference documents,
In this module, you shall learn about:
Certified API 653 Aboveground Storage Tank Inspector must have a broad knowledge in tank inspection and repair of aboveground storage tanks.
In a nutshell, an API 653 Aboveground Storage Tank Inspector should know about:
The API 653 examination has two sets of references as study materials:
One set contains ASME codes (Section IX- Welding and Section V-Non-destructive Testing) and API Standards (API 650 and 653).
The other set of reference materials are API Recommended Practices (API 571, 575, 576, 577, 651 & 652).
Most of calculation type of questions from the API standard and ASME codes are in the open book part of the examination.
You need not memorize the formulas but should know where to look for when solving the open book questions. This is especially important since the search button is disabled during the exam.
If you cannot find what you are look for during the open book exam, look at the table of contents.
Still, can’t find it? Look for list of tables and figures.
Still can’t find it, make a note of question number, flag it off and jump to the next questions. Chances are you may find it later when looking for answer to other question.
Never spend more than 2 minutes looking for an answer in the open book question, otherwise you may be short of time answering all questions.
You should have an idea how to navigate through them during open book part.
When reading a code and standard; donāt immediately dive into the details.Ā Get the bigger picture.
First, understand what the code covers by reviewing the opening paragraphs of each code. This is called the Scope or purpose.
Next, look at the table of contents to understand how the code is structured. It helps you to have a fair idea of where to look for.
List of figures and table of contents can be used as plan āāBāā if you cannot find a particular piece of information from the content list.
This step is often overlooked: the purpose of the code and how to locate the information.
We have flagged important pages of codes within each summary and also brought important information in the flash cards. These information are potential exam questions.
Our mock exams and quizzes also designed to test your knowledge, help you understand how to interpret and check if you missed something we explained before.
Those closed book exam questions that are coming straight from API and ASME codes; are the ones that an inspector would be using on daily basis and therefore, you need to memorize them. API calls them āāpractical questionsāā.
But donāt worry; we shall supply you with enough presentation, mock question and flash cards to ensure that you would not forget them during the exam.
We have summarized the second set of reference documents contain the recommended practices (API 571, 575, 576, 577, 651 & 652); highlighted important information and explained the underlying reasons whenever necessary, so you can understand the concepts.
Please note that only API 650 & API 653 are standardsĀ and hence are mandatory, while the rest of API documents are recommended practices (good engineering practice).
Closed book questions mostly come from API 653 standard and RPs because these information are supposed to be used by inspectors on daily basis.
For open book questions that need referring to tables, graphs and formulas, you shall have access to both the API RPs and API 653 code as well as the ASME codes.
We shall cover them within the next 9 modules combined with flash cards and mock exams
Note: A Code document is mandatory and cannot be violated while a Recommended Practice;Ā as the name suggest, is a recommendation which means you can deviate from it based on circumstances and based on sound engineering judgement.
[/vc_column_text]Codes are based on scientific conclusions while recommended practices are mostly the result of past experience gathered over the years showing the trends and good practices. Thatās why; you may observe that the formulas brought within RPs are empirical. The empirical formulas have no sound scientific backing and are merely formulated to show the trends and relationship between various parameters.
Why? Because, to turn an empirical formula into a scientific formula necessitates including many more parameters of less importance and this would unnecessary complicate the equation where as empirical formulas are like rule of thumbs and can be of everyday use especially when you do not need to be that accurate.
The analogy would be the difference between a WPS and a Welding Instruction. The welder does not need to know about all the essential and non essential parameters or the PQR and itās associated test reports. All the welder needs to know is the range of amperage & voltage, the welding speed, the type and size of electrode, the welding position, the number of passes and if any pre heat required.
Empirical formulas are used when a very high accuracy is not important. They are basically the mathematical representation of trends. For example, as a rule of thumb, you need to preheat 4āā or 4t from each side of the weld whichever is more. You do not really need complicated formulas to come to the right number that you cannot even implement in practice.
Scientific formulas accurately explain the phenomena for all the ranges of parameters while an empirical formula only works within a limited range.
