Understandings API ICP653 Reading 9 - Q&A Practices Work Sheet 04 API653 储罐认证, Q&A作业学习 31st January 2016
Charlie Chong/ Fion Zhang
Tank Farms
Charlie Chong/ Fion Zhang
Charlie Chong/ Fion Zhang
Adobe Acrobat Reader Hotkeys Ctrl + G = find again Ctrl + L = full screen Ctrl + M = zoom to Ctrl + N = go to page (insert number in box) Ctrl + Q = quit program Ctrl + + = zoom in Ctrl + - = zoom out Ctrl + 0 = fit in window Ctrl + 1 = actual size Ctrl + 2 = fit width Ctrl + 3 = fit visible Ctrl + 4 = reflow Ctrl + Shift + A = deselect all Ctrl + Shift + F = search query Ctrl + Shift + G = search results Ctrl + Shift + J = cascade windows Ctrl + Shift + K = tile windows horizontally Ctrl + Shift + L = tile windows vertically Charlie Chong/ Fion Zhang
http://allhotkeys.com/adobe_acrobat_reader_hotkeys.html
Ctrl + Shift + S = save a copy Ctrl + Shift + P = page setup Ctrl + Shift + W = search word assistant Ctrl + Shift + X = search select indexes Ctrl + Shift + Page Up = first page Ctrl + Shift + Page Down = last page Ctrl + Shift + + = rotate clockwise Ctrl + Shift + - = rotate counterclockwise Ctrl + Alt + W = close all Alt + Left Arrow = go to previous view Alt + Right Arrow = go to next view Alt + Shift + Left Arrow = go to previous document Alt + Shift + Right Arrow = go to next document F4 = thumbnails F5 = bookmarks F8 = hide toolbars F9 = hide menu bar
Charlie Chong/ Fion Zhang
http://en.wikipedia.org/wiki/Table_of_keyboard_shortcuts http://help.adobe.com/en_US/acrobat/using/WS58a04a822e3e50102bd615109794195ff-7aed.w.html
Charlie Chong/ Fion Zhang
Fion Zhang at Shanghai 31st January 2016
Charlie Chong/ Fion Zhang
API 653 Exam Administration -- Publications Effectivity Sheet FOR: November 2015, March 2016 and July 2016 Listed below are the effective editions of the publications required for this exam for the date(s) shown above. API Recommended Practice 571, Damage Mechanisms Affecting Fixed Equipment in the Refining Industry, Second Edition, April 2011
Charlie Chong/ Fion Zhang
API 653 Exam Administration -- Publications Effectivity Sheet FOR: November 2015, March 2016 and July 2016 Listed below are the effective editions of the publications required for this exam for the date(s) shown above. API Recommended Practice 571, Damage Mechanisms Affecting Fixed Equipment in the Refining Industry, Second Edition, April 2011
Charlie Chong/ Fion Zhang
ATTENTION: Only the following sections / mechanisms from RP 571 are included on the exam: Section 3, Definitions Par. 4.2.7 Brittle Fracture 4.2.16 Mechanical Fatigue 4.3.2 Atmospheric Corrosion 4.3.3 Corrosion Under insulation (CUI) 4.3.8 Microbiologically Induced Corrosion (MIC) 4.3.9 Soil Corrosion 4.3.10 Caustic Corrosion 4.5.1 Chloride Stress Corrosion Cracking (Cl-SCC) 4.5.3 Caustic Stress Corrosion Cracking (Caustic Embrittlement) 5.1.1.10 Sour Water Corrosion (Acidic) 5.1.1.11 Sulfuric Acid Corrosion
Charlie Chong/ Fion Zhang
API Recommended Practice 575, Inspection of Atmospheric and LowPressure Storage Tanks, Third Edition, April 2014 API Recommended Practice 577 – Welding Inspection and Metallurgy, Second Edition, December 2013 API Standard 650, Welded Tanks for Oil Storage, Twelfth Edition, March 2013 with Addendum 1 (September 2014), Errata 1 (July 2013), and Errata 2 (December 2014). API Recommended Practice 651, Cathodic Protection of Aboveground Petroleum Storage Tanks, Fourth Edition, September 2014. API Recommended Practice 652, Lining of Aboveground Petroleum Storage Tank Bottoms, Fourth Edition, September 2014 API Standard 653, Tank Inspection, Repair, Alteration, and Reconstruction, Fifth Edition, November 2014.
Charlie Chong/ Fion Zhang
American Society of Mechanical Engineers (ASME), Boiler and Pressure Vessel Code, 2013 Edition i. ASME Section V, Nondestructive Examination, Articles 1, 2, 6, 7 and 23 (section SE-797 only) ii. Section IX, Welding and Brazing Qualifications (Welding Only) ď Ž
See end of this study note for API Official BOK
Charlie Chong/ Fion Zhang
Charlie Chong/ Fion Zhang
http://independent.academia.edu/CharlieChong1 http://www.yumpu.com/zh/browse/user/charliechong http://issuu.com/charlieccchong
Charlie Chong/ Fion Zhang
Charlie Chong/ Fion Zhang
http://greekhouseoffonts.com/
The Magical Book of Tank Inspection ICP
Charlie Chong/ Fion Zhang
Charlie Chong/ Fion Zhang
闭门练功
Charlie Chong/ Fion Zhang
闭门练功
Charlie Chong/ Fion Zhang
API 650 PRACTICE QUESTIONS Section 1 – Scope Q1. API 650 covers the design, materials, fabrication, erection, and testing of aboveground steel storage tanks. What is the maximum internal pressure for tanks not covered by appendix F of this standard? a) Maximum pressure shall not exceed 15 psig b) Maximum pressure shall not exceed 15 psia c) Maximum pressure shall not exceed the weight of the roof plates d) Maximum pressure shall not exceed the weight of the floor plates Reference: API-650, Paragraph 1.1.1 ANS:C
Charlie Chong/ Fion Zhang
Q2. API-650 applies only to tanks whose entire bottom is uniformly supported and tanks in ___ that have a maximum operating temperature of _____°F. a) Any petrochemical service and temperature not exceeding 120°F b) Non-refrigerated service and temperature not exceeding 200°F c) Non-refrigerated service and temperature not exceeding 120°F d) Any petrochemical service and temperature not exceeding 200°F Reference: API-650, Paragraph 1.1.1 ANS:B
Charlie Chong/ Fion Zhang
Q3. An aboveground storage tank is to be subjected to a small internal service pressure. To which standard or Code may the tank be designed? a) API-650 providing the requirements of Appendix F are met b) API-653 providing the requirements of Appendix F are met c) ASME-Section VIII, Div. 1 providing the requirements of Appendix F are met d) ASME-Section VIII, Div. 2 providing the requirements of Appendix F are met Reference: API-650, Paragraph 1.1.1 ANS:A
Charlie Chong/ Fion Zhang
Q4. According to Table 1-1, what is the status of Appendix O? a) This Appendix is a Recommendation b) This Appendix is a Requirement c) This Appendix is Mandatory d) This Appendix is Purchaser’s option Reference: API-650, Paragraph 1.1.19 and Table 1-1 ANS:D Q5. What is the purpose of the ( ) next to a paragraph number? a) The paragraph requires a decision or action by the API b) The paragraph requires a decision or action by the Inspector c) The paragraph requires a decision or action by the purchaser d) The paragraph requires a decision or action by the fabricator Reference: API-650, Paragraph 1.1.2 and Note ANS:C
Charlie Chong/ Fion Zhang
Answers to API-Standard 650 Section 1, Scope
Charlie Chong/ Fion Zhang
Section 2 – Materials Q1. API-650 lists materials to be used in the construction of tanks covered by the standard. Is it permissible to use materials other than those listed in the standard? a) No only materials listed in API-650 may be used in tank fabrication b) Yes as long as the manufacturer accepts full liability for tank failure c) Yes providing it is certified as meeting all requirements of a material listed in API-650 and is approved by the API-653 Inspector d) Yes providing it is certified as meeting all the requirements of a material listed in API-650 and is approved by the purchaser Reference: API-650, Paragraph 2.1.1 ANS: D
Charlie Chong/ Fion Zhang
Q2. If a new or unused plate cannot be completely identified, may it still be used in the construction of tanks within the scope of API-650? a) Yes only if the material passes the tests prescribed in Appendix S b) Yes only if the material passes the tests prescribed in Appendix N c) Yes only if the material passes the tests prescribed in ASME Section V d) Yes only if the material passes the tests prescribed in ASME Section VIII, Div. 2 Reference: API-650, Paragraph 2.1.2 ANS:B Q3. What is the maximum permitted underrun for shell, roof, and bottom plates? a) 0.10 inch from the computed design thickness or minimum permitted thickness b) 0.01 inch from the computed design thickness or minimum permitted thickness c) 0.001 inch from the computed design thickness or minimum permitted thickness d) 0.02 inch from the computed design thickness or minimum permitted thickness Reference: API-650, Paragraph 2.2.1.2.3 ANS:B Charlie Chong/ Fion Zhang
Q4. Shell plates are limited to what maximum thickness? a) Shell plates are limited to a maximum thickness of 1.250 inches b) Shell plates are limited to a maximum thickness of 1.875 inches c) Shell plates are limited to a maximum thickness of 1.750 inches d) Shell plates are limited to a maximum thickness of 1.075 inches Reference: API-650, Paragraph 2.2.1.4 ANS: C Q5. Which of the following is not a requirement for shell plates that are thicker than 1.5 inches? a) Plates thicker than 1.5 inches shall be free of mill scale and painted b) Plates thicker than 1.5 inches shall be made to fine-grain practice c) Plates thicker than 1.5 inches shall be impact tested d) Plates thicker than 1.5 inches shall be normalized or quench tempered Reference: API-650, Paragraph 2.2.1.4 ANS: A
Charlie Chong/ Fion Zhang
Q6. What is the maximum shell plate thickness permitted for a tank fabricated of ASTM A36 material? a) This plate material is limited to 1.750 inches b) This plate material is limited to 1.075 inches c) This plate material is limited to 1.050 inches d) This plate material is limited to 1.500 inches Reference: API-650, Paragraph 2.2.2 a ANS: D Q7. What is the maximum shell plate thickness permitted for a tank fabricated of ASTM A285, Grade C material? a) This plate material is limited to 1.000 inches b) This plate material is limited to 1.250 inches c) This plate material is limited to 1.500 inches d) This plate material is limited to 1.750 inches Reference: API-650, Paragraph 2.2.2 d ANS: A
Charlie Chong/ Fion Zhang
API650: 4.2.2 ASTM Specifications Plates that conform to the following ASTM specifications are acceptable as long as the plates are within the stated limitations. a) ASTM A36M/A36 for plates to a maximum thickness of 40 mm (1.5 in.). None of the specifications for the appurtenant materials listed in Table 1 of ASTM A36M/A36 are considered acceptable for tanks constructed under this standard unless it is expressly stated in this standard that the specifications are acceptable. d) ASTM A285M/A285, Grade C, for plates to a maximum thickness of 25 mm (1 in.).
Charlie Chong/ Fion Zhang
Q8. All welding to repair surface defects shall be done with ______. a) Cellulose coated electrode b) High nickel content electrode c) Low-hydrogen electrode d) Gas tungsten process Reference: API-650, Paragraph 2.2.6.2 ANS:C Q9. When conducting impact tests, how many specimens are required from a single test coupon? a) Impact tests shall be performed on a single specimen taken from a single test coupon b) Impact tests shall be performed on two specimens taken from a single test coupon c) Impact tests shall be performed on three specimens taken from a single test coupon d) Impact tests shall be performed on four specimens taken from a single test coupon Reference: API-650, Paragraph 2.2.8.3 ANS: C
Charlie Chong/ Fion Zhang
Q10. In situations where it is not possible to obtain full size specimens, what is the required width along the notch for subsize specimens? a) 60% of the material thickness b) 80% of the material thickness c) 90% of the material thickness d) 75% of the material thickness Reference: API-650, Paragraph 2.2.8.5 ANS: B Q11. Unless data is available to justify a different temperature, what must the design metal temperature be for an aboveground storage tank to be installed in Birmingham, Alabama? a) The design temperature shall be assumed to be 25째F b) The design temperature shall be assumed to be 15째F c) The design temperature shall be assumed to be 20째F (?) d) The design temperature shall be assumed to be 10째F Reference: API-650, Paragraph 2.2.9.3 and Figure 2-2 ANS:?
Charlie Chong/ Fion Zhang
API650: 4.2.9.5 For a plate whose thickness is insufficient to permit preparation of fullsize specimens [10 mm × 10 mm (0.394 in. × 0.394 in.], tests shall be made on the largest subsize specimens that can be prepared from the plate. Subsize specimens shall have a width along the notch of at least 80 % of the material thickness. Figure 4.2—Isothermal Lines of Lowest One-Day Mean Temperatures (°F)
Charlie Chong/ Fion Zhang
Annex L (normative) API Standard 650 Storage Tank Data Sheet Design Metal Temperature*: Enter either lowest 1-day mean temperature plus 8 째C (15 째F) or a lower temperature as specified by the Purchaser if operating conditions and/or local atmospheric conditions control fracture toughness issues.
째F
Charlie Chong/ Fion Zhang
Q12. Unless data is available to justify a different temperature, what must the design metal temperature be for an aboveground storage tank to be installed in Indianapolis, Indiana? a) The design temperature shall be assumed to be 5°F b) The design temperature shall be assumed to be -5°F c) The design temperature shall be assumed to be 0°F d) The design temperature shall be assumed to be 10°F Reference: API-650, Paragraph 2.2.9.3 and Figure 2-2 ANS: -10°F+15°F=5°F Q13. What is the required average longitudinal impact value of three specimens taken from a 1.375 inch thick A 516M-60(415) normalized Group IIIA test coupon? a) 30 foot-pounds b) 20 foot-pounds c) 15 foot-pounds d) 13 foot-pounds Reference: API-650, Paragraph 2.2.10.2 and Figures 2-3 and 2-4 ANS: C
Charlie Chong/ Fion Zhang
Annex L (normative) API Standard 650 Storage Tank Data Sheet Design Metal Temperature*: Enter either lowest 1-day mean temperature plus 8 째C (15 째F) or a lower temperature as specified by the Purchaser if operating conditions and/or local atmospheric conditions control fracture toughness issues.
