Understanding APIICP653 Readi Re ading ng 8 Works Workshee heet-0 t-05 5 Part Part 2a of 2 My Pre-exam Self Study Notes 26 th February 2015
AST Tanks
API 653 Exam Administration 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
API 653 Exam Administration 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
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
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 f or Oil Storage, Twelfth Edition, March 2013 with Addend Addendum um 1 (September (September 2014), 2014), Errata 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.
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Americ Amer ican an Soci Society ety of Mec Mechan hanica icall Engi Enginee neers rs (ASM (ASME) E),, Boil Boiler er and and Pre Pressu ssure re Vessel Code, 2013 Edition i. ASME AS ME Se Sect ctio ion n V, V, Non Nonde dest stru ruct ctiv ivee Exa Exami mina nati tion on,, Arti Articl cles es 1, 2, 6, 7 and and 23 (section SE-797 only) ii.. Se ii Sect ctio ion n IX, IX, We Weld ldin ing g and and Br Braz azin ing g Qua Quali lifi fica cati tion onss (We (Weld ldin ing g Onl Only) y)
See end of this study note for API Official BOK
http://independent.academia.edu/CharlieChong1 http://www.yumpu.com/zh/browse/user/charliechong http://issuu.com/charlieccchong
The Magical Book of Tank Inspection ICP
Fion Zhang at Xitang 26th February 2016
Subject API Standard 650
API650 Welded Tanks Tanks for Oil Storage API API STANDARD STANDARD 650 TWELFTH EDITION, MARCH 2013
API650 Section 1 Scope
Q1. API 650 covers the design, materials, fabrication, erection, and testing of aboveground steel storage tanks. What is the t he 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 pressure shall not exceed the weight of the roof plates d) Maximum pressure pressure shall not exceed the weight of the floor plates ANS: c Q2. API-650 applies only to tanks whose entire bottom is uniformly supported and tanks in ___ that have a maximum operating temperature 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 ANS: b
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 ANS: a 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 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 ANS: c
Others F.1.3 Internal pressures that exceed the nominal weight of the shell, roof, and framing fram ing but do not exceed exceed 18 kPa (21/2 lbf/in.2) lbf/in.2) gauge gauge when the shell shell is anchored to a counterbalancing weight, such as a concrete ringwall, are covered in F.2 and F.7.
An A n s w ers er s t o A PI-Stan PI-St and d ard ar d 650 Sect Sec t i o n 1, Sco Sc o p e
API650 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 t he manufacturer accepts 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 as meeting all the requirements requirements of a material listed in API-650 and is approved by the purchaser ANS: d
Q2. If a new or unused plate plate cannot be completely identified, 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 t he material passes the tests prescribed in ASME Section VIII, Div. 2 ANS: b Q3. What is the maximum 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
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 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 tempered ANS: a
Q6. What is the maximum shell plate thickness permitted for a tank fabricated of ASTM A 36 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 ANS: d Q7. What is the maximum shell plate thickness permitted for a tank fabricated of ASTM A 285, 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 ANS: a
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 ANS: c Q9. When conducting conducting impact impact tests, how many many specimens specimens are required 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 tests shall be performed on two specimens specimens taken from a single test coupon c) Impact Impact tests shall shall be performed 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 ANS: c
Q10. In situations where it is not possible to obtain full size specimens, what is the required required width width along the notch notch for subsize subsize specimen specimens? s? a) 60% of the t he material thickness b) 80% of the t he material thickness c) 90% of the t he material thickness d) 75% of the t he material thickness ANS: b Q11. Unless data is available available to justify a different different temperature, temperature, what must must the design metal temperature be for an aboveground storage tank to be installed in Birmingham, Alabama? (0°F) a) The design temperature shall be assumed to be 25°F b) The design temperature shall be assumed to be 15°F c) The design temperature shall be assumed to be 20°F d) The design temperature shall be assumed to be 10°F ANS: b
Q12. Unless data is available available to justify a different different temperature, temperature, what must must the design metal temperature be for an aboveground storage tank to be installed in Indianapolis, Indiana? (-15°F) 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 ANS: c Q13. What is the required average longitudinal impact value of three specimens taken from a 1.375 inch thick th ick 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 ANS: c
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India ndi anapolis: napoli s: -10 F or -15 -15 F? — Design Metal Metal Temperature*: Temperature*: Enter either lowest 1-day mean mean temperature temperature plus 8°C (15°F) or a lower temperature as specified by the Purchaser if operating conditions and/or local atmospheric atmospheric conditions control fracture toughness issues.
