Section 1 Introduction & Workbook
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Transcript of Section 1 Introduction & Workbook
This manual was prepared by BAY Technical Associates, Inc
Statement
This course manual has been prepared by BAY Technical Associates, Inc., strictly for the use of attendees to Hellier's API-653 Examination Preparation Course. This manual is to be used as an aid to assist those persons wishing to take the API-653 Aboveground Storage Tank Inspector Certification Examination. This manual is not all-inclusive and may not be used in place of any recognized Code or Standard.
The information contained in this manual was obtained from the authors research and experience and through numerous published resources including:
American Petroleum Institute Codes, Standards, and Recommended Practices:
API-653, Tank Inspection, Repair, Alteration, and Reconstruction
API-650, Welded Steel Tanks for Oil Storage
API-575, Inspection of Atmospheric and Low Pressure Storage Tanks
API-651, Cathodic Protection of Aboveground Petroleum Storage Tanks
API-652, Lining of Aboveground Petroleum Storage Tank Bottoms
API-2015, Cleaning Petroleum Storage Tanks
API-2207, Preparing Tank Bottoms for Hoe Work
American Society of Mechanical Engineers (ASME) Boiler & Pressure Vessel Codes:
ASME Section V, Nondestructive Examination
ASME Section IX, Welding and Brazing Qualifications
The Procedure Handbook of Arc Welding, Twelfth Edition: The Lincoln Electric Co.
Metals and How to Weld Them, Second Edition: The James F. Lincoln Arc Welding Foundation.
This manual may not be reproduced by any means without the express written consent of BAY Technical Associates, Inc.
Preface
The API-653 Aboveground Storage Tank Inspector Certification Examination consists of two parts; an Open Book part and a Closed Book part. The open book portion of the examination contains approximately thirty-five to forty (35 to 40) questions. This part of the examination requires the use of detailed information that the inspector must be able to research in the permitted documents, and is not expected to have committed to memory. Not all open book questions are mathematical in nature. The closed book portion of the examination represents the remaining questions. Some of the closed book questions require the applicant to perform basic math; remember to have your calculator available. The closed book portion tests the inspector on knowledge and tasks requiring everyday working knowledge of API Standard 653 and the applicable reference documents.
This examination preparation course is designed to prepare the participant to successfully sit for the API-653 exam. Through your concentrated effort, and the material provided in this course, you should have sufficient information to pass the examination.
The majority of the classroom study will focus on the Open Book portion of the exam. The goal, since this is open book, is to obtain a perfect score in this section. Study for the practical questions (Closed Book) will be included in the daily classroom activity and assigned homework.
The material contained in this manual is to be thoroughly studied and practiced prior to attending the course. The math examples and practice problems are based on the types of questions given on the API-653 exam. Through the use of these examples, you will be exposed to many of the formulas used during the course.
Remember, this is a very intense course. There will be eight hours of classroom study each day. The instructor will be available by phone, fax, or e-mail each evening between 7:00pm and 9:00pm to answer questions or to assist any participant having difficulty with the homework assignments or any topic discussed during class. There will be from two to three hours of homework assignments each day. Daily quizzes are given and one practice API-653 examination is provided. The pace is fast and focused.
The participant is responsible for making all arrangements for taking the examination including confirming your eligibility and applying to the American Petroleum Institute.
Introduction:
Objective for this section:
At the end of this section, you should be able to:
1. List the required reference manuals you must bring to the course
2. List the reference material permitted during the exam
3. Know where you can obtain ASME and API Code books
4. List what material will be provided during the course
5. Explain the structure of the API-653 Exam
How to use this Pre-Course Study Guide:
1.Review the basic math skills section and complete the practice math test.
2.Complete the reading assignments,
3.Research and answers the questions in the "Practical Questions" section of this study guide (chapters 3 through 11).
4.Compare your answers with the answer guide at the end of each section.