Charlie Chong/ Fion Zhang
Q14. What is the required average longitudinal impact value of three specimens taken from a 1.5 inch thick A 516M-70(485) as rolled Group V test coupon? a) 35 foot-pounds b) 25 foot-pounds c) 20 foot-pounds d) 30 foot-pounds Reference: API-650, Paragraph 2.2.10.2 and Figures 2-3 and 2-4 ANS: D
Charlie Chong/ Fion Zhang
Table 4.5b—Minimum Impact Test Requirements for Plates (USC) (See Note)
Charlie Chong/ Fion Zhang
Q15. Longitudinal impact tests are performed on three specimens, taken from a 1.5 inch thick A 516M-70(485) as rolled test coupon with the following results: Specimen #1 – 42 foot-pounds, Specimen #2 – 18 foot-pounds, Specimen # 3 – 31 foot-pounds. Is the impact test acceptable? a) Yes the average impact value exceeds 30 foot-pounds b) Yes only one specimen is less than 2/3 the specified minimum value c) No the average impact value of Specimen # 1 exceeds 2/3 the required average impact value and one specimen is less than 2/3 the specified minimum value d) No Specimen #2 is less than 2/3 the specified minimum Reference: API-650, Paragraph 2.2.8.3 and Figures 2-3 and 2-4 ANS: D
Charlie Chong/ Fion Zhang
API650: 4.2.9.3 An impact test shall be performed on three specimens taken from a single test coupon or test location. The average value of the specimens (with no more than one specimen value being less than the specified minimum value) shall comply with the specified minimum value. If more than one value is less than the specified minimum value, or if one value is less than two-thirds the specified minimum value, three additional specimens shall be tested, and each of these must have a value greater than or equal to the specified minimum value.
Charlie Chong/ Fion Zhang
Answers to API-Standard 650 Section 2, Materials
Charlie Chong/ Fion Zhang
Section 3 – Design Q1. According to API-650, tack welds _______ a) May be installed by welders who need practice b) Can be considered as adding to the strength of a welded joint c) Are not considered as having any strength value in the finished structure d) Have strength value in the finished structure provided they are performed by a qualified welder to a qualified welding procedure Reference: API-650, Paragraph 3.1.3.2 ANS: C Q2. What is the minimum size fillet weld permitted when joining a 1” thick plate to a ¾” thick plate? a) 3/16” b) 1/4” c) 3/8” d) 1/2” Reference: API-650, Paragraph 3.1.3.3 ANS: B, 1/3 of ¾ = ¼”
Charlie Chong/ Fion Zhang
API650: 5.1.3.3 The minimum size of fillet welds shall be as follows: On plates 5 mm (3/16 in.) thick, the weld shall be a full- fillet weld, and on plates more than 5 mm (3/16 in.) thick, the weld thickness shall not be less than one-third the thickness of the thinner plate at the joint and shall be at least 5 mm (3/16 in.).
Charlie Chong/ Fion Zhang
Q3. For lap-welded joints that are tack welded, what is the minimum amount of lap permitted? a) The lap need not exceed 2� b) The lap need not exceed 1� c) The joint shall be lapped at least 5 times the minimum required thickness of the thinner plate d) The joint shall be lapped at least 5 times the nominal thickness of the thinner plate Reference: API-650, Paragraph 3.1.3.5 ANS: D Q4. The welded joint pictured here is defined as what type of joint? a) Double-V butt joint b) Square-groove butt joint c) Double-U butt joint d) Double-square butt joint Reference: API-650, Paragraph 3.1.5.1 ANS: A
Charlie Chong/ Fion Zhang
Q5. Vertical shell joints may be partial penetration groove welds welded from both sides. a) True b) False Reference: API-650, Paragraph 3.1.5.2 a ANS:B Q6. API 650 requires the vertical joints in adjacent shell courses to be offset. What is the minimum required offset between the first course of an AST, which is 1.25� thick and the second course which is 1� thick? a) The minimum offset shall be 5 times the second shell course height b) The minimum offset shall be 5 times the thickness of the second course c) The minimum offset shall be 5 times the first shell course height d) The minimum offset shall be 5 times the thickness of the first shell course Reference: API-650, Paragraph 3.1.5.2 b ANS: D
Charlie Chong/ Fion Zhang
API650: 5.1.5.1 General b) Vertical joints in adjacent shell courses shall not be aligned, but shall be offset from each other a minimum distance of 5t, where t is the plate thickness of the thicker course at the point of offset.
Charlie Chong/ Fion Zhang
Q7. Three-plate laps in tank bottoms shall be at least ____ from each other, from the tank shell, from butt-welded annular-plate joints, and from joints between annular plates and the bottom. a) 1.2 inches b) 12 inches c) 1.2 feet d) 12 feet Reference: API-650, Paragraph 3.1.5.4 ANS:B Q8. What is the maximum size of fillet weld permitted in the attachment between the lowest course shell plate and the bottom plate? a) 3/8 inch b) 5/16 inch c) 1/2 inch d) 1/4 inch Reference: API-650, Paragraph 3.1.5.7 ANS: C
Charlie Chong/ Fion Zhang
Q9. What is the minimum size fillet weld required on each side of the shell plate attaching shell plate to the annular plate? The shell plate is 1.25� thick. a) 3/8 inch b) 3/16 inch c) 1/4 inch d) 5/16 inch Reference: API-650, Paragraph 3.1.5.7ANS: D Q10. A 110 ft diameter tank shall have a top angle not less than ____ inches. a) 2 X 2 X 3/8 b) 2 X 3 X 3/8 c) 3 X 3 X 3/8 d) 3 X 2 X 3/8 Reference: API-650, Paragraph 3.1.5.9 ANS: C
Charlie Chong/ Fion Zhang
5.1.5.7 Shell-to-Bottom Fillet Welds a) For bottom and annular plates with a nominal thickness 13 mm (1/2 in.), and less, the attachment between the bottom edge of the lowest course shell plate and the bottom plate shall be a continuous fillet weld laid on each side of the shell plate. The size of each weld shall not be more than 13 mm (1/2 in.) and shall not be less than the nominal thickness of the thinner of the two plates joined (that is, the shell plate or the bottom plate immediately under the shell) or less than the following values:
Charlie Chong/ Fion Zhang
b) For annular plates with a nominal thickness greater than 13 mm (1/2 in.), the attachment welds shall be sized so that either the legs of the fillet welds or the groove depth plus the leg of the fillet for a combined weld is of a size equal to the annular-plate thickness (see Figure 5.3c), but shall not exceed the shell plate thickness.
Charlie Chong/ Fion Zhang
API650: 5.1.5.9 Roof and Top-Angle Joints e) Except as specified for open-top tanks in 5.9, for tanks with frangible joints per 5.10.2.6, for self-supporting roofs in 5.10.5, and 5.10.6, and for tanks with the flanged roof-to-shell detail described in Item f below, tank shells shall be supplied with top angles of not less than the following sizes:
Charlie Chong/ Fion Zhang
Q11. The ______ shall state the design metal temperature, the design specific gravity, the corrosion allowance, and the design wind velocity. a) The purchaser b) The fabricator c) The Inspector d) Erector Reference: API-650, Paragraph 3.2.1 ANS: A Q12. According to API-650, tanks meeting the minimum requirements of the standard may be subjected to a partial vacuum of _____. a) One inch of mercury b) One inch of water pressure c) One pound per square inch absolute d) One centimeter of water pressure Reference: API-650, Paragraph 3.2.4ANS: B
Charlie Chong/ Fion Zhang
API650: 5.2 Design Considerations 5.2.1 Loads Loads are defined as follows. a) Dead Load (DL): The weight of the tank or tank component, including any corrosion allowance unless otherwise noted. b) b) Design External Pressure (Pe): Shall not be less than 0.25 kPa (1 in. of water) except that the Design External Pressure (Pe) shall be considered as 0 kPa (0 in. of water) for tanks with circulation vents meeting Annex H requirements. Refer to Annex V for design external pressure greater than 0.25 kPa (1 in. of water). Requirements for design external pressure exceeding this value and design requirements to resist flotation and external fluid pressure shall be a matter of agreement between the Purchaser and the Manufacturer (see Annex V). Tanks that meet the requirements of this standard may be subjected to a partial vacuum of 0.25 kPa (1 in. of water), without the need to provide any additional supporting calculations. c) Design Internal Pressure (Pi): Shall not exceed 18 kPa (2.5 lbf/in.2).
Charlie Chong/ Fion Zhang
Q13. An AST is 116 ft in diameter and constructed of A 516M-70(485) Group V as rolled material. How many hardness tests are required on one circumferential weld? a) One b) Two c) Three d) Four Reference: API-650, Paragraph 3.3.4 ANS: D Q14. The purchaser orders an aboveground storage tank and insists on a corrosion allowance in the bottom plates of .125 inches. What is the minimum thickness permitted for bottom plates in this tank? a) Minimum thickness of bottom plate is 1/4 inch b) Minimum thickness of bottom plate is 1/2 inch c) Minimum thickness of bottom plate is 3/8 inch d) Minimum thickness of bottom plate is 5/16 inch Reference: API-650, Paragraph 3.4.1 ANS: C
Charlie Chong/ Fion Zhang
5.3.4 Weld Hardness a) Weld metal and Heat Affected Zone (HAZ) hardnesses shall comply with the H2S Supplemental Specification listed on the Data Sheet, Line 5, when specified by the Purchaser. b) When specified by the Purchaser, the hardness of the weld metal for shell materials in Group IV, IVA, V, or VI shall be evaluated by one or both of the following methods. 1. The welding-procedure qualification tests for all welding shall include hardness tests of the weld metal and heat- affected zone of the test plate. The methods of testing and the acceptance standards shall be agreed upon by the Purchaser and the Manufacturer. 2. All welds deposited by machine or an automatic process shall be hardness tested on the product-side surface. Unless otherwise specified, one test shall be conducted for each vertical weld, and one test shall be conducted for each 30 m (100 ft) of circumferential weld. The methods of testing and the acceptance standards shall be agreed upon by the Purchaser and the Manufacturer.
Charlie Chong/ Fion Zhang
Q15. What is the minimum projection, of trimmed bottom plates, beyond the outside edge of the weld attaching bottom to the shell? a) Minimum projection is 0.01 inch b) Minimum projection is 0.10 inch c) Minimum projection is 1.00 inch d) Minimum projection is 10.0 inch Reference: API-650, Paragraph 3.4.2 ANS: C Q16. Annular bottom plates shall have a radial width that provides at least ____ between the inside of the shell and any lap-welded joint in the remainder of the bottom. a) 12 inches b) 24 inches c) 1.2 inches d) 2.4 inches Reference: API-650, Paragraph 3.5.2 ANS: A
Charlie Chong/ Fion Zhang
Q17. How far must annular bottom plates project outside the shell? a) Annular bottom plates shall project at least 1 inch when trimmed b) Annular bottom plates shall project at least 1/2 inch beyond the edge of the weld c) Annular bottom plates shall project at least 2 inches outside the shell d) Annular bottom plates shall project at least 5t (t = thickness of the shell course) outside the shell Reference: API-650, Paragraph 3.5.2 ANS: A
ď Ž Trimmed bottom plates shall project at least 1 inches outside the shell ď Ž Annular bottom plates shall project at least 2 inches outside the shell
Charlie Chong/ Fion Zhang
Q18. The thickness of the first shell course of an aboveground storage tank is 1 5/8th inches. The hydrostatic test stress in the first shell course is 33,000 psi. What is the minimum permissible thickness of the annular bottom plates? a) Minimum permitted thickness is 5/8th inch b) Minimum permitted thickness is 9/16th inch c) Minimum permitted thickness is 3/4 inch (?) d) Minimum permitted thickness is 11/16th inch Reference: API-650, Paragraph 3.5.3 and Table 3-1 ANS: A Q19. According to API-650, what is the minimum allowable nominal shell thickness of an AST that is 86 feet in diameter? a) Minimum nominal shell thickness is 3/16th inch b) Minimum nominal shell thickness is 1/4 inch c) Minimum nominal shell thickness is 9/32nd inch d) Minimum nominal shell thickness is 5/16th inch Reference: API-650, Paragraph 3.6.1.1ANS: B
Charlie Chong/ Fion Zhang
Table 5.1b—Annular Bottom-Plate Thicknesses (tb) (USC)
Charlie Chong/ Fion Zhang
Q20. Unless otherwise agreed to by the purchaser, what is the minimum nominal width of shell plates? a) Minimum width of shell plates is 84 inches b) Minimum width of shell plates is 96 inches c) Minimum width of shell plates is 72 inches d) Minimum width of shell plates is 120 inches Reference: API-650, Paragraph 3.6.1.2 ANS: C Q21. Aboveground storage tank manufacturers are required to furnish a drawing to the purchaser listing all but which of the following for each course? a) The material specification b) The allowable stress c) The nominal thickness used d) The nominal thickness of coatings Reference: API-650, Paragraph 3.6.1.7ANS: D
Charlie Chong/ Fion Zhang
Q22. In calculating the net plate thickness for an AST fabricated of A 516M Grade 450(60) material, what would be the product design stress value used in the calculation? a) 24,000 b) 21,300 c) 32,000 d) 23,300 Reference: API-650, Paragraph 3.6.2.1 and Table 3-2 ANS: B Q23. The fabricator of an AST obtains the approval of the purchaser to use the alternative shell design permitted in Appendix A in the design of a 60 foot diameter tank using 3/8th inch A 516M Grade 450(60) plate. What allowable stress would be used in the design calculations? a) 21,300 b) 24,000 c) 21,000 d) 32,000 Reference: API-650, Paragraph 3.6.2.3 ANS: C
Charlie Chong/ Fion Zhang
API650: A.3 Design A.3.1 The maximum tensile stress before the joint efficiency factor is applied shall be 145 MPa (21,000 lbf/in.2). A.3.2 Stresses shall be computed on the assumption that the tank is filled with water (specific gravity = 1.0) or with the liquid to be stored if it is heavier than water. A.3.3 The tension in each ring shall be computed 300 mm (12 in.) above the centerline of the lower horizontal joint of the course in question. When these stresses are computed, the tank diameter shall be taken as the nominal diameter of the bottom course.