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 ANS: d
Q15. Longitudinal impact tests are performed on three specimens, taken from a 1.5 inch thick A 516M-70(485) 516M-70(485) as rolled test coupon with the following results: Specimen Specimen #1 – 42 foot-poun foot-pounds, ds, Specimen Specimen #2 – 18 foot-poun foot-pounds, ds, Specimen Specimen # 3 – 31 foot-po foot-pounds unds.. 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 ANS: d
An A n s w ers er s t o A PI-Stan PI-St and d ard ar d 650 Sect Sec t i o n 2, Mater Mat erii als al s
API650 Section 3 Designs
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 ANS: c Q2. What What is the minimu minimum m size size fillet fillet weld weld permitt permitted ed when when joining joining a 1” thick plate plate to a ¾” thick thick plat plate? e? a) 3/16” b) 1/4” c) 3/8” d) 1/2” ANS: b 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
Q3. For lap-welded joints that are tack welded, what is the minimum amount of lap permitted? a) The lap need not exceed 2” (double lapped) b) The lap need not exceed 1” (single lapped) c) The joint shall be lapped at least 5 times the minimum required required thickness of the thinner plate d) The joint shall be lapped at least 5 times the nominal thickness of the thinner plate 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 ANS: a
Q5. Vertical shell shell joints may may be partial partial penetration groove welds welds welded from both sides. a) True b) False 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” 1.25” thick and the secon second d course course which is 1” thick? 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 ANS: d
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 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 ANS: c
Q9. What is the minimum minimum size size fillet weld require required d on each side of the shell shell plate attaching shell plate to the annular annular plate? The The shell plate plate is 1.25” thick. a) 3/8 inch b) 3/16 inch c) 1/4 inch d) 5/16 inch ANS: 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 ANS: c
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 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 ANS: b
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 ANS: πD = 4 (round up) D Q14. The purchaser orders an an aboveground aboveground storage tank and insists on a corrosion allowance in the bottom plates of .125 inches. What What is the minimum 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 ANS: 0.236+ 0.125 = 0.361 0.361 used C
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 (2”) d) Minimum projection is 10.0 inch ANS: c 5.4.2 Bottom plates of sufficient size shall be ordered so that, when trimmed, at least least a 50 mm (2 in.) in.) width will will project project outside outside the shell shell or meet requirements requiremen ts given in 5.1.5.7 d whichever is greater. Q16. Annular bottom plates shall have a radial width that provides at least ____ between the inside inside of the shell and any lap-welded joint joint in the remainder of the bottom. a) 12 inches b) 24 inches c) 1.2 inches d) 2.4 inches ANS: b
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 ANS: c 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 ANS: c
Table 5.1b— 5.1b—An Annu nular lar Bott Bo ttom om--Plate Plate Thi Thick cknesses nesses (t b ) (USC)
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 ANS: b 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 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 ANS: d Q22. In calculating calculating the net plate thickness for an AST fabricated of A 516M 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 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 ANS: c 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 ANS: d
Q25. Openings in tank shells, larger than that required to accommodate a ____ flanged or threaded threaded nozzle shall be reinforced. reinforced. a) 2 inch b) 2.5 inch c) 3 inch d) 3.5 inch ANS: a 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 t he 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 t he weld size ANS: c
5.7.3.1 For non-stress-relieved 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 mm (10 in.) in.) from the centerline 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.
