Api 650 & 653 questions closed book with answers

1. API 650 & 653
PRACTICE QUESTIONS (CLOSED BOOK)
1. Pick the correct manual welding rod that must be used to make Hot Taps or for
reconstruction of above ground storage Tanks.
E7018
2. The new nameplate for a reconstructed API 653 tank shall be placed:
Adjacent to existing nameplate.
3. Radiographs for reconstructed tanks shall be:
Retained for at least 1 year.
4. It is not necessary to consider the possibility of brittle fracture of a tank if the
following exists. The tank shell thickness is:
Less than/equal (</=) ½”, the tank operates over 60F or the membrane stress of
the tank is below 7000psi.
5. The following welds do not need a welder identification.
Roof plate welds and flange-to-nozzle neck welds.
6. Roof plates of an aboveground storage tank shall be repaired or replaced if the
average thickness of the plates have corroded to:
Less than 0.09” in any 100 square inch area.
7. If the requirements of a jurisdiction are more stringent than the requirements of API
653, then the requirements of:
The jurisdiction shall govern.
8. Aboveground storage tanks are primarily inspected to:
Ensure the safety and integrity of the tanks.
9. Atmospheric storage tanks are defined as tanks that are designed to withstand an
internal pressure:
Up to but not exceeding 2.5 psi gauge.
10. Three types of external inspections of above ground tanks are:
Routine in-service inspections, formal visual external inspection, and in-service
UT thickness measurements of the shell.
11. When corrosion rates are not known, tank bottom actual thickness shall be
determined by inspection within the next ______ years of tank operation to establish
corrosion rates.
10
12. A 48’ high by 100’ diameter aboveground storage tank is checked for out-of-
plumbness. The permissible out-of-plumbness was found to be:
5”
13. A hot tap is installed on an aboveground storage tank. A reinforcing plate has been
welded to the shell and pneumatically tested per API 650. After the valve has been
installed on the hot tap nozzle, a pressure test is performed on the nozzle prior to
mounting the hot tap machine. What pressure is used?
1.5 times the hydrostatic head.
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2. API 650 & 653
PRACTICE QUESTIONS (CLOSED BOOK)
14. A new tank is placed in service. In seven (7) years the following inspections should
have been made:
Routine visual, formal visual (external), and UT inspections.
15. API 653 specifies what temperature for preheat on plate thickness over 1.5”?
200F
16. Routine visual in-service inspections of aboveground storage tanks from the ground
may be done by:
Owner / user personnel other than authorized inspectors.
17. A formal visual external inspection by an authorized aboveground storage tank
inspector shall be made at least every _____ years or at RCA/4N years, whichever is
less.
5
18. External, UT measurements of a new tank shell shall be made not later than _____
years after commissioning.
5
19. In no case shall the internal inspection interval of an aboveground storage tank
exceed _____ years.
20
20. A tank built new in January, 1988 was removed from service and internally inspected
January, 1998. The bottom course of the tank showed the most general corrosion (no
isolated corrosion was found). The original thickness of the bottom course of the tank
was 1”. The measured thickness of the bottom course at the inspection was 0.93”.
Determine the corrosion rate.
0.0070”/year
21. When a fully hydrostatic test is required, it shall be held for ____ hours.
24
22. A full hydrostatic test is always required on:
A reconstructed tank.
23. The maximum acceptable undercutting on horizontal butt welds of a reconstructed
tank is _____ inch.
1/32
24. The minimum number of settlement points around a tank periphery is:
8
25. The maximum spacing of settlement points is _____ feet around the circumference.
32
26. Which of the following is not considered shell distortion?
Uniform settlement of a tank.
27. If any provision of API 653 presents a direct or implied conflict with any statutory
regulation and the statutory regulation is more stringent:
The government regulations govern.
28. If a contractor is to relocate or reconstruct an aboveground storage tank, the limits of
responsibilities are defined by:
The owner / operator.
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3. API 650 & 653
PRACTICE QUESTIONS (CLOSED BOOK)
29. If a weld is made on a tank shell plate that is thicker than 1 inch, the base metal
within 3 inches of the welding shall be heated to a temperature of approximately:
140F
30. Widely scattered pits may be ignored provided _______ and the sum of their
dimensions along any vertical line does not exceed 2” in an 8” length.
No pit depth is greater than ½ tmin exclusive of the corrosion allowance.
31. The critical zone is that portion of the bottom or annular plate with in:
3” of the inside edge of the shell measured radially inward.
32. The following repairs are allowed within the critical zone of repair of a tank bottom:
Welding of widely scattered pits, pinholes, and cracks in the bottom plate.
33. In addition to API 650 requirements, API 653 requires that _____ radiograph(s) is/are
required for a repaired vertical weld joint.
One
34. When a weld fails RT, how many additional radiographs are required?
Two spots adjacent to the unacceptable weld section shall be RT’d.