Required Reference MaterialYou must bring the following API Standards, API Recommended Practices (RP), ASME Code books, and material with you to the course:
1.API Standard 650, Welded Steel Tanks for Oil Storage, 10th Edition
2. API Standard 653, Tank Inspection, Repair, Alteration, and Reconstruction, 2nd Edition, December 1995; including Addendum 1 - 3
3. API Standard 2015, Safe Entry and Cleaning of Petroleum Storage Tanks, 5th Edition (May 1994)
4. API Publication 2207, Preparing Tank Bottoms for Hot Work, 5th Edition (September 1998)
5 API RP - 575, Inspection of Atmospheric & Low Pressure Storage Tanks, 1st Edition, (November, 1995)
6. API RP - 651, Cathodic Protection of Aboveground Petroleum Storage Tanks, 2nd Edition (December 1997)
7.API RP - 652, Lining of Aboveground Storage Tank Bottoms, 2nd Edition (December 1997)
8.ASME Section V, Nondestructive Examination, 1998 Edition
9.ASME Section IX, Welding and Brazing Qualifications, 1998 Edition
10.This Study Manual
11.Non-Programmable Calculator
To order ASME Code books, you may call the ASME at 1(800) THE-ASME (843-2763) or you can write them at:
ASME Order Department
22 Law Drive
Box 2300
Fairfield, NJ 07007-2300
To order API Documents, you may call them at: 1(202) 682-8375 or you can write them at:
American Petroleum Institute
Order desk
1220 L Street
Washington, DC 20005
Hellier and BAY Technical Associates, Inc. will not provide Code books.
Hellier and BAY Technical Associates, Inc. will provide:
1. Pre-course Study Manual
2. Student Reference Manual (Provided on Day-one)
3. Certificate of Completion
Hellier and BAY Technical Associates, Inc. will have available for reference:
1. Welding reference books
2. Overhead transparencies
3. Various applicable reference documents
The structure of the API-653 Examination:
The API-653 Examination is given on Saturday March 25,2000. The exam consists of a closed book portion, usually given first and an open book portion, usually given after everyone has finished the closed book portion. You will have not more than five hours to complete the entire examination. The questions consist of multiple choice and true/false type questions.
You are permitted and required to use the following Reference books during the open book portion of the exam:
1.API Standard 650, Welded Steel Tanks for Oil Storage, 10th Edition
2. API Standard 653, Tank Inspection, Repair, Alteration, and Reconstruction, 2nd Edition, December 1995; including Addendum 1 - 3
3. API Standard 2015, Safe Entry and Cleaning of Petroleum Storage Tanks, 5th Edition (May 1994)
4. API Publication 2207, Preparing Tank Bottoms for Hot Work, 5th Edition (September 1998)
5 API RP - 575, Inspection of Atmospheric & Low Pressure Storage Tanks, 1st Edition, (November, 1995)
6. API RP - 651, Cathodic Protection of Aboveground Petroleum Storage Tanks, 2nd Edition (December 1997)
7.API RP - 652, Lining of Aboveground Storage Tank Bottoms, 2nd Edition (December 1997)
8.ASME Section V, Nondestructive Examination, 1998 Edition
9.ASME Section IX, Welding and Brazing Qualifications, 1998 Edition
No reference material of any kind will be permitted during the closed book portion; some examining proctors may permit language translation dictionaries. There will be some common knowledge mathematical questions on the practical portion of the exam - remember to have your calculator available for this part of the exam.
During this course, we will attempt to duplicate actual examination conditions including using a separate answer sheet during the practice examination.
NOTES
Reading Assignments:
At the end of this section, you should:
1.Have completed the reading assignments
2.Be familiar with the layout and structure of each API Standard, API Recommended Practice, and ASME Code Book used in the course and on the exam. (These Standards, RPs, and Code books will be referred to as "Reference books" in this section)
3.Compile a list of questions concerning paragraphs/subjects you do not understand.
The classroom portion of this American Petroleum Institute examination preparation course is focused on the "open book" portion of the exam. A thorough understanding each reference book is essential in order to answer the closed book questions on the exam. All Reference books will be reviewed and discussed during the course. Many hours of the homework assignments will be reading selected portions of each Reference book.