Charlie Chong/ Fion Zhang
Q24. What is the maximum diameter of tank that permits the 1-foot method of calculation for required thickness? a) Tanks 50 feet in diameter and less b) Tanks 120 feet in diameter and less c) Tanks 180 feet in diameter and less d) Tanks 200 feet in diameter and less Reference: API-650, Paragraph 3.6.3.1: ANS: D Q25. Openings in tank shells, larger than that required to accommodate a ____ flanged or threaded nozzle shall be reinforced. a) 2 inch b) 2.5 inch c) 3 inch d) 3.5 inch Reference: API-650, Paragraph 3.7.2.1 ANS: A
Charlie Chong/ Fion Zhang
Q26. When installing openings in a shell plate, the edge of the fillet weld around the periphery of the reinforcing pad shall be spaced at least the greater of _______ from the centerline of any butt-welded shell joints. a) Eight inches or ten times the weld size b) Eight times the weld size or ten inches c) Eight times the weld size or six inches d) Eight inches or six times the weld size Reference: API-650, Paragraph 3.7.3.1 a ANS: B Q27. When installing openings adjacent to each other, how much space must there be between the welds around the periphery of the reinforcing plate? a) Eight times the larger weld or ten inches from each other b) Eight inches or six times the larger weld from each other c) Eight times the larger weld or six inches from each other d) Eight times the larger weld or eight inches from each other Reference: API-650, Paragraph 3.7.3.1 b ANS: C
Charlie Chong/ Fion Zhang
5.7.3 Spacing of Welds around Connections 5.7.3.1 For non-stress-relieved welds on shell plates over 13 mm (1/2 in.) thick, the minimum spacing between penetration connections and adjacent shell-plate joints shall be governed by the following. a) The toe of the fillet weld around a non-reinforced penetration or around the periphery of a reinforcing plate, and the outer edge of a butt-weld around the periphery of a thickened insert plate or insert plate, shall be spaced at least the greater of eight times the weld size or 250 mm (10 in.) from the centerline of any butt-welded shell joints, as illustrated in Figure 5.6, dimensions A or B. b) The toe of the fillet weld around a non-reinforced penetration or around the periphery of a reinforcing plate, and the outer edge of a butt-weld around the periphery of a thickened insert plate or insert plate, shall be spaced at least the greater of eight times the larger weld size or 150 mm (6 in.) from each other, as illustrated in Figure 5-6, dimension E.
Charlie Chong/ Fion Zhang
Figure 5.6—Minimum Weld Requirements for Openings in Shells According to 5.7.3
Charlie Chong/ Fion Zhang
Figure 5.6—Minimum Weld Requirements for Openings in Shells According to 5.7.3
Charlie Chong/ Fion Zhang
Figure 5.6—Minimum Weld Requirements for Openings in Shells According to 5.7.3
Charlie Chong/ Fion Zhang
Q28. A minimum distance of ____ shall be maintained between the toe of a weld around a non-reinforced penetration and the toe of the shell-tobottom weld. a) Ten inches b) Eight inches c) Six inches d) Three inches Reference: API-650, Paragraph 3.7.3.3 ANS: D Q29. Subject to the acceptance of the purchaser, the manufacture may locate a circular shell opening in a horizontal butt-welded shell joint provided ______. a) Minimum spacing dimensions are met and a liquid penetrant examination of the welded joint is conducted b) Minimum spacing dimensions are met and a radiographic examination of the welded joint is conducted c) Minimum spacing dimensions are met and an ultrasonic examination of the welded joint is conducted d) Minimum spacing dimensions are met and a magnetic particle examination of the welded joint is conducted Reference: API-650, Paragraph 3.7.3.4 ANS: B
Charlie Chong/ Fion Zhang
Figure 5.6—Minimum Weld Requirements for Openings in Shells According to 5.7.3
Charlie Chong/ Fion Zhang
API650: 5.7.3.4 Nozzles and manholes should not be placed in shell weld seams and reinforcing pads for nozzles and manholes should not overlap plate seams (i.e. Figure 5.9, Details a, c, and e should be avoided). If there is no other feasible option and the Purchaser accepts the design, circular shell openings and reinforcing plates (if used) may be located in a horizontal or vertical butt-welded shell joint provided that the minimum spacing dimensions are met and a radiographic examination of the welded shell joint is conducted. The welded shell joint shall be fully radiographed for a length equal to three times the diameter of the opening, but the weld seam being removed need not be radiographed. Radiographic examination shall be in accordance with 8.1.3 through 8.1.8.
Charlie Chong/ Fion Zhang
Q30. All flush-type clean-out fittings and flush-type shell connections shall be thermally stress relieved after assembly and prior to installation in the tank. What are the temperature range and time requirements for this stress relief activity? a) 1100°F to 1200°F for 1 hour per inch of reinforcing plate thickness b) 1100°F to 1200°F for 1/2 hour per inch of shell thickness c) 1100°F to 1200°F for 1 hour per inch of shell thickness d) 1100°F to 1200°F for 1 & 1/2 hour per inch of shell thickness Reference: API-650, Paragraph 3.7.4.1 ANS: C Q31. Subject to the acceptance of the purchaser, the fabricator may stress relieve at a temperature of 1000°F when it is impractical to stress relieve at a minimum temperature of 1100°F providing _____. a) The shell plate is first pre-heated to 300°F b) The holding time is increased to 2 hours per inch of thickness c) The holding time is increased to 4 hours per inch of thickness d) The holding time is increased to 10 hours per inch of thickness Reference: API-650, Paragraph 3.7.4.5 ANS: C
Charlie Chong/ Fion Zhang
Q32. What is the minimum required thickness for a manhole cover plate to be used with a 24 inch manhole? The maximum design liquid level of the tank is 45 feet. a) Minimum thickness of cover plate is 9/16th inch b) Minimum thickness of cover plate is 5/8th inch c) Minimum thickness of cover plate is 1/2 inch d) Minimum thickness of cover plate is 11/16th inch Reference: API-650, Paragraph 3.7.5.1 and Table 3-3 ANS: A Q33. What is the bolt circle diameter for a cover plate used with a 30 inch diameter manhole? a) 32 ¾ inch b) 36 ¼ inch c) 38 ¾ inch d) 42 ¼ inch Reference: API-650, Paragraph 3.7.5.2 and Table 3-5 ANS: B
Charlie Chong/ Fion Zhang
Q34. The purchaser has ordered a 36 inch manhole to be installed in the first course of an AST. The thickness of the shell plate and the reinforcing plate is 1.375 inches. What is the required hole diameter that must be cut in the tank to accommodate this manhole? a) 36 & 1/4 inch b) 36 & 1/2 inch c) 36 & 3/4 inch d) 36 & 5/8 inch Reference: API-650, Paragraph 3.7.5.3 and Table 3-7 ANS: C Q35. API 650 requires telltale holes in reinforcing plates. What is the required dimension of this hole and what should be done with it after the initial repad pressure test? a) The hole shall be 3/8 inch diameter and shall be left open to the atmosphere b) The hole shall be 1/4 inch diameter and shall be left open to the atmosphere c) The hole shall be 3/8 inch diameter and shall be closed after testing d) The hole shall be 1/4 inch diameter and shall be closed after testing Reference: API-650, Paragraph 3.7.6.1 ANS:
Charlie Chong/ Fion Zhang
Table 5.7b—Dimensions for Shell Nozzles: Pipe, Plate, and Welding Schedules (USC)
Charlie Chong/ Fion Zhang
Table 5.7b—Dimensions for Shell Nozzles: Pipe, Plate, and Welding Schedules (USC)
Charlie Chong/ Fion Zhang
Q36. What is the maximum size un-reinforced opening permitted in flat cover plates without increasing the thickness of the cover plate? a) 4 inch pipe size providing the edge of the opening is not more than ¼ the height or diameter of the opening closer to the center of the cover plate b) 3 inch pipe size providing the edge of the opening is not more than ¼ the height or diameter of the opening closer to the center of the cover plate c) 2 inch pipe size providing the edge of the opening is not more than ¼ the height or diameter of the opening closer to the center of the cover plate d) 1 & ½ inch pipe size providing the edge of the opening is not more than ¼ the height or diameter of the opening closer to the center of the cover plate Reference: API-650, Paragraph 3.8.3.1 ANS: C Q37. What is the maximum size opening that may be placed in a cover plate? a) 12 inches pipe size b) 8 inches pipe size c) 6 inches pipe size d) 3 inches pipe size Reference: API-650, Paragraph 3.8.3.2 ANS: A
Charlie Chong/ Fion Zhang
Q38. An aboveground storage tank has a design liquid height of 40 feet. The purchaser intends to install product mixing equipment in the cover plate of a 30 inch manhole. What is the required minimum thickness of the cover plate? a) The minimum thickness shall be at least .625 inches b) The minimum thickness shall be at least .75 inches c) The minimum thickness shall be at least .9375 inches d) The minimum thickness shall be at least .875 inches Reference: API-650, Paragraph 3.8.3.2 ANS: D
Charlie Chong/ Fion Zhang
API650: 5.8.3 Cover Plates A cover plate with a nozzle attachment for product-mixing equipment shall have a thickness at least 1.4 times greater than the thickness required by Table 5.3a and Table 5.3b. The added thickness (or pad plate) for replacement of the opening cutout in the cover plate shall be based on Table 5.3a and Table 5.3b. The 40 % increase in thickness within a radius of one diameter of the opening may be included as part of the area of replacement required. The mixer- nozzle attachment to the cover plate shall be a fullpenetration weld. The manhole bolting-flange thickness shall not be less than 1.4 times the thickness required by Table 5.3a and Table 5.3b. The manhole nozzle neck shall be designed to support the mixer forces with a minimum thickness not less than the requirements
Charlie Chong/ Fion Zhang
Table 5.3b—Thickness of Shell Manhole Cover Plate and Bolting Flange (USC)
11/16 x 1.4 x 40/43.9 = 0.877”
Charlie Chong/ Fion Zhang
Q39. A 24 inch manhole is to be installed in a roof plate and it is anticipated that work may be carried on through the manhole while the tank is in use. What is the diameter of the opening to be cut in the roof plate and what is the outside diameter of the reinforcing plate? a) The diameter of the opening is 24.625” and the OD of the reinforcing plate is 42” b) The diameter of the opening is 24.625” and the OD of the reinforcing plate is 46” c) The diameter of the opening is 24.750” and the OD of the reinforcing plate is 42” d) The diameter of the opening is 24.750” and the OD of the reinforcing plate is 46” Reference: API-650, Paragraph 3.8.4 ANS: B
Charlie Chong/ Fion Zhang
Figure 5.16—Roof Manholes (see Table 5.13a and Table 5.13b)
Charlie Chong/ Fion Zhang
Q40. What is the minimum thickness permitted for rectangular roof opening cover plates? a) Minimum thickness shall not be less than .875 inches b) Minimum thickness shall not be less than .750 inches c) Minimum thickness shall not be less than .625 inches d) Minimum thickness shall not be less than .500 inches Reference: API-650, Paragraph 3.8.6.2 ANS: D Q41. Stiffening ring splice welds shall be located at least _____ from any vertical shell weld. a) 24 inches b) 18 inches c) 12 inches d) 6 inches Reference: API-650, Paragraph 3.9.3.4 ANS: D
Charlie Chong/ Fion Zhang
API650: 5.9.3.4 Welds joining stiffening rings to the tank shell may cross vertical tank seam welds. Any splice weld in the ring shall be located a minimum of 150 mm (6 in.) from any vertical shell weld. Stiffening rings may also cross vertical tank seam welds with the use of coping (rat hole) of the stiffening ring at the vertical tank seam. Where the coping method is used, the required section modulus of the stiffening ring and weld spacing must be maintained.
Charlie Chong/ Fion Zhang
Q42. When stiffening rings are to be used as walkways, what is the required width of the stiffening ring? a) The width shall be not less than 36 inches clear of the projecting curb angle on the top of the tank shell b) The width shall be not less than 3 feet 6 inches clear of the projecting curb angle on the top of the tank shell c) The width shall be not less than 24 inches clear of the projecting curb angle on the top of the tank shell d) The width shall be not less than 2 feet 4 inches clear of the projecting curb angle on the top of the tank shell Reference: API-650, Paragraph 3.9.4 ANS: C Q43. How far below the top of the curb angle should a stiffening ring, that is to be used as a walkway, be located? a) 3 feet 6 inches b) 36 inches c) 6 feet 3 inches d) 63 inches Reference: API-650, Paragraph 3.9.4ANS: A
Charlie Chong/ Fion Zhang
API650: 5.9.4 Stiffening Rings as Walkways A stiffening ring or any portion of it that is specified as a walkway shall have a width not less than 710 mm (28 in.) clear of projections including the angle on the top of the tank shell. The clearance around local projections shall not be less than 610 mm (24 in.). Unless the tank is covered with a fixed roof, the stiffening ring (used as a walkway) shall be located 1100 mm (42 in.) below the top of the curb angle and shall be provided with a standard railing on the unprotected side and at the ends of the section used as a walkway.