Overall, the Codes are scientific based while RPs are more experience based.
Before going to the relevant section, you need to know which document or documents you need to look at in order to find a particular topic.
Therefore, you need to know what is covered in each code and recommended practice. If you are in doubt, look at the table of contents. If it does not help, look at the list of figures or tables for large volume codes, it shall give you an idea where you can find the topic. For smaller documents, peruse through table of contents or figures.
Try reading the PDF format of documents on a desktop or laptop so your eyes and mind-set gets used to them.
It seems, the brain works differently when you are looking at a hard copy of a document than when you peruse through soft copy of the same document.
Reading soft copies of reference documents help acclimatize oneself while searching for a topic. A little practice is necessary to get it right. It is particularly useful for bigger codes such as ASME Sec V & IX and API Standard 650.
Also try to memorize the topics of codes and RPs so you know where to look for. If you canāt find the relevant section after a couple of minutes, flag off the question and note the question number on a piece of paper as there is a high chance that you shall find it when looking for answers for other questions. Once found, you can go back to the flagged off question and solve it within seconds.
You are also advised to practice looking for topics in PDF format.
API Standard 653 and API RP 575, 571, 576, 577, 651 & 652 should not be a problem navigating as they are much smaller compared to ASME codes API Standard 650. There is also the content list available foreach RP.
Please note that the reference codes and RPs provided during the open book part of the exam are not word searchable, hence, you should know where to find each topic.
In the following modules, we shall be explaining and highlighting the important topics and tables supplemented with flash cards and mock exams.
This should help you get an idea where to look for.
Fortunately, the list is not exhaustive, so, you should not have problem navigating through these documents.
The Inspector must be able to calculate:
a) Metal Loss (including corrosion averaging – API 653, Section 4)
This means that the metal loss calculation will be found in Section 4. It does not mean that other sections in that document are excluded.
Note: Candidates are expected to understand the US customary units (inches, feet, PSI, etc.) and the SI units (metric system) and to use both system formulas.
In instances where the reference document is only in US customary or SI units, candidates should be prepared to respond in the units referenced.
A. Calculation questions will be oriented toward existing tanks, not new tanks.
API Authorized AST Inspectors should be able to check and perform calculations included in the following categories:
The Inspector should be able to take inspection data and determine the internal and external inspection intervals.
These calculations could be in either the āopen bookā or āclosed bookā portion of the exam. The Inspector must be able to calculate:
a) Metal Loss (including corrosion averaging ā (API 653, Section 4)
b) Corrosion Rates
c) Remaining Life
d) Remaining Corrosion Allowance
e) Inspection Interval (API 653, Section 6)
f) Remaining life (years)
g) Corrosion rate
The formulas for performing the above calculations and rules for setting the inspection intervals may be “closed book” during the exam.
The inspector should also be able to compensate for the corrosion allowance. (Add or subtract based on requirements from the exam problem.)
The inspector must be able to determine the joint efficiency, “E”, of a tank weld. Inspector should be able to determine:
a) Joint Types (API 653 Section 4, Table 4.2)
b) Type and extent of radiography performed (API 653, Table 4.2, Section 12; API 650, Section 8.1, Figure 8.1)
c) Joint efficiency by reading API 653, Table 4.2
Determining joint efficiency may be part of a minimum thickness or maximum fill height problem since joint efficiency, “E”, is used in the formulas for determining required thickness. (API 653, 4.3.3.1).
The inspector should be able to determine the maximum liquid height for a tank. To determine the height, the āt minā formula in API 653 is rearranged as follows.
This formula will be provided in the exam. The inspector is NOT expected to derive this formula by using transposition.
a) Calculate the minimum allowable thickness per Section 4 of API 653 or the maximum fill height in the localized corroded area.
b) Calculate the minimum allowable thickness per Section 4 of API 653 or the maximum fill height for an entire shell course.