The course begins up-to-speed on day one and continues until the practice exam. It is essential that you complete the "pre-course" reading assignments. You are not expected understand all that you read, but the familiarity gained will assist you in keeping up and not becoming overwhelmed on the first day of class. If during the course of reading this material, you have questions, do not dwell too long on the subject. Write your question down and be sure to ask for clarification during the course.
Do not try to memorize Reference book paragraphs at this time, selected portions will be pointed out for highlighting and memorization during the course. Studying and researching the example questions and answers provided in the "Pre-Course Workbook and Study Guide" should be sufficient for exam purposes. The first thing one realizes, when they begin working with these Reference books, is that they are dynamic and change constantly. An inspector should never rely on memorized passages, but should instead always research the answer to a question; that is why understanding the structure of the Reference books is imperative.
Reading Assignments:
It is highly recommended that you obtain a set of tabs or binder index pages. The API permits tabs, indexes, highlighting, underlining, and some written notes; they do not permit any type of inserted pages in the Reference books.
API Standard 650, Welded Steel Tanks for Oil Storage:
TitleParagraph(s)Pages(s)
ForewordAlliii
Asbestos InformationAlliv
Required Ordering InformationAllxiii
Section 1 - ScopeAll1-1 through 1-4
Section 2 - MaterialsAll2-1 through 2-8
Section 4 - FabricationAll4-1
Section 7 - WeldingAll7-1 through 7-2
Section 8 - MarkingAll8-1 through 8-2
API Standard 653, Tank Inspection, Repair, Alteration, and Reconstruction:
Entire document must be read. You should be thoroughly familiar with this standard.
API Standard 2015, Safe Entry and Cleaning of Petroleum Storage Tanks
Read this entire document - remember this is a safety code to help ensure your ability to survive your daily work. The API takes a dim view of your answers to questions if they could result in injury to yourself or others.
API Publication 2207, Preparing Tank Bottoms for Hot Work
Entire document must be read. You should be thoroughly familiar with this publication
API Recommended Practice 651, Cathodic Protection of Aboveground Petroleum Storage Tanks
Sections 1 through 6 - Pages 1 through paragraph 6.3.5 on page 11.
Recommended Practice 652, Lining of Aboveground Petroleum Storage Tank Bottoms
Entire document must be read. You should be thoroughly familiar with this RP.
Recommended Practice 575, Inspection Atmospheric and Low Pressure Storage Tanks
Entire document must be read. You should be thoroughly familiar with this RP
ASME Section V Nondestructive Examination:
Title
Paragraph(s)
Subsection A - Article 1All
Subsection A - Article 2T-210 through T-292
Subsection A - Article 4T-410 through T-494
Subsection A - Article 5T-510 through T-594
Subsection A - Article 6T-600 through T-690
Subsection A - Article 7T-710 through T-791
ASME Section IX, Welding and Brazing Qualifications:
Title
Paragraph(s)
ForewordAll
IntroductionAll
Part QW - Article IQW-100 through QW-196.2.2
Part QW - Article IIQW-200 through QW-251.4
Part QW - Article IIIQW-300 through QW-361.2(h)
Part QW - Article IVQW-400 through QW-401.5
Part QW - Article IVGraphics QW-460 through 461.9
Pre-Course Workbook Practice Mathematics
Objective:At the end of this section, you should:
1. Be familiar with the basic types of mathematics used on the exam.
2.Have taken and self graded the pre and post math tests
3.Have reviewed the basic mathematical functions and obtained assistance where needed
4.Worked the practice problemsA Pre-Test is provided on pages 15 & 16 with the answers on page 20 & 21
Practice problems are provided on pages 17 through 19 with the answers on pages 22 & 23
A Post-Test is provided on page 24 with answers on pages 25 & 26
MATHCalculation questions found on the API-653 examination are oriented toward existing tanks and not new tanks. API authorized above ground storage tank inspectors are expected to be able to check and perform calculations necessary to ensure compliance with appropriate Codes and standards. For this reason, the inspector must have a thorough understanding of the formulas and procedures used to calculate the following:
Corrosion Rates and Inspection Intervals
Remaining Life determination
Joint Efficiencies
Maximum Height (Hydrostatic Testing)
Determining appropriate weld sizes for shell opening
Minimum spacing between existing and new hot tap nozzles
Settlement evaluation including the number of survey points
Minimum Thickness for Existing Tank and Reconstructed Tank Shells
Corroded areas of tank shells including evaluation of pitting
Bottom plate thickness determination and evaluation
Reinforcement of opening
The American Petroleum Institute does not permit the use of programmable calculators while taking the exam; therefore, programmable calculators will not be permitted during the course.
A recommended answer sheet layout format for use during the course is provided in this section. Using the layout will help keep your procedures straight and make it easier for you to check your work.
The remainder of this section deals with the typical mathematical skill level required. It is divided into modules: Pre-Test, Basic Math Functions, and Post-Test. Typically, if a formula requires transposing, the appropriate formula is given in the examination question however, you should have a basic understanding of Algebra. Completion and understanding of this portion of the pre-course manual will increase your chances of passing the exam as well as enhancing your ability to keep up with the pace during the course. Should you have difficulty with any portion of this math section, you should obtain assistance. In any case, you should complete all the problems and practice them until you are comfortable with them.
Recommended Math Page Layout
NamePage Number
Answer (a)
Problem NumberPage ____of_____Answer (b)
Answer (c)
Answer (d)
Drawing if Applicable
Given Information:Final Formula
Formula with Variables Plugged In
Show all Work
Find:
Reference:
Formula to use:
Formula Transposition
Answer:
Recommended Math Page LayoutName:Page Number
Answer (a)
Problem NumberPage ____of_____Answer (b)
Answer (c)
Answer (d)
Drawing if Applicable
Given Information:Final Formula
Formula with Variables Plugged In
(Note:) At this point make sure you have: a value for each variable, included the correct sign, and included the correct information within any parentheses or brackets)
Show all Work
Find: (what does the question ask)
Reference: (Code book and paragraph)
Formula to use:
Formula Transposition
Answer:
Mathematics Fundamentals:
As we all know, mathematics has a language of its own, made up of signs, symbols, and characters. During this course of study many common mathematical signs, symbols, and characters, which you must be familiar with, will be used. Some of these are listed below.
(Addition
(Subtraction
(
( )Multiplication
Division
(Pi Expressed as 3.14
(Less than
(Greater than
(Therefore
(Less than or equal to
(Greater than or equal to
(Equal
X2Number squared
Square root
In addition to the symbols, we will use the common Arabic numerals 1,2,3,4, (etc) and the letters of the alphabet to develop our mathematical problems and solutions. How we use this language is determined by the structure of the question.
In our use of the language of math, all equations must be complete and retain their equality throughout in order to be useful. One of the first things that must be clear is the order in which operations must be performed. An operation is a function caused by the sign in the equation. For instance, the + sign tells us to add two or more characters together. In the following statement 12+87 doesnt tell us anything; just two numbers separated by an addition sign. If we add the = sign, now the statement asks a question: 12+87=X, when we replace the X with the correct answer we have completed the equation ( 12+87=99 is a true statement and meets all the requirements of an equation for our purposes.
Order of Operations and Grouping:
OperationGrouping
1. Addition1. Parentheses ( )
2. Subtraction2. Brackets [ ]
3. Multiplication3. Braces { }
4. Division
Clarification:
At this point, it is assumed that the participant is already familiar with the basics of addition, subtraction, multiplication, and division.
Finding areas of shapes will follow customary rules. The area of a circle can be found using A = ( R2 or A = (.7854)(d2).
Algebra
The first rule in algebraic statements is the equality of the equation must remain throughout the steps leading to the final solution. In other words, the left side of the equal sign must always equal the right side of the equal sign. In order to ensure this, always remember: whatever you do to one side of the equal sign, you must also do to the other side of the equal sign.
Lets look at the following equation:
If we know all the variables except the minimum required design thickness, we can transpose the formula to solve for the thickness.