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 ANS: c 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-to-bottom weld. a) Ten inches b) Eight inches c) Six inches d) Three inches ANS: a
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 ANS: b
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 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 ANS: c
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 ANS: b Q33. What is the bolt circle diameter for a cover plate plate used with a 30 inch diameter manhole? a) 32 ¾ inch inch b) 36 ¼ inch inch c) 38 ¾ inc inch d) 42 ¼ inch inch ANS: b
Table 5.3 5.3b—T b—Thi hick ckness ness of o f Shell Manh Manhol ole e Cover Plate Plate and and Bolt Bo ltin ing g Flange (USC)
Q34. The purchaser has ordered a 36 inch manhole to be installed in i n 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 ANS: c Q35. API 650 requires telltale holes in reinforcing plates. What is the required dimension of this hole and what should be done done with it after the initial re-pad pressure test? a) The hole hole shall be 3/8 3/8 inch diamete diameterr and shall shall be left open 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 inch diameter and shall be closed after testing d) The hole shall be be 1/4 inch diameter and and shall be be closed after testing
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 opening is not more more than ¼ the height or diameter of the opening closer closer to the center of the the cover plate 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 ANS: a Q38. An aboveground aboveground storage tank has a design 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 ANS: c
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 of the opening opening is 24.625” 24.625” and the OD of the reinforcing reinforcing plate is 42” b) The diameter of the opening opening is 24.625” 24.625” and the OD of the reinforcing reinforcing plate is 46” c) The diameter of the opening opening is 24.750” 24.750” and the OD of the reinforcing reinforcing plate is 42” d) The diameter of the opening opening is 24.750” 24.750” and the OD of the reinforcing reinforcing plate is 46” ANS: b
Q40. What is the minimum thickness permitted 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 ANS: D 5.8.6.2 The cover plate thickness and/or structural support shall be designed to limit maximum fiber stresses in accordance with this standard, however, cover plate thickness shall not not be less than 5 mm (3/16 (3/16 in.). In addition to other expected design loads, consider a 112 kg (250 lb) person standing in the center of the installed/closed cover. The designer shall consider wind in the design of hinged openings and how removed covers will be handled without damage (adequate rigidity).
Q41. Stiffening ring 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 ANS: d 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 be not less than 3 feet 6 inches clear of the projecting curb angle on the top of the t he 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 be not less than 2 feet 4 inches clear of the projecting curb angle on the top of the t he tank shell ANS: d
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 ANS: a 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 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 (7-gauge?) ANS: d 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 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 compensation d) A frangible roof ANS: d
API650: A PI650: 5.10.2.2 Roo Ro o f Plat Pl ate e Thi Th i c k n ess es s : Roof plates shall have a nominal thickness of of not less than than 5 mm (3/16 in.) or or 7- gauge sheet. Increased thickness may be required for supported cone roofs (see 5.10.4.4). Any required corrosion allowance allowance for the plates plat es of self-supporting roofs shall be added to the calculated thickness unless otherwise specified by the Purchaser. Any corrosion allowance for the plates of supported roofs shall be added to the greater of the calculated thickness or the minimum thickness or [5 mm (3/16 in.) or 7-gauge sheet]. For frangible roof tanks, where a corrosion allowance is specified, the design must have frangible characteristics in the nominal (uncorroded) condition. API650: A PI650: C.3.3.2 Unless otherwise specified by the Purchaser, all deck plates shall have a minimum nominal thickness of 4.8 mm (3/16 in.) (permissible ordering basis—37.4 kg/m2, 7.65 lbf/ft2 of plate, 0.180-in. plate, or 7-gauge sheet).
API653: A PI653: 9.11.2 Sup Su p p o r t ed Con Co n e Roo Ro o f s 9.11.2.1 The minimum thickness of new roof plates shall be 3/16 in. plus any corrosion allowance as specified in the repair specifications. In the event roof live loads in excess of 25 lbf/ft2 are specified (such as insulation, operating vacuum, high snow loads), the plate thickness shall be based on analysis using the allowable stresses in conformance with API 650, Section 5.10.3 (see 9.11.2.2). 9.11.2.2 The roof supports (rafters, girders, columns, and bases) shall be repaired or altered such that under design conditions the resulting stresses do not exceed the stress levels given in API 650, Section 5.10.3.
Q47. Rafters shall be spaced so that in the outer ring, their centers are not more than _____ apart measured along the circumference 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 ANS: b
An A n s w ers er s t o A PI-Stan PI-St and d ard ar d 650 Sect Sec t i o n 3, Desi Des i g n
Roasted Duck 烤鸭
Roasted Duck 烤鸭
Roasted Duck 烤鸭
Stewed Duck 卤鸭