The inspector should be familiar with determining the sizes and spacing of welds for shell openings to the extent of being able to use the information in the following Figures and Tables:
a) API 650, Figures 5.7a, 5.7b, 5.8, 5.9, 5.12, 5.14, 5.16, 5.17, 5.19, 5.20, 5.21
b) API 650, Tables 5.6a, 5.6b, 5.7a, 5.7b, 5.9a, 5.9b
c) API 653, Figures 9.1, 9.2, 9.4, 9.5
a) The Inspector should be familiar with the Hot Tapping requirements. (API 653, 9.15)
b) The inspector should be able to calculate the minimum spacing between an existing nozzle and a new hot tap nozzle. (API 653, 9.15.3)
The Inspector should be able to calculate the maximum allowed settlement for the following:
a) Edge Settlement (API 653 Annex B.2.3, Figure B.6)
b) Bottom Settlement Near the Tank Shell (API 653, Annex B.2.4, Figures B.7, B.8, B.10, B.11, B.12, B.13)
c) Localized Bottom Settlement Remote from the Tank Shell (API 653, Annex B.2.5, Figure B.9)
a) The inspector should be able to calculate the number of survey points for determining tank settlement. (API 653, 12.5.2, Annex B, Figure B.1, Figure B.2)
The inspector should understand the importance of tank materials having adequate toughness. The inspector should be able to determine:
a) Tank design metal temperature (API 650, 3.8, 4.2.10 & Figure 4.2)
b) Material Group Number for a plate (API 650, Tables 4.4a and 4.4b)
c) If impact testing is required (API 650, Figure 4.1a and 4.1b)
d) If impact test values are acceptable (API 650, Table 4.5a and 4.5b)
a) Calculate āSā, allowable stress (API 653, 4.3.3.1 & 4.3.4.1)
b) Determine āEā, Joint efficiency (API 653, 4.3.3.1, 4.3.4.1 & Tables 4.2 & 4.3)
c) Determine āHā, liquid height (API 653, 4.3.3.1 & 4.3.4.1)
d) Calculate minimum acceptable thickness (API 653, 4.3.3.1 & 4.3.4.1)
e) Calculate the thickness required for continued service (API 653, 4.3.3.1 & 4.3.4.1)
The inspector should be able to determine the minimum thickness of the shell of a reconstructed tank. The inspector should be able to:
a) Determine āSdā, allowable stress for design condition (API 650, Tables 5.2a and 5.2b, and API 653, 8.4.2)
b) Determine āStā, allowable stress for hydrostatic test condition (API 650, Tables 5.2a and 5.2b, and API 653,
8.4.3)
c) Calculate ātdā, design shell thickness (API 650, 5.6.3.2, for tanks of 200-ft. diameter and smaller)
d) Calculate āttā, hydrostatic test shell thickness (API 650, 5.6.3.2)
The inspector should be able to determine if a tank shell corroded area is acceptable for continued service. The inspector should be able to:
a) Select āt2ā, minimum thickness exclusive of pits for a corroded area (API 653, 4.3.2.1.a & Figure 4.1)
b) Calculate āLā, critical length for a corroded area (API 653, 4.3.2.1.b & Figure 4.1)
c) Determine āt1ā, average thickness for a corroded area (API 653, 4.3.2.1.c, 4.3.2.1.d, Figure 4.1)
d) Determine ātminā for the corroded area āHā, height and āEā, joint efficiency will be based on corroded area (API 653, 4.3.3.1)
e) Determine if tmin is acceptable (API 653, 4.3.3.1.a & 4.3.3.1.b)
The inspector should be able to evaluate a pitted area. The inspector should be able to:
a) Calculate maximum acceptable pit depth (API 653, 4.3.2.2.a)
b) Determine the maximum length of pits in any 8 in. vertical length (API 653, 4.3.2.2.b & Figure 4.2)
The inspector should be able to determine if the bottom thickness is acceptable for continued service. The inspector should be able to:
Calculate āMRTā, minimum remaining thickness at the next inspection. (API 653, 4.4.5.1)
Calculate āOā, maximum period of operation. These formulas will be provided in the exam.
a) The inspector should be able to determine the minimum dimensions for a replacement plate. (API 653, Figure 9.1)
Per API 653, 9.3 the inspector should be able to determine:
a) The minimum thickness
b) The minimum weld size
c) The allowable size of the patch plat
(NOTE: Candidates should be familiar with the basic requirements for welding qualifications for procedures and welding personnel contained in ASME Section IX. Brazing is NOT covered on the exam)
A. The inspector should have the knowledge and skills required to review a Procedure Qualification Record, Welding Procedure Specification and Welder Performance Qualification.