Pre-Test:
1.Find the minimum acceptable shell plate thickness of the first course of an AST.
tmin= Minimum acceptable thickness?
D= Nominal diameter of tank, in feet120
H= Height of tank in feet48
G= Specific gravity of contents1
S= Maximum allowable stress21000
E= Joint efficiency of tank.85
2.Find the corrosion rate of an AST given the following information.
Original thickness = .875
Measured thickness = .625
Years since last thickness measurement = 11
3.Using the corrosion rate determined in problem number 2, what would the remaining life expectancy of this tank be if the minimum required thickness is 0.436?
4.Shell settlement evaluation measurements are to be taken on a 146 feet diameter AST. Given the following formula, how many elevation measurements would be required?
5.Using the information in number four, does this number meet the requirements of API-653, which does not permit the measurement points to exceed 32 feet?
Pre-Test continued:
6.Find the throat of a right angle fillet weld with a weld leg length of .4375 inches.
7.Using the following information, what is the maximum vertical length (also known as critical length), in inches, over which hoop stresses are assumed to average out around local discontinuities? Diameter of the tank is 136 feet, the least thickness in an area of corrosion, exclusive of pits, is determined to be .563
8.A 6 inch nozzle is to be placed in the tank shell of an AST. The shell course where the nozzle will be installed is .875 thick. What is the required area of reinforcement?
9.The maximum ultrasonic thickness measurement interval shall be five years when the corrosion rate is not known. What is the interval based on a known corrosion rate? The tank information is as follows: Initial thickness of the tank was 1.0625, the actual thickness is .815, the calculated required thickness is .473, the tank has been in service for 16 years with no measurements taken since it was installed.
RCA = .342
N = .015
10.What is the circumference of an AST that is 96 feet in diameter?
Practice problems #1:Problem #1
Find S when tmin, D, H, G, and E are known where: D=78, H=29, G = 1, E=.85, and tmin =.602
Problem #2
Find E when D, H, G, S, G, and tmin are known where: D =128, H=60, S = 22,300 G = .87, and tmin = 1.125
Problem #3
Find D when H, E, S, G, and tmin are known where: H=45, E=.90, S=22500, G= .7 and tmin =.9375
Problem #4
Find St when E, Ht, D, G, and tmin are know where: E = .80, Ht = 54, D= 70, G = 1 and tmin =.4325
Problem #5
Find C when D and H are know where D = 60, H = 54
Lets go a step farther:
What do we do when our Unknown is inside a radical (square root symbol)?
We know all the values except for the d
Practice Problems #2
Problem # 1
Find d when a=1.0755
Problem # 2
Find D when t=.875, L=32.5
Problem # 3
Find tinitial when LlongtermCR=.015, Tyears = 19 and tlast = 1.134
Practice Problems # 3Problem # 1 ( Exponents:
(a) 43 = ? (b) (23)(24) = ? (c) Calculator display (1.0137-3 would be written as ?
Problem # 2 ( Square Root:
(a) (b) (c) Find t
Problem # 3 ( Fractions:
(a) (b) (c) (d)
(e) (f) (g) (h)
(i) (j) (k) (l)
Problem # 4 ( Ratios and Proportions:
(a) (b) (c)
Problem # 5 ( Area:
A 24-inch nozzle is to be installed in a 1.0625 thick shell course. What is the required area of reinforcement?
Pre-Test: ANSWERS1.Find the minimum acceptable shell plate thickness of the first course of an AST.
Tmin= Minimum acceptable thickness?
D= Nominal diameter of tank, in feet120
H= Height of tank in feet48
G= Specific gravity of contents1
S= Maximum allowable stress21000
E= Joint efficiency of tank.85
2.Find the corrosion rate of an AST given the following information.
Original thickness = .875
Measured thickness = .625
Years since last thickness measurement = 11
3.Using the corrosion rate determined in problem number 2, what would the remaining life expectancy of this tank be if the minimum required thickness is 0.436?