Charlie Chong/ Fion Zhang
Q44. All roofs and supporting structures shall be designed to support dead loads plus a uniform live load of not less than _____ of projected area a) 25 pounds per square inch b) 25 pounds per square foot c) 25 pounds per square yard d) 25 pounds per square meter Reference: API-650, Paragraph 3.10.2.1 ANS: B Q45. What is the minimum nominal thickness permitted for roof plates? a) 3/16 inch or 5.76 pounds per square foot b) 3/16 inch or 6.75 pounds per square foot c) 3/16 inch or 7.65 pounds per square foot d) 3/16 inch or 12-gauge sheet Reference: API-650, Paragraph 3.10.2.2 ANS: C
Charlie Chong/ Fion Zhang
Q46. A roof where the continuous fillet weld between the roof plates and the top angle does not exceed 3/16", the slope at the top angle attachment does not exceed 2" in 12", and the shell-to-roof compression ring details are limited to Figure F-2 (a)-(d) may be considered what type of roof? a) A 1 in 6 roof b) A dangerous roof design and should be avoided c) A roof with inherent compensation d) A frangible roof Reference API-650, Paragraph 3.10.2.5.1 ANS: D Q47. Rafters shall be spaced so that in the outer ring, their centers are not more than _____ apart measured along the circumference of the tank. a) 3π feet or 9.42 feet b) 2π feet or 6.28 feet c) 4π feet or 12.56 feet d) 2.5π feet or 7.85 feet Reference: API-650, Paragraph 3.10.4.4ANS: B
Charlie Chong/ Fion Zhang
Answers to API-Standard 650 Section 3, Design
Charlie Chong/ Fion Zhang
Section 4 – Fabrication Q1. What method(s) is/are permitted for straightening material? a) Pressing or other non-injurious method prior to layout or shaping b) Heating and hammering after layout or shaping c) Jacking into shape after final assembly d) Jacking into shape and holding with tack welds Reference: API-650, Paragraph 4.1.1.2 ANS: A Q2. When plates are to be butt-welded, shearing is limited to what maximum thickness? a) 5/8th inch b) 3/8th inch (9.5mm) c) 3/16th inch d) Shearing is not permitted Reference: API-650, Paragraph 4.1.2ANS: B
Charlie Chong/ Fion Zhang
Q3. When plates are to be used in lap-welded joints, shearing is limited to what maximum thickness a) 3/16th inch b) 3/8th inch c) 1/2 inch d) 5/8th inch (15mm) Reference: API-650, Paragraph 4.1.2 ANS: D Q4. What are the requirements regarding mill test reports according to API650? a) No material shall be used in the construction of an AST unless it is accompanied by a mill test report b) Mill test reports are required only on shell plate material c) Mill test reports shall be furnished to the purchaser only when specified in the original purchase order d) Mill test reports shall be furnished to the purchaser prior to final acceptance of the AST Reference: API-650, Paragraph 4.2.1ANS: C
Charlie Chong/ Fion Zhang
Q5. Mill and shop inspection releases the manufacturer from responsibility for replacing defective material. a) True b) False Reference: API-650, Paragraph 4.2.2 ANS: B
Charlie Chong/ Fion Zhang
Answers to API-Standard 650 Section 4, Fabrication
Charlie Chong/ Fion Zhang
Day Break
Charlie Chong/ Fion Zhang
Day Break
Charlie Chong/ Fion Zhang
http://news.xinhuanet.com/english2010/photo/2011-03/31/c_13807187_3.htm
Day Break
Charlie Chong/ Fion Zhang
http://veryfatoldman.blogspot.com/2014/04/singapore-kopitiam-culture.html
Day Break Day Break
Charlie Chong/ Fion Zhang
http://mylovelybluesky.com/2014/03/kedai-kopi-chung-wah/
Charlie Chong/ Fion Zhang
Day Break
Charlie Chong/ Fion Zhang
Day Break
Section 5 – Erection Q1. What welding process is not permitted when impact testing of the material is required? a) Shielded metal-arc b) Gas metal-arc c) Oxyfuel d) Submerged arc Reference: API-650, Paragraph 5.2.1.1 ANS: C Q2. Welding may be performed manually, automatically, or semiautomatically according to the procedures described in ____ of the ASME Code. a) Section VIII, Division 1 b) B31.3 c) Section VIII, Division 2 d) Section IX Reference: API-650, Paragraph 5.2.1.1ANS: D
Charlie Chong/ Fion Zhang
Q3. No welding of any kind shall be performed when the temperature of the base metal is less than ____°F a) Sixty b) Thirty-two c) Zero d) Negative fifteen Reference: API-650, Paragraph 5.2.1.2 ANS: C Q4. When base metal thickness is greater than 1.25 inches or the base metal temperature is 0°F -32°F, what requirement must be met? a) The base metal within 3 inches of the starting point of the welding shall be heated to a temperature warm to the hand (140°F) b) The base metal within 3 inches of the starting point of the welding shall be heated to a temperature of not less than 200°F c) The base metal within 3 inches of the starting point of the welding shall be heated to a temperature of not less than 60°F d) The base metal within 3 inches of the starting point of the welding shall be heated to a temperature of not less than 45°F Reference: API-650, Paragraph 5.2.1.2 ANS: A
Charlie Chong/ Fion Zhang
API653: 10.4.2.3 No welding of any kind shall be performed when the surfaces of the parts to be welded are wet from rain, snow, or ice; when rain or snow is falling on such surfaces; or during periods of high winds unless the welder and the work are properly shielded. No welding of any kind shall be performed when the temperature of the base metal is less than 0 °F. When the temperature of the base metal is between 0 °F and 32 °F or the thickness is in excess of 1 in., the base metal within 3 in. of the place where welding is to be started shall be heated to a temperature warm to the hand (approximately 140 °F) before welding. (See 10.4.4.3 for preheat requirements for shell plates over 1½ in. thick.) 10.4.4.3 For horizontal and vertical joints in tank shell courses constructed of material over 1 ½ in. thick (based on the thickness of the thicker plate at the joint), multi-pass weld procedures are required, with no pass more than 3/4-in. thick permitted. A minimum preheat of 200 °F is required of these welds.
Charlie Chong/ Fion Zhang
Q5. What is the maximum acceptable undercut for horizontal butt joints? a) 1/64th inch b) 1/32nd inch c) 3/64th inch d) 3/32nd inch Reference: API-650, Paragraph 5.2.1.4 ANS: B Q6. What is the maximum acceptable undercut for vertical butt joints? a) 3/32nd inch b) 3/64th inch c) 1/32nd inch d) 1/64th inch Reference: API-650, Paragraph 5.2.1.4 ANS: D
Charlie Chong/ Fion Zhang
Q7. What is the maximum permissible weld reinforcement for a vertical joint in plate thickness 1.25�? a) 3/16th inch b) 1/8th inch c) 1/4th inch d) 3/32nd inch Reference: API-650, Paragraph 5.2.1.5 ANS: A Q8. When tack welds are used during the assembly of vertical joints, what requirement is stipulated by API-650? a) Tack welds that are to be removed do not require a qualified procedure or welder b) Tack welds that are to be left in place shall be made using a qualified procedure only c) Tack welds that are to be removed may be made using a welder in training d) Tack welds that are to be left in place shall be made using a qualified procedure and welder Reference: API-650, Paragraph 5.2.1.8 ANS: D
Charlie Chong/ Fion Zhang
API650: 8.1.3.4 The finished surface of the weld reinforcement at the location of the radiograph shall either be flush with the plate or have a reasonably uniform crown not to exceed the following values:
Charlie Chong/ Fion Zhang
API653: Table 10.1—Maximum Thicknesses on New Welds
Charlie Chong/ Fion Zhang
Q9. What is the requirement when protective coatings are used on surfaces to be welded? a) The coating must be removed prior to welding b) The coating shall be included in the welder’s performance qualification tests c) The coating shall be included in the welding procedure qualification d) The coating shall be identified on the purchase order Reference: API-650, Paragraph 5.2.1.9 ANS: C Q10. The welding of the ____ shall be practically complete prior to weldingout the bottom joints. a) Nozzle reinforcement periphery welds b) Shell-to-bottom weld c) All vertical and horizontal shell welds d) All external attachment welds Reference: API-650, Paragraph 5.2.2.2 ANS: B
Charlie Chong/ Fion Zhang
Q11. In a vertical joint of an AST, what is the maximum misalignment of 1.5” thick plate? a) Maximum misalignment is .150 inch b) Maximum misalignment is .145 inch c) Maximum misalignment is .135 inch d) Maximum misalignment is .125 inch Reference: API-650, Paragraph 5.2.3.1 ANS: D (10% of 1.5” or 1/8”, max) Q12. In a horizontal joint of an AST, what is the maximum projection of an upper plate beyond the face of the plate below it? The plate thickness is .25 inch. a) Maximum projection is .0625 inch b) Maximum projection is .0500 inch c) Maximum projection is .1250 inch d) Maximum projection is .09375 inch Reference: API-650, Paragraph 5.2.3.2 ANS: A, for t<0.312”, P=1/16=0.625”
Charlie Chong/ Fion Zhang
API653: 10.4.4 Shells 10.4.4.1 Plates to be joined by butt welding shall be matched accurately and retained in position during welding. Misalignment in completed vertical joints over 5/8-in. thick shall not exceed 10 % of the plate thickness, with a maximum of 1/8 in. Misalignment in joints 5/8-in. thick or less shall not exceed 1/16 in. Vertical joints shall be completed before the lower horizontal weld is made. 10.4.4.2 In completed horizontal butt joints, the upper plate shall not project beyond the face of the lower plate at any point by more than 20 % of the thickness of the upper plate, with a maximum projection of 1/8 in., except that a projection of 1/16 in. is acceptable for upper plates less than 5/16-in. thick. 10.4.4.3 For horizontal and vertical joints in tank shell courses constructed of material over 1 1/2-in. thick (based on the thickness of the thicker plate at the joint), multi-pass weld procedures are required, with no pass more than 3/4-in. thick permitted. A minimum preheat of 200 째F is required of these welds.
Charlie Chong/ Fion Zhang
Q13. Multi-pass weld procedures are required for circumferential and vertical joints in tank shell courses constructed of material that is more than 1.5 inches thick. What is the maximum weld pass size permitted and what is the minimum pre-heat temperature? a) No weld pass over ¾ inch with a minimum pre-heat of 300°F b) No weld pass over ½ inch with a minimum pre-heat of 200°F c) No weld pass over ¾ inch with a minimum pre-heat of 200°F d) No weld pass over ½ inch with a minimum pre-heat of 300°F Reference: API-650, Paragraph 5.2.3.4 ANS: C 10.4.4.3 For horizontal and vertical joints in tank shell courses constructed of material over 1 1/2-in. thick (based on the thickness of the thicker plate at the joint), multi-pass weld procedures are required, with no pass more than 3/4-in. thick permitted. A minimum preheat of 200 °F is required of these welds.
Charlie Chong/ Fion Zhang
Q14. The initial weld pass inside the shell of the shell-to-bottom weld shall be cleaned and examined for its entire circumference. This examination shall be visually and by which of the following? a) Magnetic particle or ultrasonic or suitable liquid penetrant process b) Magnetic particle or suitable liquid penetrant process or a vacuum box and bubble method c) Magnetic particle or radiography or vacuum box and bubble method d) Magnetic particle or acoustic emission or eddy current Reference: API-650, Paragraph 5.2.4.1 ANS: B
Charlie Chong/ Fion Zhang
Q15. The required examination of the initial weld pass as described in API650 may be waived subject to agreement between the purchaser and the AST manufacturer provided all but which of the following examinations are performed on the entire circumference of the weld(s) a) Examine either side of the finished weld by MT, PT, or right angle vacuum box b) Visually examine the initial weld (inside and outside) c) Visually examine the finished joint welded surfaces (inside and outside the shell) d) Examine either side of the finished weld by MT, PT, UT, or RT Reference: API-650, Paragraph 5.2.4.2 ANS: D
Charlie Chong/ Fion Zhang
Q16. What are the dimensions of a standard vacuum testing box? a) 6” wide by 30” long b) 6” wide by 24” long c) 6” wide by 36” long d) 6” wide by 32” long Reference: API-650, Paragraph 5.3.3.1 ANS: A Q17. In an examination of a tank’s bottom weld seams by vacuum box testing, what is the required partial vacuum pressure? a) At least 1 lbf/in2 gauge (psig) b) At least 2 lbf/in2 gauge (psig) c) At least 3 lbf/in2 gauge (psig) d) At least 4 lbf/in2 gauge (psig) Reference: API-650, Paragraph 5.3.3.4 ANS: C
Charlie Chong/ Fion Zhang
Q18. If an alternative to vacuum box testing is used, whose approval is required? a) The Manufacturer b) The API-653 Inspector c) The local jurisdiction d) The purchaser Reference: API-650, Paragraph 5.3.3.5 ANS: D Q19. After fabrication is completed but prior to filling an aboveground storage tank with test water, reinforcing plates shall be tested. What method of test and pressure shall be used? a) A hydrostatic pressure test at up to 15 lbf/in2 (psig) b) A pneumatic pressure test at up to 15 lbf/in2 (psig) c) A vacuum test at a partial pressure of 2 lbf/in2 (psig) d) A pneumatic pressure test at up to 25 lbf/in2 (psig) Reference: API-650, Paragraph 5.3.5 ANS: B
Charlie Chong/ Fion Zhang
Q20. A new aboveground storage tank must be tested. If water is available for testing the shell, the tank shall be filled to any of the following levels except? a) To the maximum design liquid level b) Tanks with tight roofs, to 2 inches above the weld connecting the roof plate of compression bar to the top angle of the shell c) To overflowing to ensure all air is vented from the tank d) To a level lower than specified in a) or b) when restricted by overflows or freeboard agreement between the manufacturer and the purchaser Reference: API-650, Paragraph 5.3.6 ANS: C
Charlie Chong/ Fion Zhang
API650: 7.3.5 Testing of the Shell After the entire tank and roof structure is completed, the shell (except for the shell of tanks designed in accordance with Annex F) shall be tested by one of the following methods, as specified on the Data Sheet, Line 14. 1) If water is available for testing the shell, the tank shall be filled with water as follows: (1) to the maximum design liquid level, H; (2) for a tank with a tight roof, to 50 mm (2 in.) above the weld connecting the roof plate or compression bar to the top angle or shell; (3) to a level lower than that specified in Sub-item 1 or 2 when restricted by overflows, an internal floating roof, or other freeboard by agreement between the Purchaser and the Manufacturer, or (4) to a level of seawater producing a bottom of shell hoop stress equal to that produced by a full-height fresh water test. The tank shall be inspected frequently during the filling operation, and any welded joints above the test-water level shall be examined in accordance with Item 2 below. This test shall be conducted before permanent external piping is connected to the tank. Attachments to the shell defined in 5.8.1.1, located at least 1 m (3 ft) above the water level, and roof appurtenances may be welded during the filling of the tank. After completion of the hydro-test, only non-structural small attachments may be welded to the tank in accordance with 7.2.1.11.
Charlie Chong/ Fion Zhang
Q21. The purchaser of an AST that is designed to be gas tight required the roof to be tested pneumatically. What maximum pressure would be applied to a tank with ¼” thick roof plates? a) The maximum pneumatic pressure permitted is .053 psi b) The maximum pneumatic pressure permitted is .071 psi c) The maximum pneumatic pressure permitted is .083 psi d) The maximum pneumatic pressure permitted is .091 psi Reference: API-650, Paragraph 5.3.7.1 and 3.10.2.2 Solution: 3/16” thick plate = 7.65 lb/ft ∴1/16” = 2.55 lb/ft ANS: B
Charlie Chong/ Fion Zhang
API650: 7.3.7 Testing of the Roof 7.3.7.1 Upon completion, the roof of a tank designed to be gas-tight (except for roofs designed under 7.3.7.2, F.4.4, and E.7.5) shall be tested by one of the following methods. a) Applying internal air pressure not exceeding the weight of the roof plates and applying to the weld joints a bubble solution or other material suitable for the detection of leaks. b) Vacuum testing the weld joints in accordance with 8.6 to detect any leaks. 7.3.7.2 Upon completion, the roof of a tank not designed to be gastight, such as a tank with peripheral circulation vents or a tank with free or open vents, shall receive only visual examination of its weld joints, unless otherwise specified by the Purchaser.