B.
a) Determine if procedure and qualification records are in compliance with applicable ASME Boiler and Pressure Vessel Code and any additional requirements of API 653.
The weld procedure review will include:
ā¢ Weld Procedure Specification (WPS)
ā¢ Procedure Qualification Record (PQR)
ā¢ Welder Performance Qualification (WPQ)
b) Determine if all required essential and non-essential variables have been properly addressed. (Supplemental essential variables will not be a part of the WPS/PQR).
c) Determine that the number and type of mechanical tests that are listed on PQR are the proper tests, and whether the results are acceptable.
d) Determine that the welder is qualified to make a production weld according to the WPS.
a) No more than one process will be included on a single WPS,PQR or WPQ and the WPS to be reviewed will be supported by a single PQR.
b) Filler metals will be limited to one-per-process for SMAW or GMAW
c) The PQR will be the supporting PQR for the WPS.
d) The WPQ test coupon is to be welded in accordance with a qualified WPS.
e) Base metals will be limited to P-No. 1.
The following are specifically excluded:
1) Dissimilar base metal joints
2) Supplemental powdered filler metals and consumable inserts
3) Special weld processes such as corrosion-resistant weld metal overlay, hard-facing overlay, and dissimilar metal welds with buttering
4) Charpy impact requirements and supplementary essential variables
5) Any PQR and WPS included on the exam will not include heat treatment requirements.
C. The inspector should know that the WPS must reference the applicable PQR and that the PQR must be signed and dated.
1. API Standard 650, Welded Steel Tanks for Oil Storage: The inspector should be familiar with and understand the general rules for welding in API 650, Section 9 and other rules for welding in API 650 such as those for:
a) typical joints and definitions
b) weld sizes
c) restrictions on joints
d) maximum allowable reinforcement
e) inspection requirements
API Standard 653, Tank Inspection, Repair, Alteration, and Reconstruction: The inspector should be familiar with and understand the general rules for welding in API 653, Section 11.
ASME Section V, Nondestructive Examination
NOTE: The exam will cover only the main body of each referenced Article, except as noted:
The inspector should be familiar with and understand:
1. The Scope of Section V,
2. Rules for use of Section V as a referenced Code,
3. Responsibilities of the Owner / User, and of subcontractors,
4. Calibration,
5. Definitions of āinspectionā and āexaminationā,
6. Record keeping requirements.
The inspector should be familiar with and understand:
1. The Scope of Article 2 and general requirements,
2. The rules for radiography as typically applied on butt welded AST horizontal and vertical seams such as, but not limited to:
Ā· required marking
Ā· type, selection, number, and placement of IQIs,
Ā· allowable density
Ā· control of backscatter radiation
Ā· location markers
3. Records
The inspector should be familiar with and understand:
1) The Scope of Article 6,
2) The general rules for applying and using the liquid penetrant method such as but not limited to:
a) procedures
b) contaminants
c) techniques
d) examination
e) interpretation
f) documentation
g) record keeping
(Yoke and Prod techniques only, excluding paragraphs T-765 and T-766):
The inspector should be familiar with and understand the general rules for applying and using the magnetic particle method such as but not limited to:
1. The Scope of Article 7,
2. General requirements such as but not limited to requirements for:
a) procedures
b) techniques (Yoke and Prod only)
c) calibration
d) examination
e) interpretation
3. Documentation and record keeping
Standard practice for measuring thickness by manual ultrasonic pulse-echo contact method:
The inspector should be familiar with and understand;
1. The Scope of Article 23, Section SE-797,
2. The general rules for applying and using the Ultrasonic method
3. The specific procedures for Ultrasonic thickness measurement as contained in paragraph 7.
1. API Standard 650, Welded Steel Tanks for Oil Storage: The inspector should be familiar with and understand the general rules for NDE in API 650, Section 8.