4.Shell settlement evaluation measurements are to be taken on a 146 feet diameter AST. Given the following formula, how many elevation measurements would be required?
5.Using the information in number four, does this number meet the requirements of API-653, which does not permit the measurement points to exceed 32 feet?
Distance = 30.5ft. yes meet requirements
Reference: API-653 Paragraph 10.5.1.2 definition of N
Pre-Test continued: ANSWERS6.Find the throat of a right angle fillet weld with a weld leg length of .4375 inches.
Throat = (.707)(.4375) Throat = .309
7.Using the following information, what is the maximum vertical length (also known as critical length), in inches, over which hoop stresses are assumed to average out around local discontinuities? Diameter of the tank is 136 feet, the least thickness in an area of corrosion, exclusive of pits, is determined to be .563
8.A 6 inch nozzle is to be placed in the tank shell of an AST. The shell course where the nozzle will be installed is .875 thick. What is the required area of reinforcement?
A = (6.75)(.875) = 5.906 square inches API-650 3.7.2.1 & 3.7.2.2
9.The maximum ultrasonic thickness measurement interval shall be five years when the corrosion rate is not known. What is the interval based on a known corrosion rate? The tank information is as follows: Initial thickness of the tank was 1.0625, the actual thickness is .815, the calculated required thickness is .473, the tank has been in service for 16 years with no measurements taken since it was installed.
RCA = .342
N = .015
API-653 4.3.3.2 b.
10.What is the circumference of an AST that is 96 feet in diameter?
Circumference = (D Circumference = (3.14)(96) = 301.44 feet.
Practice problems #1:Problem #1
Find S when tmin, D, H, G, and E are known where: D=78, H=29, G = 1, E=.85, and tmin =.602
S = 11493.4
Problem #2
Find E when D, H, G, S, G, and tmin are known where: D =128, H=60, S = 22,300 G = .87, and tmin = 1.125
E = .692
Problem #3
Find D when H, E, S, G, and tmin are known where: H=45, E=.90, S=22500, G= .7 and tmin =.9375
Problem #4
Find St when E, Ht, D, G, and tmin are know where: E = .80, Ht = 54, D= 70, G = 1 and tmin =.4325
Problem #5
Find C when D and H are know where D = 60, H = 54
Practice Problems #2
Problem # 1
Find d when a=1.0755
Problem # 2
Find D when t=.875, L=32.5 (
Problem # 3
Find tinitial when LlongtermCR=.015, Tyears = 19 and tlast = 1.134
Practice Problems # 3Problem # 1 ( Exponents:
(a) 43 = 64 (b) (23)(24) = 27 or 128 (c) Calculator display (1.0137-3 is written as .0010137
Problem # 2 ( Square Root:
(a) = 3.4641 (b) =1.3993
(c) Find t2 or
Problem # 3 ( Fractions:
(a)
EMBED Equation.3 (b)
EMBED Equation.3 (c)
EMBED Equation.3 (d)
EMBED Equation.3
(e)
EMBED Equation.3 (f)
EMBED Equation.3 (g)
EMBED Equation.3 (h)
EMBED Equation.3 (i)
EMBED Equation.3 (j)
EMBED Equation.3 (k)
EMBED Equation.3 (l)
EMBED Equation.3 Problem # 4 ( Ratios and Proportions:
(a) 6 (b) 9 (c) 10
Problem # 5 ( Area:
A 24-inch nozzle is to be installed in a 1.0625 thick shell course. What is the required area of reinforcement? API-650 Para. 3.7.2.1 & 3.7.2.2 (24)(1.0625) = 25.5 sq in
Post Test:
1.What is the required hydrostatic test height (Ht) of an AST given the following data?
Maximum allowable hydrostatic stress (St)= 21350
Diameter of the tank = 110 feet
Hydrostatic test shell thickness (tmin) is .625
Shell joint efficiency = 70%
Use API-653 2.3.3.1 formula for tanks to be hydrostatically tested.
2.What is the area of a tank bottom that is 121 feet in diameter?