Charlie Chong/ Fion Zhang
Q22. During the filling of an aboveground storage tank for testing, leakage was observed in a horizontal seam. Repairs are to be completed with the test water in the tank. The tank is 61 feet high and the leak is discovered 29 feet below the top of the tank. Where must the water level be during the repair? a) The water level shall be not less than 30 feet from the top of the tank b) The water level shall be not more than 32 feet from the bottom of the tank c) The water level shall be at the maximum design liquid level d) The water shall be removed from the tank Reference: API-650, Paragraph 5.4.4 ANS:A, 61-29=32â&#x20AC;&#x2122;, answer The water level shall be more than 31 feet from the top of the tank API650: 7.4.4 Repairs of defects discovered after the tank has been filled with water for testing shall be made with the water level at least 0.3 m (1 ft) below any point being repaired or, if repairs have to be made on or near the tank bottom, with the tank empty. Welding shall not be done on any tank unless all connecting lines have been completely blinded. Repairs shall not be attempted on a tank that is filled with oil or that has contained oil until the tank has been emptied, cleaned, and gas freed. Repairs on a tank that has contained oil shall not be attempted by the Manufacturer unless the manner of repair has been approved in writing by the Purchaser and the repairs are made in the presence of the Purchaserâ&#x20AC;&#x2122;s inspector.
Charlie Chong/ Fion Zhang
Q23. A 60 foot high aboveground storage tank is designed with an internal floating roof. What is the maximum out-of-plumbness permitted on the 54.5 foot fixed roof columns? a) 2.94 inches b) 3.27 inches c) 1.31 inches d) 1.18 inches Reference: API-650, Paragraph 5.5.2 ANS:B/ 57.5x12/200 = 3.27, smaller than 5 Q24. What is the maximum roundness tolerance (radius tolerance) permitted on an AST that is 110 feet in diameter and where is this tolerance applied? a) ¾” measured 10 feet above the bottom corner weld b) ¾” measured 1 foot below the top shell angle joint c) ¾” measured 1 foot above the bottom corner weld d) ¾” measured 10 feet below the top shell angle joint Reference: API-650, Paragraph 5.5.3 ANS: C
Charlie Chong/ Fion Zhang
7.5.2 Plumbness a) The maximum out-of-plumbness of the top of the shell relative to the bottom of the shell shall not exceed 1/200 of the total tank height. The out-of-plumbness in one shell course shall not exceed the permissible variations for flatness and waviness as specified in ASTM A6M/A6, ASTM A20M/A20, or ASTM A480M/A480, whichever is applicable. b) The maximum out-of-plumbness of roof columns, guide poles, or other vertical internal components shall not exceed 1/200 of the total height. The 1/200 criteria shall also apply to fixed roof columns. For tanks with internal floating roofs, apply the criteria of this section or Annex H, whichever is more stringent. H.4.5 Roof Penetrations Columns, ladders, and other rigid vertical appurtenances that penetrate the deck shall be provided with a seal that will permit a local deviation of ±125 mm (±5 in.). Appurtenances shall be plumb within a tolerance of ±75 mm (±3 in.).
Charlie Chong/ Fion Zhang
7.5.3 Roundness Radii measured at 0.3 m (1 ft) above the bottom corner weld shall not exceed the following tolerances:
Charlie Chong/ Fion Zhang
Q25. Peaking at vertical welds and banding at horizontal welds shall not exceed ____. a) 1 inch b) ¾ inch c) ½ inch d) ¼ inch Reference: API-650, Paragraph 5.5.4 (a and b) ANS: C Q26. Peaking and banding are determined using a horizontal sweep board for peaking and a straight edge vertical sweep board for banding. What is the required length of these sweep boards? a) 48 inches b) 24 inches c) 42 inches d) 36 inches Reference: API-650, Paragraph 5.5.4 (a and b) ANS: D
Charlie Chong/ Fion Zhang
API650: 7.5.4 Local Deviations Local deviations from the theoretical shape (for example, weld discontinuities and flat spots) shall be limited as follows. a) Deviations (peaking) at vertical weld joints shall not exceed 13 mm (1/2 in.). Peaking at vertical weld joints shall be determined using a horizontal sweep board 900 mm (36 in.) long. The sweep board shall be made to the nominal radius of the tank. b) Deviations (banding) at horizontal weld joints shall not exceed 13 mm (1/2 in.). Banding at horizontal weld joints shall be determined using a straight edge vertical sweep board 900 mm (36 in.) long. c) Flat spots measured in the vertical plane shall not exceed the appropriate plate flatness and waviness requirements given in 7.5.2. API563: 10.5.4 Peaking With a horizontal sweep board 36-in. long, peaking shall not exceed 1/2 in. The sweep board shall be made to the true outside radius of the tank. API563: 10.5.5 Banding With a vertical sweep board 36-in. long, banding shall not exceed 1 in.
Charlie Chong/ Fion Zhang
Horizontal Peaking Board, peaking of vertical weld. Vertical Banding Board, banding of horizontal weld.
Charlie Chong/ Fion Zhang
http://www.naehss.org/PastSchools/2011/LargeTankStorageIntegrity.pdf
Q27. The top of the concrete ringwall (where installed) of an AST must be level within ± 1/8” in any 30 feet of circumference. What is the total circumferential tolerance measured from the average elevation? a) ±1/8” b) ±3/16” c) ±1/2” d) 1/4” Reference API-650, Paragraph 5.5.5.2 (a) ANS: D Q28. Where a concrete ringwall is not provided, the foundation under the shell shall be level to within what tolerances? a) ±1/8” in any 30’ of the circumference and ±1/2” in the total circumference measured from the average elevation b) ±1/8” in any 10’ of the circumference and ±1/2” in the total circumference measured from the average elevation c) ±1/8” in any 10’ of the circumference and ±1/4” in the total circumference measured from the average elevation d) ±1/8” in any 30’ of the circumference and ±1/4” in the total circumference measured from the average elevation Reference API-650, Paragraph 5.5.5.2 (b) ANS: B
Charlie Chong/ Fion Zhang
Q29. For foundations specified to be sloped from a horizontal plane, the actual elevation shall not deviate from the calculated differences by more than which of the following where concrete ringwalls are provided? a) ±1/8” in any 30’ of the circumference and ±1/4” in the total circumference measured from the average elevation b) ±1/8” in any 10’ of the circumference and ±1/2” in the total circumference c) ±1/8” in any 10’ of the circumference and ±1/2” in the total circumference measured from the average elevation d) ±1/8” in any 30’ of the circumference and ±1/4” in the total circumference Reference API-650, Paragraph 5.5.5.3 (a) ANS: D
Charlie Chong/ Fion Zhang
Q30. For foundations specified to be sloped from a horizontal plane, the actual elevation shall not deviate from the calculated differences by more than which of the following where concrete ringwalls are not provided? a) ±1/8” in any 30’ of the circumference and ±1/2” in the total circumference measured from the average elevation b) ±1/8” in any 10’ of the circumference and ±1/2” in the total circumference c) ±1/8” in any 10’ of the circumference and ±1/4” in the total circumference measured from the average elevation d) ±1/8” in any 30’ of the circumference and ±1/4” in the total circumference Reference API-650, Paragraph 5.5.5.3 (b) ANS: B
Charlie Chong/ Fion Zhang
Answers to API-Standard 650 Section 5, Erection
Charlie Chong/ Fion Zhang
Section 6 â&#x20AC;&#x201C; Methods of inspecting Joints Q1. With regards to radiographic examination of welded joints, API-650 considers plates to be the same thickness when the difference in their specified or design thickness is not greater than ____. a) 1/32nd inch b) 1/16th inch c) 3/32nd inch d) 1/8th inch Reference: API-650, Paragraph 6.1 ANS: D API650: 8.1 Radiographic Method For the purposes of this paragraph, plates shall be considered of the same thickness when the difference in their specified or design thickness does not exceed 3 mm (1/8 in.).
Charlie Chong/ Fion Zhang
Q2. Which of the following joints do not require radiographic examination? a) Bottom-plate welds b) Shell butt welds c) Flush-type connections with butt welds d) Annular-plate butt welds Reference: API-650, Paragraph 6.1.1 ANS: A Q3. Vertical butt welds in plates not greater than 3/8th inch thick, require one spot radiograph to be taken in the first _____ of completed vertical joint of each type and thickness by each welder or welding operator. a) 100 feet b) 50 feet c) 25 feet d) 10 feet Reference: API-650, Paragraph 6.1.2.2(a) ANS: D
Charlie Chong/ Fion Zhang
Q4. One additional spot radiograph shall be taken in each additional ____ of vertical joint of the same type and thickness. a) 10 feet b) 200 feet c) 100 feet d) 25 feet Reference: API-650, Paragraph 6.1.2.2(a) ANS: C Q5. What percentage of the selected spot radiographs must be at junctions of vertical and horizontal welded joints? a) 25 percent b) 50 percent c) 75 percent d) 15 percent Reference: API-650, Paragraph 6.1.2.2(a) ANS: A
Charlie Chong/ Fion Zhang
Q6. For butt welded joints in plates over 3/8” to not over 1” in thickness are required to be radiographically examined to the same extent as plates 3/8” and less. What additional spot examination does API-650 require for these welded joints? a) 50 percent of all vertical and horizontal junctions b) 75 percent of all vertical and horizontal junctions c) 100 percent of all vertical and horizontal junctions d) 25 percent of all horizontal joints between the first and second course Reference: API-650, Paragraph 6.1.2.2(b) ANS: C Q7. The radiographic film for all junctions of vertical and horizontal joints shall show at least ____ of weld length on each side of the vertical intersection. a) 3 inches b) 2 inches c) 1 inch d) 4 inches Reference: API-650, Paragraph 6.1.2.2(b) and (c) ANS: B
Charlie Chong/ Fion Zhang
API650: 8.1.2.2 b) For butt-welded joints in which the thinner shell plate is greater than 10 mm (3/8 in.) but less than or equal to 25 mm (1 in.) in thickness, spot radiographs shall be taken according to Item a. In addition, all junctions of vertical and horizontal joints in plates in this thickness range shall be radiographed; each film shall clearly show not less than 75 mm (3 in.) of vertical weld and 50 mm (2 in.) of weld length on each side of the vertical intersection. In the lowest course, two spot radiographs shall be taken in each vertical joint: one of the radiographs shall be as close to the bottom as is practicable, and the other shall be taken at random (see the center panel of Figure 8.1).
Charlie Chong/ Fion Zhang
Q8. The butt weld around the periphery of an insert manhole or nozzle shall be ____. a) Completely examined by liquid penetrant methods b) Completely examined by ultrasonic methods c) Completely examined by magnetic particle methods d) Completely examined by radiographic methods Reference: API-650, Paragraph 6.1.2.2(d) ANS: D Q9. After the initial spot radiograph in the first 10 feet of horizontal butt joint, additional spot radiographs shall be taken at what increment? a) One radiograph shall be taken in each additional 200 feet b) One radiograph shall be taken in each additional 100 feet c) One radiograph shall be taken in each additional 300 feet d) One radiograph shall be taken in each additional 150 feet Reference: API-650, Paragraph 6.1.2.3 ANS: A
Charlie Chong/ Fion Zhang
Q10. What is the minimum weld length that must be clearly shown on each radiograph? a) 2 inches b) 3 inches c) 6 inches d) 8 inches Reference: API-650, Paragraph 6.1.2.8 ANS: C Q11. Personnel who perform and evaluate radiographic examinations according to API-650 shall be qualified and certified by the manufacturer as meeting the requirements as generally outlined in _____. a) Level II or Level III of ASNT SNAT-TC-1B b) Level II or Level III of ASNT SNT-TC-1B c) Level II or Level III of ASNT SNAT-TC-1A d) Level II or Level III of ASNT SNT-TC-1A Reference: API-650, Paragraph 6.1.3.2ANS: D
Charlie Chong/ Fion Zhang
Q12. The acceptance standards for radiographic examinations shall be in accordance with which of the following? a) Paragraph UW-51(b) in Section VIII of the ASME Code b) Paragraph PW-51(b) in Section I of the ASME Code c) Paragraph 341.3.2 in B31.3 Process Piping of the ASME Code d) Paragraph RB-3233 in the National Board Inspection Code (NBIC) Reference: API-650, Paragraph 6.1.5 ANS: A Q13. If a section of weld is shown by a radiograph to be unacceptable under the provisions of API-650, paragraph 6.1.5 or the radiograph does not define the limits of the deficient welding, which of the following requirements apply? a) One additional spot shall be taken and at least 3â&#x20AC;? of weld shall be represented b) Two spots adjacent to the section shall be examined by radiography c) Two spots ten feet from each side of the original radiography shall be examined d) Two spots, chosen randomly by the purchaserâ&#x20AC;&#x2122;s inspector, shall be examined by radiography Reference API-650, Paragraph 6.1.6 ANS: B
Charlie Chong/ Fion Zhang
API650: 8.1.6 Determination of Limits of Defective Welding When a section of weld is shown by a radiograph to be unacceptable under the provisions of 8.1.5 or the limits of the deficient welding are not defined by the radiograph, two spots adjacent to the section shall be examined by radiography; however, if the original radiograph shows at least 75 mm (3 in.) of acceptable weld between the defect and any one edge of the film, an additional radiograph need not be taken of the weld on that side of the defect.