2. API Standard 653, Tank Inspection, Repair, Alteration, and Reconstruction: The inspector should be familiar
with and understand the general rules for NDE in API 653, Section 12
A. The following topics may be covered:
1. Organization and Certification Requirements.
2. Types and Definitions of Inspections.
3. Types Corrosion and Deterioration.
4. Materials and Fabrication Problems.
5. Welding.
6. Nondestructive Examination (NDE) Methods
7. Corrosion and Minimum Thickness Evaluation.
8. Estimated Remaining Life.
9. Inspection Interval Determination and Issues Affecting Intervals.
10. Inspecting Relief Devices. (API RP 576 4.3.2 & 6.6)
11. Inspection Safety Practices.
12. Inspection Records and Reports.
13. Repairs / Alterations.
14. Disassembly and Reconstruction.
15. Hydro Testing,
16. Pneumatic Testing
A. Each reference publication relative to study for the exam is listed below. A list of topics, which may be covered, is listed for each publication. Some topics may be listed under more than one publication.
For example, ASME Section IX is the basic document for welding requirements as referenced by API 650 and API 653. The referencing API documents contain additional welding requirements and exceptions or additions to those contained in ASME Section IX.
Therefore, welding requirements may be listed under all three documents and all three documents may be listed under the general heading of āWelding on Tanksā.
ATTN: Inspectors are not required to memorize the definitions of terms included in Section 3 (Definitions of Terms and Abbreviations) but are expected to be familiar with the common terms and abbreviations and be able to find definitions, if needed in the solution of a test question.
Test questions will be based on the following mechanisms only:
Section 2 Terms and Definitions
Par. 3.8 Atmospheric Corrosion
3.11 Brittle Fracture
3.14 Caustic Corrosion
3.15 Caustic Stress Corrosion Cracking (Caustic Embrittlement)
3.17 Chloride Stress Corrosion Cracking
3.22 Corrosion Under insulation (CUI)
3.43 Mechanical Fatigue (Including Vibration-induced Fatigue)
3.45 Microbiologically Influenced Corrosion (MIC)
3.57 Soil Corrosion
3.58 Sour Water Corrosion (Acidic)
3.62 Sulfuric Acid Corrosion
NOTE: API RP 575 is a Recommended Practice and contains many general statements that are not strict requirements.
Some questions on the exam related to API RP 575 may contain phrases such as āit is best toā or āan inspector would normallyā when information or statements from API RP 575 are covered.
In these cases, it is important to be familiar with the content of API RP 575 and to be able to pick the best answer of those given. All of API RP 575 is applicable to the exam unless specifically excluded.
A. The inspector should have a practical understanding and be familiar with the information contained in API RP 575 as related to:
1. types of tanks covered
2. procedures to perform internal and external inspection
3. the types of external and internal inspections
4. procedures to determine suitability for continued service
5. evaluation change-of-service effects on suitability for continued service
6. evaluation and general condition of:
a) distortions, flaws, windgirders, stiffeners, welds, and nozzles
b) tank bottoms
c) tank foundations
d) causes of corrosion, leaks, cracks, and mechanical deterioration
e) auxiliary equipment.
f) anchor bolts, pipe connections, ground connections
g) insulation.
h) shells and roofs
1. Safety Relief Valve (API RP 576, 4.2.4)
2. Inspection, Testing, Maintenance, and Setting of Weight-loaded Pressure and/or Vacuum Vents on Tanks (API RP 576, 6.6)
1. Definitions
2. Welding inspection
3. Welding processes
4. Welding procedure
5. Welding materials
6. Welder qualifications
7. Non-destructive examination
8. Metallurgy
9. Refinery and Petrochemical Plant Welding Issues
10. Terminology and symbols
11. Actions to address improperly made production welds
12. Welding procedure review
13. Guide to common filler metal selection
14. Example report of RT results
(NOTE: all of API 653 is applicable to the exam unless specifically excluded.)