3.A reinforcing plate is installed around a nozzle installed in the first course of an AST. What is the throat dimension of the leg fillet weld around the periphery of the reinforcing plate.
4.What is the minimum acceptable thickness of the bottom course of an existing AST that is 135 feet in diameter, maximum fill height is 56.5 feet? The product stored in the tank has a specific gravity of .87 and all shell butt-welds were 100% radiographically examined. The yield strength of the material is 28,000 and the tensile strength is 60,000. Use API-653 paragraph 2.3.3.1.
5.What is the required area of reinforcement for a 14 NPS nozzle installed in a shell course that is 1.0625 thick. Use API 650 Paragraph 3.7.2.1
6.A bulge is noted in a tank bottom, what is the maximum height of the bulge permitted if the radius of the inscribed circle is 10.8 feet? Use API-653 Appendix B 3.3
7.If the throat of a fillet weld is .309, what is the leg length of the weld?
8.An AST is 175 feet in diameter. How many tank settlement survey points are required? Use API-653 paragraph 10.5.1.2.
9.Do the number of settlement measurement locations and maximum spacing comply with API 653? Use API 653 Paragraph 10.5.1.2
10.What is the design liquid level of an AST that is 140 feet in diameter, thickness of the bottom or first course is .765, stress of the material is 21300. The specific gravity of the product to be stored is 1 and no corrosion allowance is needed nor provided.
(
Post Test Answers
1.What is the required hydrostatic test height (Ht) of an AST given the following data?
Maximum allowable hydrostatic stress (St)= 21350
Diameter of the tank = 110 feet
Hydrostatic test shell thickness (tmin) is .625
Shell joint efficiency = 70%
Use API-653 2.3.3.1 formula for tanks to be hydrostatically tested.
(
2.What is the area of a tank bottom that is 121 feet in diameter?
A = (3.14)(60.5)2 A = (3.14)(3660.25) A = 11493 sqft
3.A reinforcing plate is installed around a nozzle installed in the first course of an AST. What is the throat dimension of the leg fillet weld around the periphery of the reinforcing plate.
Throat = .707Wleg Throat = (.707)(.5) = .3535
4.What is the minimum acceptable thickness of the bottom course of an existing AST that is 135 feet in diameter, maximum fill height is 56.5 feet? The product stored in the tank has a specific gravity of .87 and all shell butt-welds were 100% radiographically examined. The yield strength of the material is 28,000 and the tensile strength is 60,000. Use API-653 paragraph 2.3.3.1.
( (
S = (.8)(28000) = 24640 S = (.429)(60000) = 25740
5.What is the required area of reinforcement for a 14 NPS nozzle installed in a shell course that is 1.0625 thick.
Area = (14)(1.0625) = 14.875 square inches
Post Test Answers
6.A bulge is noted in a tank bottom, what is the maximum height of the bulge permitted if the radius of the inscribed circle is 10.8 feet?
B = .37R ( B = (.37)(10.8) = 3.996 inches or 4 inches
7.If the throat of a fillet weld is .309, what is the leg length of the weld?
( (
8.An AST is 175 feet in diameter. How many tank settlement survey points are required? Use API-653 paragraph 10.5.1.2.
(
9.Do the number of settlement measurement locations and maximum spacing comply with API 653?
Yes ( (175)(3.14) = 549.3 ( 549.3 ( 18 = 30.5 feet spacing
10.What is the design liquid level of an AST that is 140 feet in diameter, thickness of the bottom or first course is .765, stress of the material is 21300. The specific gravity of the product to be stored is 1 and no corrosion allowance is needed nor provided.
( ( ( H = 44.76 + 1 ( H = 45.76 feet
Step 1 -To eliminate the radical, we must do the opposite of its function. The opposite function of extracting a square root is to square the variable. We square both sides of the equation.
Step 2 - .7854 is divided by d. The opposite of division is multiplication; therefore we multiply both sides by the d
Step 3 - a2 is multiplied by d. We perform the opposite function and divide both sides by a2
API-653 Exam Prep CourseBAY Technical Associates, Inc.(610) 594-9036
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