Charlie Chong/ Fion Zhang
Q14. After an aboveground storage tank is completed, what shall be done with the radiographs? a) They shall become the property of the insurance company b) They shall become the property of the manufacturer c) They shall become the property of the purchaser d) They shall become the property of the API Reference API-650, Paragraph 6.1.8.2 ANS: C Q15. According to API-650, magnetic particle examination shall be performed to a written procedure. The examiner shall have his/her vision checked and be able to read which of the following? a) The magnetic particle written procedure at a distance not less than 12 inches b) A Jaeger Type 3 standard chart at a distance not less than 12 inches c) A Jaeger Type 1 standard chart at a distance not less than 12 inches d) A Jaeger Type 2 standard chart at a distance not less than 12 inches Reference API-650, Paragraph 6.2.2 and 6.2.3 (a) ANS: D
Charlie Chong/ Fion Zhang
Q16. Ultrasonic examination shall be performed in accordance with a written procedure. Examiners shall be qualified and certified by the manufacturer as meeting the requirements of certification as generally outlined in which of the following? a) Level II or Level III of ASNT SNAT-TC-1B b) Level II or Level III of ASNT SNT-TC-1B c) Level II or Level III of ASNT SNAT-TC-1A d) Level II or Level III of ASNT SNT-TC-1A Reference API-650, Paragraph 6.3.2 and 6.3.3 ANS: D
Charlie Chong/ Fion Zhang
Q17. Liquid penetrant examination shall be performed in accordance with a written procedure. The examiner shall have his/her vision checked and be able to read which of the following? a) The liquid penetrant written procedure at a distance not less than 12 inches b) A Jaeger Type 2 standard chart at a distance not less than 12 inches c) A Jaeger Type 1 standard chart at a distance not less than 12 inches d) A Jaeger Type 3 standard chart at a distance not less than 12 inches Reference API-650, Paragraph 6.4.2 and 6.4.3 (a) ANS: B
Charlie Chong/ Fion Zhang
Q18. Undercutting of welds attaching nozzles, manholes, cleanout openings, and permanent attachments shall not exceed which of the following? a) Undercutting shall not exceed 1/64th inch b) Undercutting shall not exceed 3/32nd inch c) Undercutting shall not exceed 1/32nd inch d) Undercutting shall not exceed 3/64th inch Reference API-650, Paragraph 6.5.1 (b) ANS: A
Charlie Chong/ Fion Zhang
Answers to API-Standard 650 Section 6, Methods of Inspecting Joints
Charlie Chong/ Fion Zhang
Section 7 – Welding Procedure and Welder Qualifications Q1. Who is responsible for preparing the welding procedure specification, performing the qualification tests, and preparing the procedure qualification record? a) The welding operator or welder b) The purchaser’s inspector c) The purchaser’s welding engineer d) The erection manufacturer or the fabrication manufacturer if other than the erection manufacturer Reference API-650, Paragraph 7.2.1.1 ANS: D
Charlie Chong/ Fion Zhang
Q2. The manufacturer has the approval of the purchaser to use a material listed in API-650 but not included in the applicable table of ASME Section IX. What Group number would this material be included in if the minimum tensile strength is specified at 73,000 psi? a) This material would be included in Group number 2 b) This material would be included in Group number 1 c) This material would be included in Group number 3 d) This material can not be used in AST construction Reference API-650, Paragraph 7.2.1.3 ANS: A
Charlie Chong/ Fion Zhang
API650: 9.2.1.3 Material specifications listed in Section 4 of this standard but not included in Table QW-422 of Section IX of the ASME Code shall be considered as P-No. 1 material with group numbers assigned as follows according to the minimum tensile strength specified: a) less than 485 MPa (70 ksi)—Group 1; b) equal to or greater than 485 MPa (70 ksi) but less than 550 MPa (80 ksi)— Group 2; c) equal to or greater than 550 MPa (80 ksi)—Group 3. Separate welding procedures and performance qualifications shall be conducted for A841M/A841 material.
Charlie Chong/ Fion Zhang
Q3. When impact tests of the heat-affected zone are required, how shall this requirement be treated? a) Heat treated condition of the base metal shall be a non-essential variable b) Heat treated condition of the base metal shall be an essential variable c) Heat treated condition of the base metal shall be a supplementary essential variable d) Heat treated condition of the base metal does not need to be addressed on the welding procedure specification Reference API-650, Paragraph 7.2.1.4ANS: C
Charlie Chong/ Fion Zhang
Q4. If a protective coating has been applied to weld edge preparations, how is this condition treated on the welding procedure specification? a) The coating shall be removed and does not affect the weld and therefore does not need to be addressed b) The coating shall be included as an essential variable c) The coating shall be included as a non-essential variable d) The coating shall be included as a supplementary essential variable Reference API-650, Paragraph 7.2.1.4 ANS: B
Charlie Chong/ Fion Zhang
Q5. Materials to be used at a design metal temperature below ____, the qualification of the welding procedure for vertical joints shall include impact tests of the weld metal. a) 50°F (10°C) b) 32°F c) 60°F d) 0°F Reference API-650, Paragraph 7.2.2.3 ANS: A Q6. Welder qualification tests conducted by one manufacturer shall not qualify a welder or welding operator to do work for another manufacturer. a) True b) False Reference API-650, Paragraph 7.3.1 ANS: A
Charlie Chong/ Fion Zhang
API650: 9.2.2.3 For all materials to be used at a design metal temperature below 10째C (50째F), the qualification of the welding procedure for vertical joints shall include impact tests of the weld metal. If vertical joints are to be made by a machine, automatic, or semiautomatic process, impact tests of the heataffected zone shall also be made.
Charlie Chong/ Fion Zhang
Q7. Traceability to a welder or welding operator, either by welder’s identification stamp or “weld map”, is required on all but which of the following? a) Shell horizontal weld joints b) Shell vertical weld joints c) Annular plate butt welds (when annular plates are required) d) Roof plate welds and flange-to-nozzle neck welds Reference API-650, Paragraph 7.4 ANS: D
Charlie Chong/ Fion Zhang
Answers to API-Standard 650 Section 7, Welding Procedure and Welder Qualifications
Charlie Chong/ Fion Zhang
Break of the day
Charlie Chong/ Fion Zhang
Break of the day
Charlie Chong/ Fion Zhang
Break of the day
Charlie Chong/ Fion Zhang
Break of the day
Charlie Chong/ Fion Zhang
Break of the day
http://fatboo.com/2011/01/braddell-roti-prata.html
Charlie Chong/ Fion Zhang
Section 8 - Marking Q1. A nameplate shall identify aboveground storage tanks made in accordance with API-650. Where must this nameplate be located on the completed tank? a) This nameplate shall be attached to the tank shell adjacent to a manhole or to a manhole reinforcing plate immediately to the right of the manhole b) This nameplate shall be attached to the tank shell adjacent to a vertical weld joint at least 48â&#x20AC;? above the shell-to-bottom weld joint c) This nameplate shall be attached to the tank shell adjacent to a manhole or to a manhole reinforcing plate immediately above the manhole d) This nameplate shall be attached to the tank shell adjacent to a manhole or to a manhole reinforcing plate immediately below the manhole Reference API-650, Paragraph 8.1.2 ANS: C
Charlie Chong/ Fion Zhang
Q2. The manufacturer of an AST is required to certify to the purchaser that the tank has been constructed in accordance with API-650. How is this certification accomplished? a) The manufacturer shall provide the purchaser with a U-1 Data Report form b) The manufacturer shall provide the purchaser with letter c) The manufacturer shall provide the purchaser with an ASME acceptable “Certificate of Compliance” d) The manufacturer shall provide the purchaser with a notarized certificate of compliance Reference API-650, Paragraph 8.3 ANS: B API650: 10.3 Certification The Manufacturer shall certify to the Purchaser, by a letter such as that shown in Figure 10.2, that the tank has been constructed in accordance with the applicable requirements of this standard. An as-built data sheet in accordance with Annex L shall be attached to the certification letter. NOTE At the Purchaser’s request or at the erection Manufacturer’s discretion, additional pertinent information may be shown on the nameplate, and the size of the nameplate may be increased proportionately.
Charlie Chong/ Fion Zhang
Answers to API-Standard 650 Section 8, Marking
Charlie Chong/ Fion Zhang
Appendix A â&#x20AC;&#x201C; Optional Design Basis for Small Tanks Q1. What is the maximum shell thickness including corrosion allowance permitted for tanks that comply Appendix A of API-650? a) 7/8th inch b) 3/4th inch c) 5/8th inch d) 1/2 inch Reference API-650, Paragraph A.2.1ANS: D Q2. What is the maximum tensile strength, before the joint efficiency is applied, permitted in the design of small tanks in accordance with Appendix A of API-650? a) 21000 psi b) 21500 psi c) 21000 ksi d) 21500 ksi Reference API-650, Paragraph A.3.1 ANS:A
Charlie Chong/ Fion Zhang
Q3. When computing the tension in each ring (course) of a small tank designed in accordance with Appendix A of API-650, where is this tension computed? a) The tension shall be computed 12 inches above the centerline of the course in question b) The tension shall be computed 12 inches above the centerline of the lower horizontal joint of the course in question c) The tension shall be computed 12 inches above the centerline of the tank in question d) The tension shall be computed 12 inches below the centerline of the upper horizontal joint of the course in question Reference API-650, Paragraph A.3.3 ANS: B Q4. What joint efficiency factor shall be used in the design of small tanks designed in accordance with Appendix A of API-650 when spot radiographic examination is applied? a) 1.00 b) 0.90 c) 0.85 d) 0.70 Reference API-650, Paragraph A.3.4 ANS: C
Charlie Chong/ Fion Zhang
5. What joint efficiency factor shall be used in the design of small tanks designed in accordance with Appendix A of API-650 when spot radiographic examination is omitted? a) 1.00 b) 0.90 c) 0.85 d) 0.70 Reference API-650, Paragraph A.3.4 ANS: D
Charlie Chong/ Fion Zhang
Answers to API-Standard 650 Appendix A - Optional Design Basis for Small Tanks
Charlie Chong/ Fion Zhang
API 651- CATHODIC PROTECTION QUESTIONS Section 4 - Corrosion of Above Ground Steel Storage Tanks Q1. According to API Recommended Practice - 651, there are four components in each corrosion cell. Theses components are an anode and all but which of the following? a) DC current supplied by batteries b) A cathode c) A metallic path connecting the anode and cathode d) An electrolyte Reference: API-651 Paragraph 4.1.1 ANS: A
Charlie Chong/ Fion Zhang
Q2. The base metal goes into solution (corrodes) by releasing electrons and forming positive metal ions. This statement describes what takes place at what component of a corrosion cell? a) The cathode b) The electrolyte c) The metallic connection between the cathode and the anode d) The anode Reference: API-651 Paragraph 4.1.1(a) ANS: D Q3. Which of the following is the most correct statement regarding the cathode? a) Moderate corrosion takes place at the cathode b) No corrosion takes place at the cathode c) All corrosion takes place at the cathode d) A chemical reaction takes place using electrons released at the electrolyte Reference: API-651 Paragraph 4.1.1(b) ANS: B
Charlie Chong/ Fion Zhang
Q4. The electrolyte contains ions and conducts positive current from the anode to the cathode. The most common electrolyte for external tank bottom surfaces is ____, while the most common for internal surfaces is ____. a) Water, sludge and moist soil b) Moist soil, water and sludge c) Acidic soil, water and sludge d) Moist soil, product and sludge Reference: API-651 Paragraph 4.1.1(d) ANS: B Q5. The two most common types of corrosion to tank bottoms are ______ and ______. a) Stress corrosion and galvanic b) Erosion and erosion/corrosion c) General and pitting d) Stray current and bimetallic Reference: API-651 Paragraph 4.1.2 ANS: C
Charlie Chong/ Fion Zhang
Q6. Which type of corrosion results in relatively uniform metal loss? a) Erosion and erosion/corrosion b) Stray current c) General d) Pitting Reference: API-651 Paragraph 4.1.2 ANS: C Q7. Which type of corrosion may only affect relatively small areas, while substantial areas of the surface are unaffected by corrosion? a) Galvanic b) General c) Brittle d) Pitting Reference: API-651 Paragraph 4.1.2 ANS: D
Charlie Chong/ Fion Zhang
Q8. Composition of the metal is a factor in determining which areas become anodes and which become cathodes. What else can cause corrosion? a) Differences between weld metal, heat affected zone, and parent metal b) Differences in thickness between adjacent plates c) Improper fit-up of the welded joint d) Slag inclusion in the weld metal Reference: API-651 Paragraph 4.1.3 ANS: A
Charlie Chong/ Fion Zhang
Q9. Which of the following is a correct statement regarding oxygen concentration of the electrolyte. a) Oxygen concentration in the electrolyte has no impact on the corrosion cell b) Areas of lower oxygen concentrations become anodic and areas of higher concentrations become cathodic. c) Areas of lower oxygen concentrations become cathodic and areas of higher concentrations become anodic d) Areas of lower oxygen concentrations become acidic and areas of higher concentrations become alkaline Reference: API-651 Paragraph 4.1.4 ANS: B
Charlie Chong/ Fion Zhang
http://www2.ucdsb.on.ca/tiss/stretton/chem2/corrosion.html
Oxygen Concentration Corrosion 2H2O → 2OH- + 2H+ Fe → Fe2+ + 2eFe 2+ + 2OH- → Fe(OH)2 2e- + 2H+ + ½ O2 → H2O
Charlie Chong/ Fion Zhang
http://alchetron.com/RUSTING-OF-IRON-2146-W
Oxygen Concentration Corrosion 2H2O → 2OH- + 2H+ Fe → Fe2+ + 2eFe 2+ + 2OH- → Fe(OH)2 2e- + 2H+ + ½ O2 → H2O 2OH2H+
2e-
Charlie Chong/ Fion Zhang
http://alchetron.com/RUSTING-OF-IRON-2146-W
Charlie Chong/ Fion Zhang
http://imgarcade.com/1/shame-on-you-obama/
Charlie Chong/ Fion Zhang
Q10. Soil characteristics substantially affect what? a) What type of product may be stored in the tank b) What the maximum fill height of the tank is c) The type and rate of corrosion on a structure in contact with soil d) Perk rate for dissipation of small leaks from the tank bottom Reference: API-651 Paragraph 4.1.5 ANS: C Q11. What is another term used for "stray currents"? a) Short circuits b) Positive currents c) Impressed currents d) Interference currents Reference: API-651 Paragraph 4.2.1 ANS: D
Charlie Chong/ Fion Zhang
Q12. The most common and potentially the most damaging stray currents are: a) Direct currents b) Alternating currents c) Intermittent currents d) Close proximity alternating currents Reference: API-651 Paragraph 4.2.1 ANS: A Q13. Which of the following is not likely to be a source of stray currents? a) Static electricity b) Welding machines c) Impressed current cathodic protection systems d) Railroads Reference: API-651 Paragraph 4.2.1 ANS: A
Charlie Chong/ Fion Zhang