A. Tank Inspection, NDE, and Testing
1. The inspector should have a practical understanding and be familiar with the information contained in API 653 related to general inspection practices such as:
a) types of tanks covered
b) applicable inspection tasks for internal and external inspection (e.g., API Standard 653, Annex C, Checklists for Tank Inspection).
c) safe working practices
d) thickness and dimensional measurements and tolerances
e) requirements of external and internal inspections
f) frequencies and intervals for external and internal inspection
g) alternatives to the required internal inspection intervals
h) NDE procedures and NDE personnel qualification requirements
i) types of roofs and seals and types of deterioration
j) reasons for inspection and causes of deterioration of storage tanks
k) procedures to check or test storage tanks for leaks
l) tools and equipment for tank inspection
m) failure assessment and deterioration of auxiliary equipment
n) suitability for continued service.
o) change-of-service effects on suitability for continued service
p) evaluation of tank bottom conditions
q) evaluate tank foundation conditions
r) risk of failure due to brittle fracture
s) evaluate the causes of corrosion, leaks, cracks, and mechanical deterioration.
t) evaluate the condition of anchor bolts, pipe connections, ground connections, and insulation
2. The inspector should have an understanding and be able to perform calculations related to: (See also previous section on āCALCULATIONS FOR EVALUATING THICKNESS MEASUREMENTS AND TANK INTEGRITYā)
a) actual and minimum required thickness for shell plates
b) maximum allowable fill height
c) required thickness for hydrotesting and for elevated temperatures
d) evaluation of corroded areas and pits on shell plates
e) t min, corrosion rate, inspection interval and remaining corrosion allowance
f) distortions, flaws, welds, and nozzles.
g) minimum thickness for tank bottoms and annular plate rings and shell rings
h) evaluate the effects of tank bottom settlement and acceptable limits
i) evaluate the condition of tank shells and roofs.
j) weld size at roof-to-shell and bottom-to-shell junctions per design requirements
3. The inspector should understand the requirements for performing repairs and alterations such as:
a) definitions of repairs and alterations
b) repairs to foundations, shell plates, welds, tank bottoms, nozzles & penetrations, roofs, seals
c) knowledge of the repair/alteration material and toughness requirements
d) use of unidentified materials for repairs/alterations
e) hot tap requirements and procedures
f) inspection and NDE requirements for repairs and alterations
g) hydrostatic and leak testing requirements
h) lap-welded patch plates (API 653, 9.3 and Figure 9.3)
i) new bottoms supported by grillage API 650, Annex I, excluding calculations).
4. The inspector should have an understanding of the requirements for recording the inspection data and records related to inspection, repairs, and alterations such as:
a) nameplate requirements
b) record-keeping requirements
c) reports for inspection, repair and alterations
NOTE: Only Sections 1, 2, 3, 4, 5, 6, 8, and 11 will be covered on the exam.
A. The inspector should have a practical understanding and be familiar with the information contained in API RP 651 related to:
1. Corrosion of Aboveground Steel Storage Tanks
2. Determination of Need for Cathodic Protection
3. Methods of Cathodic Protection for Corrosion Control
4. Operation and Maintenance of Cathodic Protection Systems
B. Information contained in API RP 651 which the inspector will not be examined on:
1. design of cathodic protection systems
2. sources, detection, and control of interference currents
A. The inspector should have a practical understanding and be familiar with the information contained in API RP 652 related to:
1. types of tank bottom linings and advantage and disadvantages of each
2. considerations for recommending tank bottom linings
3. causes of tank bottom lining failures
4. types of tank bottom lining materials
5. surface preparation requirements for the installation of tank bottom linings
6. issues affecting the application of a tank bottom lining