Q14. Two metals with different compositions connected in an electrolyte is a general description of: a) A battery b) A current suppressor c) A short circuit d) Galvanic corrosion Reference: API-651 Paragraph 4.2.2 ANS: D Q15. All but one of the following is listed as major factors which influence the severity of internal corrosion. Which is not a factor? a) The pH level of the fluid in contact with the steel bottom b) The amount of nitrogen in the fluid in contact with the steel bottom c) Suspended solids in the fluid in contact with the steel bottom d) Conductivity of the fluid in contact with the steel bottom Reference: API-651 Paragraph 4.2.3 ANS: B
Charlie Chong/ Fion Zhang
Q16. Three major types of internal corrosion to be considered are general corrosion, pitting corrosion, and to a lesser extent in tanks, environmental cracking. a) True b) False Reference: API-651 Paragraph 4.2.3 ANS: A
Charlie Chong/ Fion Zhang
Answers to API-651 Section 4, corrosion of Aboveground Steel Storage Tanks
Charlie Chong/ Fion Zhang
Section 5 - Determination of Need for Cathodic Protection Q1. API Recommended Practice 651 states that the need for cathodic protection must be determined for all storage facilities. Decisions governing the need for cathodic protection should be based on all but which of the following? a) Data from corrosion surveys and operating records b) National Board and ASME recommendations c) Prior test results with similar systems in similar environments d) National, state, and local code requirements and the recommendations in API-651 Reference: API RP 651, Paragraph 5.1 ANS: B
Charlie Chong/ Fion Zhang
Q2. When should corrosion control by cathodic protection for new ASTs be provided? a) After final welding and before hydrostatic testing b) After all stress relief has been carried out c) In the initial design d) After the tank is in service for 6 months Reference: API RP 651, Paragraph 5.1.1ANS: C Q3. Generally tanks in petroleum service use ______ on the internal surfaces to control internal corrosion. a) AC Current instead of DC current cathodic protection systems b) Coatings c) Cathodic protection in conjunction with coatings d) Since pure hydrocarbon fluids are usually not corrosive experience shows that internal corrosion will never occur therefore, corrosion control is not necessary Reference: API RP 651, Paragraph 5.1.3 ANS: B
Charlie Chong/ Fion Zhang
Q4. Cathodic protection is an effective means of corrosion control only if it is possible to pass electrical current between what two components? a) Anode and cathode b) Tank shell and roof support system c) Roof to bottom through roof support structures d) Tank shell and tank bottom Reference: API RP 651, Paragraph 5.1.4ANS: A Q5. A full evaluation of tank history should be performed prior to _______. a) Filling the tank for the 25th time b) Painting the exterior surface of the tank c) Temporarily removing the tank from service d) Determining the need for cathodic protection Reference: API RP 651, Paragraph 5.2.1 ANS: D
Charlie Chong/ Fion Zhang
Q6. Such items as site plan, soil properties, previous repairs, existing cathodic protection of nearby structures, maintenance history, and expected life should be investigated and determined when conducting the ____________. a) Evaluation of the location of a refinery b) Probability study of tank settlement c) Evaluation of tank design/construction history d) Evaluation of tank repairs and alterations Reference: API RP 651, Paragraph 5.2.1.1ANS: C Q7. Of the following items which is not an item that should be investigated and determined in the evaluation of types of service? a) Type of product stored b) Product temperature c) Ambient temperature d) Presence and depth f water bottoms Reference: API RP 651, Paragraph 5.2.1.2 ANS: C
Charlie Chong/ Fion Zhang
Q8. Such items as tank inspections per API Standard 653, corrosion rate records, stray current problems, design and performance of previous protection systems, and structure-to-soil potential surveys should be investigated and determined when conducting the ______. a) Evaluation of tank repair/alteration/construction history b) Evaluation of tank design/construction history c) Evaluation of types of service d) Evaluation of inspection/corrosion history Reference: API RP 651, Paragraph 5.2.1.3ANS: D Q9. The cushion material under the tank has a significant effect on external corrosion of the tank bottom. The material can also influence: a) The effectiveness and applicability of external cathodic protection b) The effectiveness and applicability of internal cathodic protection c) The decision to use or not use a rectifier or DC generator set to supply current d) The type of product that may be stored in the tank Reference: API RP 651, Paragraph 5.3.1.1 ANS: A
Charlie Chong/ Fion Zhang
Q10. What is an advantage of using fine particles for the cushion material? a) The fine particles should be uniform which makes it easier to transport b) Fine particles provide a more dense cushion to help reduce the influx and outflow of oxygen c) Fine particles will not permit the passage of product should a leak occur in the tank bottom d) Fine particles will hold moisture longer permitting it to stabilize and prevent acid from forming in the electrolyte Reference: API RP 651, Paragraph 5.3.1.1 ANS: B Q11. What is the main disadvantage in using large size particles in the soil cushion material? a) The large particles may puncture the tank bottom b) The large particles may trap moisture and allow general corrosion to form c) If large particles are used, differential aeration corrosion may result where the particles contact the tank bottom d) The large particles are more difficult to transport Reference: API RP 651, Paragraph 5.3.1.1ANS: C
Charlie Chong/ Fion Zhang
Q12. A soil resistivity of about 1250 OHM-CM would indicate the soil is probably ____. a) Mildly corrosive 2000-10000 b) Very corrosive <500 c) Corrosive 500-1000 d) Moderately corrosive 1000-2000 Reference: API RP 651, Paragraph 5.3.1.2ANS:D, >10000 less corrosive Q13. The results of soil resistivity surveys can be used to determine ________. a) When it is time to replace the cushion material under the tank bottom b) The need for cathodic protection c) The amount of compression of the cushion material under the tank d) The best place to install a corrosion test bed Reference: API RP 651, Paragraph 5.3.1.2 ANS: B
Charlie Chong/ Fion Zhang
Table 1â&#x20AC;&#x201D;General Classification of Resistivity
Charlie Chong/ Fion Zhang
Q14. A properly designed concrete tank cushion constructed on stable, properly prepared subsoil may be effective in all but which of the following? a) Cracks in the tank bottom weld seams b) Intrusion of groundwater c) Soil-side corrosion d) The need for cathodic protection Reference: API RP 651, Paragraph 5.3.2.1ANS: A Q15. Cracks through the concrete cushion may permit water and contaminants to permeate to the steel tank bottom and provide a path for proper electrical current flow. a) True b) False Reference: API RP 651, Paragraph 5.3.2.1 ANS: B
Charlie Chong/ Fion Zhang
Q16. Corrosion of the steel tank bottom installed on a concrete cushion may result from moisture accumulation caused by all but which of the following? a) Condensation b) Blowing snow or rain c) Humidity in the air surrounding the tank d) Flooding Reference: API RP 651, Paragraph 5.3.2.2 ANS: C
Charlie Chong/ Fion Zhang
Q17. Why would it be more important to provide proper support under cushions of new asphalt than for concrete? a) Asphalt is inherently alkaline and therefore does not have the potential of preventing corrosion b) Asphalt is not inherently alkaline and therefore does not have the potential of preventing corrosion c) Asphalt may degrade and become a corrosive substance d) Asphalt may crack allowing moisture to reach the tank bottom where it will react violently with the asphalt and the steel tank bottom Reference: API RP 651, Paragraph 5.3.3.1ANS: B
Charlie Chong/ Fion Zhang
API651: 5.3.6 Continuous Asphalt Pad A pad of new asphalt may provide many of the same advantages and disadvantages as a concrete pad for reducing corrosion and eliminating the need for cathodic protection. Proper support to prevent cracks and to prevent accumulation of water between the pad and the tank bottom is an important consideration. Asphalt degrades with time and can provide a path for water and dissolved contaminants to come into contact with the steel tank bottom, allowing corrosion to occur. Cathodic protection, if applied, may or may not aid in stopping corrosion when the asphalt becomes deteriorated. In fact, deteriorated asphalt may shield cathodic protection current in a manner similar to a disbonded coating on a pipeline. The condition of the external surface of the tank bottom as well as the asphalt can be determined if coupons are cut from the tank bottom. For new tank construction, use of asphalt pads is discouraged.
Charlie Chong/ Fion Zhang
API651: 5.3.4 Crushed Limestone or Clam Shell Pad In certain locations, the tank pad could consist of a layer of crushed limestone or clam shells. Such tank pads without the use of cathodic protection have produced mixed results. The tank pad should be fine and uniform, since differential aeration corrosion cells will cause pitting at contact areas between the large particles and the metal. The intrusion of water from rain or groundwater makes the environment under the tank alkaline, which may reduce corrosion. If contaminants are present in the pad, or with time infiltrate the pad, corrosion may accelerate. Thus, the use of crushed limestone or clam shells does not clearly eliminate the need for cathodic protection.
Charlie Chong/ Fion Zhang
Q18. How can the condition of the external surface of tank bottom and the asphalt cushion be determined? a) Raise the entire tank and inspect the tank bottom and the asphalt b) Take a core sample from the asphalt for testing. This test will reveal the amount of steel that has gone into solution and been trapped in the asphalt c) Conduct a soil resistivity survey around the periphery of the tank containment d) By cutting coupons from the tank bottom Reference: API RP 651, Paragraph 5.3.3.2 ANS: D Q19. A soil analysis reveals the pH of a native soil cushion to be 6.25. This soil is considered to be: a) Moderately corrosive b) Mildly corrosive (the least of the multiple choice) c) Corrosive d) Very corrosive Reference: API RP 651, Paragraph 5.3.4.1 and Table 2 ANS: B
Charlie Chong/ Fion Zhang
API651: 5.3.2.1 Sand Pad Material The following are issues to sand pad material. g) Measuring pH indicates the hydrogen ion content of a soil. Corrosion of steel is fairly independent of pH when it is in the range of 5.0 to 8.0. The rate of corrosion increases appreciably when pH is < 5.0 and decreases when pH is > 8.0. pH may be determined in accordance with ASTM G51 or equivalent.
Charlie Chong/ Fion Zhang
Q20. A soil analysis reveals the sulfates level of a native soil cushion to be 5525ppm. This soil is considered to be a) Moderately corrosive b) Mildly corrosive c) Corrosive d) Very corrosive Reference: API RP 651, Paragraph 5.3.4.1 and Table 2ANS: D Q21. What is the most common material used as a cushion beneath storage tank bottoms? a) Clean concrete b) Clean sand c) Clean Asphalt d) Clean modified aggregate Reference: API RP 651, Paragraph 5.3.5 ANS: B
Charlie Chong/ Fion Zhang
Q22. The use of oiled sand beneath tank bottoms does not eliminate the need for cathodic protection and in fact may cause cathodic protection to be less effective because: a) The oiled sand has higher resistivity (outcome) b) The sand is unable to conduct electrical current c) The oil acts as an insulator and blocks all current flow (root cause) d) The oil creates a vapor bearer entrapping water and contaminants next to the tank bottom Reference: API RP 651, Paragraph 5.3.5 ANS: A 5.3.5 Oiled Sand Pad Historically, in some cases oil has been added to the sand for various reasons, including compaction and corrosion control. However, if cathodic protection is applied, the higher resistivity of oiled sand may prevent it from being effective. For new tank construction, use of oiled sand is discouraged.
Charlie Chong/ Fion Zhang
Q23. There are several ways the tank cushion can become contaminated. Three of the following are methods of cushion contamination, which one is not? a) In coastal areas salt spay may be washed down the side of the tank b) Fertilizer from spraying operations in rural areas c) Airborne chemicals from industrial operations d) Residual build-up of electrons in the sand cushion Reference: API RP 651, Paragraph 5.3.6.1 ANS: D
Charlie Chong/ Fion Zhang
Q24. Leakage of product from the tank bottom can cause accelerated corrosion by creating ____. a) Stray current corrosion b) Corrosion cells where none existed before c) More positively charged electrons d) A film that would block electrical current flow Reference: API RP 651, Paragraph 5.3.6.2 ANS: B Q25. When a layer of crushed-limestone or clam-shell is used for the tank cushion, why is it important to ensure the particles are fine and uniform? a) Large particles could puncture the tank bottom b) Differential aeration corrosion cells will cause pitting at contact areas between the large particles and the metal c) Large particles may allow the formation of dissolved gas pockets which could become a hazard if hot tap work is performed on the tank bottom d) Large particle will eventually fracture and create voids in the tank cushion Reference: API RP 651, Paragraph 5.3.7 ANS: B
Charlie Chong/ Fion Zhang
Q26. What is an advantage of using crushed-limestone or clam-shell under tank bottoms? a) This material is plentiful and relatively inexpensive b) Contamination is easier to detect because of discoloration c) Water from rain or groundwater makes the environment under the tank alkaline, which may reduce corrosion d) The use of this material eliminates the need for cathodic protection Reference: API RP 651, Paragraph 5.3.7 ANS: C Q27. Heated tanks or tanks storing hot product can cause: a) Increased water intrusion due to causing snow to melt and run down the tank sides b) Excessive drying out of concrete foundations resulting in premature deterioration and failure c) Accelerated corrosion on the internal surface especially in tanks with water bottoms d) Accelerated corrosion on the external surface due to elevated temperature is the area is wet Reference: API RP 651, Paragraph 5.4.1 ANS: D
Charlie Chong/ Fion Zhang
API651: 5.4 Other Factors Affecting Cathodic Protection 5.4.1 Contents of Tank Aboveground storage tank temperature can influence corrosion on tank bottoms. Accelerated corrosion can occur on the external surface of the bottom of heated tanks due to elevated temperatures if the area is wet. NOTE The corrosion rate of steel may double with every 18 째F (10 째C) increase in temperature above 77 째F (25 째C). Aboveground storage tanks containing products above ambient temperature may require an increase in cathodic protection design current density to achieve adequate protection on the external surface of the bottom. Conversely, sufficient heat could dry out a well-drained tank pad, thus, increasing its resistivity and reducing performance of cathodic protection. However, tank operators should be aware that if water penetrates the previously dried out tank pad (such as: flooding, condensation, blowing rain or snow, poor drainage, rooftop water), the resistivity of the tank pad can decrease, developing a more corrosive condition. For this situation, the installation of a cathodic protection system should be installed.
Charlie Chong/ Fion Zhang
Q29. During the installation of a new steel bottom over an existing steel bottom, which has been repaired, if water or other electrolyte intrudes into the annulus, what can happen? a) A galvanic cell may form which will cause the new steel tank bottom to corrode at an accelerated rate b) An electrochemical reaction may take place creating hazardous gasses c) A galvanic cell may form which will cause the old tank bottom to corrode at an accelerated rate d) A galvanic cell may form which will turn the old tank bottom into an anode Reference: API RP 651, Paragraph 5.4.3.2 ANS: A Q30. With the installation of _____ in a diked area prior to new tank construction, most cathodic protection systems are rendered ineffective. a) A secondary containment system utilizing a perforated impervious membrane b) A secondary containment system utilizing an impervious membrane c) A secondary containment system utilizing a metallic impregnated screen membrane d) A secondary containment system utilizing a non-impervious membrane Reference: API RP 651, Paragraph 5.4.3.3 ANS: B
Charlie Chong/ Fion Zhang
Answers to API-651 Section 5, Determination of Need for Cathodic Protection
Charlie Chong/ Fion Zhang
Section 6- Methods of Cathodic Protection for Corrosion Control Q1. What is the basic principle that makes cathodic protection effective. a) Cathodic protection is a technique for preventing corrosion by making the entire surface of the metal to be protected act as the rectifier b) Cathodic protection is a technique for preventing corrosion by making the entire surface of the metal to be protected act as the corrosion cell c) Cathodic protection is a technique for preventing corrosion by making the entire surface of the metal to be protected act as the cathode d) Cathodic protection is a technique for preventing corrosion by making the entire surface of the metal to be protected act as the anode Reference: API-651, Paragraph 6.1 ANS: C
Charlie Chong/ Fion Zhang
Q2. What are the two systems of cathodic protection? a) Galvanic and repressed current b) Galvanic and impressed current c) Galvanic and reversed current d) Galvanic and induced current Reference: API-651, Paragraph 6.1 ANS: B Q3. Galvanic cathodic protection systems use a metal, that is more active than the structure to be protected, to supply the current required to stop corrosion. What is another term(s) used to describe this material? a) Anode, commonly referred to as a galvanic or sacrificial anode b) Cathode, commonly referred to as a galvanic or sacrificial cathode c) Ribbon cathode, commonly referred to as a sacrificial ribbon cathode d) Impressed current anode, commonly referred to as the impressed anode Reference: API-651, Paragraph 6.2.1 ANS: A
Charlie Chong/ Fion Zhang
Q4. Where on the galvanic series is clean and shiny mild steel? a) Clean and shiny mild steel has a value of –1.1 volts b) Clean and shiny mild steel has a value of –1.0 volts c) Clean and shiny mild steel has a value of –0.8 volts d) Clean and shiny mild steel has a value of –0.5 to -0.8 volts (v.s CSE) Reference: API-651, Paragraph 6.2.1 and Table 3 ANS:D Q5. The most common metals used as galvanic anodes in soil are: a) Lead and copper b) Aluminum alloy (5% zinc) and Mild steel (clean and shiny) c) Magnesium and zinc d) Mild steel in concrete and cast iron Reference: API-651, Paragraph 6.2.1 ANS: C
Charlie Chong/ Fion Zhang
Q6. Of the following, which is not an advantage of galvanic cathodic protection systems? a) No external power is needed b) Capital investment is low for small-diameter tanks c) Method is limited to use in low-resistivity soils d) Interference problems (stray currents) are rare Reference: API-651, Paragraph 6.2.2 ANS: C Q7. Impressed current cathodic protection systems use: a) Alternating current b) Direct current usually provided by a rectifier c) Direct current usually provided by a dry cell battery d) Either direct current or alternating current depending upon which is available Reference: API-651, Paragraph 6.3.1 ANS: B
Charlie Chong/ Fion Zhang
Q8. Of the following, which is not a disadvantage of impressed current cathodic protection systems? a) High current output b) High maintenance costs c) High operating costs d) High capital cost for small installations Reference: API-651, Paragraph 6.3.3 ANS: A Q9. A cathodic protection rectifier has two major components; what are they? a) A step-down transformer to reduce the AC supply voltage and rectifying elements to convert DC to AC output b) A step-down transformer to reduce the AC supply voltage and rectifying elements to convert AC to DC output c) A step-down transformer to reduce the DC supply voltage and rectifying elements to convert DC to AC output d) A step-down transformer to reduce the AC supply voltage and rectifying elements to regulate the AC output Reference: API-651, Paragraph 6.3.3 ANS: B
Charlie Chong/ Fion Zhang
Q10. Impressed current anodes used in soil are not made of: a) Graphite b) High silicon cast iron c) Zinc d) Mixed metal oxides on titanium Reference: API-651, Paragraph 6.3.5 ANS: C Q11. Impressed current anodes may be installed underneath the tank. a) True b) False Reference: API-651, Paragraph 6.3.5 ANS: A
Charlie Chong/ Fion Zhang
Answers to API-651 Section 6, Methods of Cathodic Protection for Corrosion Control
Charlie Chong/ Fion Zhang
Section 8 â&#x20AC;&#x201C; Criteria for Cathodic Protection Q1. API-651 provides criteria for determining the adequacy of cathodic protection of aboveground storage tanks. What document is referenced for a more detailed description? a) ASME Section V, Nondestructive Examination b) API-Standard 650, Welded Steel Tanks for Oil Storage c) API-Standard 653, Tank Inspection, Repair, Alteration, and Reconstruction d) NACE RP-01-69 Reference: API-651, Paragraph 8.2.1 ANS: D 8.2 Protection Criteria 8.2.1 There are several criteria used to determine if adequate cathodic protection has been achieved on aboveground storage tanks. For a more detailed description, refer to the latest edition of NACE RP0193.
Charlie Chong/ Fion Zhang
NACE RP0193-2001 Standard Recommended Practice - External Cathodic Protection of On-Grade Metallic Storage Tank Bottoms. NACE RP0169-2002 Control of External Corrosion on Underground or Submerged Metallic Piping Systems.
Charlie Chong/ Fion Zhang
Q2. In determining if adequate cathodic protection is being achieved, which of the following would be correct? a) A negative (cathodic) potential of at least 850 mV with cathodic current applied b) A positive (cathodic) potential of at least 850 mV with cathodic current applied c) A negative (cathodic) potential of at least 85.0 mV with cathodic current applied d) A positive (cathodic) potential of at least 85.0 mV with cathodic current applied Reference: API-651, Paragraph 8.2.2.1 ANS: A
Charlie Chong/ Fion Zhang
Q3. How must the required negative potential be measured? a) This potential shall be measured with respect to a saturated copper/copper sulfate reference electrode (CSE) contacting the metal tank bottom b) This potential shall be measured with respect to a saturated copper/copper sulfate reference electrode (CSE) contacting the electrolyte c) This potential shall be measured with respect to a saturated copper/copper sulfate reference electrode (CSE) contacting the metal casing of the rectifier d) This potential shall be measured with respect to a saturated copper/copper sulfate reference electrode (CSE) contacting the positive terminal of the power source Reference: API-651, Paragraph 8.2.2.1 ANS: B
Charlie Chong/ Fion Zhang
Q4. In determining if adequate cathodic protection is being achieved, which of the following would be correct? a) Negative polarized potential of at least 8.50 mV relative to a CSE b) Negative polarized potential of at least 85.0 mV relative to a CSE c) Negative polarized potential of at least 850 mV relative to a CSE d) Negative polarized potential of at least .850 mV relative to a CSE Reference: API-651, Paragraph 8.2.2.2 ANS: C Q5. Name a common method of measuring polarized potential. a) Measuring the distance between the tank bottom and the anode b) Measuring the AC current relative to the DC current c) Using the “instant on” method d) Using the “instant off” method Reference: API-651, Paragraph 8.2.2.2 ANS: D
Charlie Chong/ Fion Zhang
Q6. In determining if adequate cathodic protection is being achieved, which of the following would be correct? a) A minimum of 1000 mV of cathodic polarization measured between the tank bottom metallic surface and a standard reference electrode contacting the electrolyte b) A minimum of 850 mV of cathodic polarization measured between the tank bottom metallic surface and a standard reference electrode contacting the electrolyte c) A minimum of 100 mV of cathodic polarization measured between the tank bottom metallic surface and a standard reference electrode contacting the electrolyte d) A minimum of -0.85 mV of cathodic polarization measured between the tank bottom metallic surface and a standard reference electrode contacting the electrolyte Reference: API-651, Paragraph 8.2.2.3 ANS: C
Charlie Chong/ Fion Zhang
Q7. The standard method of determining the effectiveness of cathodic protection on a tank bottom is the __________ measurement a) Resistivity b) DC current c) Tank-to-soil d) Interference current Reference: API-651, Paragraph 8.3.1 ANS: C
Charlie Chong/ Fion Zhang
Q8. How is the tank-to-soil potential measurement performed? a) This measurement is performed using a low-impedance voltmeter and a stable, reproducible reference electrode contacting the electrolyte b) This measurement is performed using a high-impedance voltmeter and a stable, regenerative reference electrode contacting the electrolyte c) This measurement is performed using a high-impedance voltmeter and a stable, reproducible reference electrode contacting the electrolyte d) This measurement is performed using a high-impedance voltmeter and an unstable, non-reproducible reference electrode contacting the electrolyte Reference: API-651, Paragraph 8.3.1 ANS: C
Charlie Chong/ Fion Zhang
Q9. Tank-to-soil potential measurements are typically taken with current applied; however, corrections for ______ in the soil must be made. a) IW drop(s) b) IR drop(s) c) ER drop(s) d) IE drop(s) Reference: API-651, Paragraph 8.3.2 ANS: B Q10. Correction for IR drop in the soil is often necessary for measurements made at the tank perimeter even if the reference electrode is placed immediately adjacent to the tank. This is especially true if ______ is/are close to the tank. a) Distributed anodes b) The cathodic protection power supply rectifier c) The sacrificial anode d) The DC power supply (battery) Reference: API-651, Paragraph 8.3.2 ANS: A
Charlie Chong/ Fion Zhang
Q11. Monitoring the actual structure-to-soil potential under the tank should be considered. How can this be accomplished? a) Permanently installed reference electrode or by burying reference electrode every 20 feet around the perimeter of the tank b) Inserting a reference electrode under the tank through a perforated tube or attaching a reference electrode to the tank shell c) Permanently installed reference electrode or by inserting a reference electrode under the tank through a perforated tube d) Permanently installed bare copper wire connected to the tank bottom or by inserting a reference electrode under the tank through a perforated tube Reference: API-651, Paragraph 8.3.4 ANS: C
Charlie Chong/ Fion Zhang
Q12. Other standard reference electrodes may be substituted for the saturated copper/copper sulfate reference electrode. Which of the following is not a common substitute? a) Reference electrode ➪ Zinc, Voltage ➪ +0.25 b) Reference electrode ➪ Saturated KCI calomel Voltage ➪ -0.78 c) Reference electrode ➪ Silver/silver chloride Voltage ➪ -0.80 d) Reference electrode ➪ Aluminum alloy (5% zinc) Voltage ➪ +0.08 Reference: API-651, Paragraph 8.4 and Table 4 ANS: D
Charlie Chong/ Fion Zhang
Answers to API-651 Section 8, Criteria for Cathodic Protection
Charlie Chong/ Fion Zhang
Section 11 â&#x20AC;&#x201C; Operation and Maintenance of Cathodic Protection Systems Q1. Why is it important to conduct potential surveys when there is an adequate liquid level in a tank? a) Bottom-to-electrolyte potential readings may indicate adequate protection for the portion of the tank in contact with the soil but when the tank is full and all of the bottom is in contact, protection may not be sufficient b) Bottom-to- anode potential readings may indicate adequate protection for the portion of the tank in contact with the soil but when the tank is full and all of the bottom is in contact, protection may not be sufficient c) Bottom-to-cathode potential readings may indicate adequate protection for the portion of the tank in contact with the soil but when the tank is full and all of the bottom is in contact, protection may not be sufficient d) Bottom-to-electrolyte potential readings may indicate adequate protection for the portion of the tank in contact with the soil but when the tank is full and all of the bottom is in contact, protection may be far more than necessary Reference: API-651, Paragraph 11.1.3 ANS: A
Charlie Chong/ Fion Zhang
Q2. Measurements of the native structure-to-soil potential should be made ___. a) Immediately after any cathodic protection system is energized (?) b) Within two days after any cathodic protection system is energized c) Within 6 months after any cathodic protection system is energized d) Prior to energizing a new cathodic protection system Reference: API-651, Paragraph 11.3.1 ANS: D Q3. After a system has been energized, it may take _____ for polarization to a steady state to take place. a) Two and a half years b) One year c) Several months d) Fifteen minutes Reference: API-651, Paragraph 11.3.1 ANS: C
Charlie Chong/ Fion Zhang
API651: 11.3 Cathodic Protection Surveys 11.3.1 General 11.3.1.1 Prior to energizing a new cathodic protection system, measurements of the native structure-to-soil potential should be made. Immediately after any cathodic protection system is energized or repaired, a survey should be conducted to determine that it operates properly. An initial survey to verify that it satisfies applicable criteria should be conducted after adequate polarization has occurred. (?) Polarization to a steady state may take several months after the system is energized. Keywords: â&#x2013; after adequate polarization has occurred. â&#x2013; Immediately after any cathodic protection system is energized or repaired,
Charlie Chong/ Fion Zhang
Q4. To ensure the effectiveness of cathodic protection, how often should cathodic protection surveys be taken? a) Every two years b) Annually c) Bi-annually d) Quarterly Reference: API-651, Paragraph 11.3.2 ANS: B Q5. How often should all sources of impressed current be checked? a) At intervals not exceeding two years b) At intervals not exceeding one year c) At intervals not exceeding two months d) At intervals not exceeding two weeks Reference: API-651, Paragraph 11.3.3.1ANS: C
Charlie Chong/ Fion Zhang
11.3.2 Inspection, Testing, and Maintenance of Cathodic Protection Facilities 11.3.2.1 Inspection and tests of cathodic protection facilities should be made to ensure their proper operation and maintenance. 11.3.2.2 All sources of impressed current should be checked at intervals not exceeding two months unless specified otherwise by regulation. Evidence of proper function may be current output, normal power consumption, a signal indicating normal operation, or satisfactory electrical state of the protected structure. A satisfactory comparison between the rectifier operation on a bimonthly basis and the rectifier operation during the annual survey implies the protected status of affected structures is similar. This does not take into account possible effects of foreign current sources.
Charlie Chong/ Fion Zhang
Q6. Tank bottoms shall be examined for evidence of corrosion at least once each year by conducting an internal inspection and taking coupon cutouts. a) True b) False Reference: API-651, Paragraph 11.3.3.4 ANS: B Q7. Records to demonstrate the need for corrosion control measures should be retained for a) 5 years b) 10 years c) 15 years d) As long as the facility remains in service Reference: API-651, Paragraph 11.4.7 ANS: D
Charlie Chong/ Fion Zhang
Q8. Records related to the effectiveness of cathodic protection should be retained for a ______ period unless a shorter period is specifically permitted by regulation a) 5 years b) 10 years c) 15 years d) As long as the facility remains in service Reference: API-651, Paragraph 11.4.7 ANS: A API651:11.4.7 ď Ž Records sufficient to demonstrate the need for corrosion control measures should be retained as long as the facility involved remains in service. ď Ž Records related to the effectiveness of cathodic protection should be retained for a period of five years unless a shorter period is specifically allowed by regulation.
Charlie Chong/ Fion Zhang
API651:11.4.7 ď Ž Records sufficient to demonstrate the need for corrosion control measures should be retained as long as the facility involved remains in service. ď Ž Records related to the effectiveness of cathodic protection should be retained for a period of five years unless a shorter period is specifically allowed by regulation.
Charlie Chong/ Fion Zhang
Answers to API-651 Section 11, Operation and Maintenance of Cathodic Protection Systems
Charlie Chong/ Fion Zhang
Charlie Chong/ Fion Zhang
ANS: ANS:
Charlie Chong/ Fion Zhang
ANS: ANS:
Charlie Chong/ Fion Zhang
Charlie Chong/ Fion Zhang
Charlie Chong/ Fion Zhang
Good Luck!
Charlie Chong/ Fion Zhang
Good Luck!
Charlie Chong/ Fion Zhang