35. With a horizontal sweep board 36” long, peaking shall not exceed _____ inch.
0.500”
36. A 48’ high tank has a diameter of 127’. What is the max out-of-plumbness allowed?
5.0”
37. What is the main factor in determining the efficiency of a rivet joint in a tank?
The number of rivet rows.
38. A new 100’ diameter tank must have at least _____ inches thick shell plates.
¼”
39. Welders are qualified to what standard or code?
Section IX of ASME Code
40. Radiographs of repaired work and records of radiographs of repaired work shall be
marked with:
The letter “R”.
41. All leaks in pontoons or compartments of double deck floating roofs shall be repaired
by:
Rewelding the leaking joints and/or the use of patch plates.
42. Acceptance criteria for a radiograph of a repaired on a tank is found:
Section VIII of the ASME Code.
43. API Standard 653 requires new welds of shell to bottom plate to be inspected:
Their entire length by right-angle vacuum box and solution film or by applying
light diesel oil.
44. An internal inspection interval for above ground storage tanks must not be greater
than:
20 years.
45. UT measurements are required on a tank shell, how many measurements shall be
taken:
Owner / operator judgment.
46. Non homogeneous fill, such as a lump of clay in the sand of a foundation pad under
the tank bottom is one factor that:
Can cause corrosion and tank bottom leakage.
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4. API 650 & 653
PRACTICE QUESTIONS (CLOSED BOOK)
47. RT procedures to satisfy the requirements of API 653 should be evaluated in
accordance with:
ASME Code, Section V.
48. Newly welded bottom joints shall be tested using a vacuum box and solution film or
by means of:
Tracer gas and detector examination.
49. A tank has a shell corrosion rate of 5 mils per year and a remaining corrosion
allowance of 0.17”. For this tank, the maximum interval for service UT thickness
measurements is:
15 years.
50. Formal in service visual external inspection must be conducted by:
An inspector qualified in accordance with API 653.
51. UT testing inspection of the shell plate for laminations in the affected area is
mandatory when:
A reinforcement plate is added to an existing un-reinforced shell penetration.
52. Which type of repair of a crack is allowed in the tank shell to tank bottom weld?
Remove the entire crack and repair the weld.
53. When external ultrasonic thickness measurements are used to determine a rate of
general uniform corrosion relevant to the integrity of new tank shell and the rate of
corrosion is not known, what is the maximum interval for ultrasonic thickness
measurements?
5 years.
54. When preparing a tank prior to installing a replacement bottom over an existing
bottom, the tank shell must be separated from the tank bottom by cutting the shell
parallel to the tank bottom a minimum of __________ above the bottom-to-shell weld
or by removing the entire shell-to-bottom weld and the HAZ by gouging or grinding.
½”
55. Distortion of anchor bolts and excessive cracking of the concrete structures in which
the anchor bolts are embedded may be indications of:
Over pressure up lift condition.
56. Guidance for evaluation of an existing external floating roof shall be based on criteria
in:
API 650 appendix C.
57. The recommended procedure for accessing the risk of failure due to brittle fracture is
based on:
A decision tree analysis and appropriate factors.
58. Penetrations installed using insert plates shall have the butt-weld examined by means
of:
Full radiograph.
59. Certification that the tank has been reconstructed in accordance with API 653 is
normally done by:
Reconstruction organization.
60. All the following must be included in a general inspection report except:
Operating history of the tank.
61. Who has the ultimate responsibility for complying with the provisions of API 653?
Owner / Operator.
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5. API 650 & 653
PRACTICE QUESTIONS (CLOSED BOOK)
62. Radiographs taken of a reconstructed tank shall be retained:
One year.
63. For tanks to be reconstructed, all shell plate materials and bottom plates welded to the
shell shall be identified. Material not identified shall be:
Tested and identified by chemical analysis and mechanical test as required by
ASTM A-6 and A370 including Charpy V-notch test.
64. During hydrostatic tests of repaired or reconstructed tanks foundation settlement shall
be measured during filling and when water reaches what percentage of the test level?
100%
65. With regard to a full hydrostatic test of a tank, the correct statement below is that this
test:
Is always required for major repairs/alterations unless special requirements of
API 653 are followed.
66. The maximum vertical and horizontal dimension of a lapped patch repair plate is
____ & ____ inches respectively.
48” & 72”
67. Completed welds of stress relieved assemblies of shell penetrations shall be examined
by visual and MT or PT methods:
After stress relief and before the hydrostatic test.
68. If it necessary to replace a roof rim, the new roof rim shall be a minimum thickness
of:
3/16”
69. Rim-mounted primary shoe seals and toroidal seal systems can be removed, repaired,
or replaced. To minimize evaporation losses and reduce potential hazards to workers,
no more than:
1/4 of the roof seal system should be out of an in-service tank at one time.
70. Welding procedure specification (WPS), and welders and welding operators shall be
qualified in accordance with:
Section IX of the ASME Code.
71. When a tank is reconstructed, each welder and welding operator shall be assigned:
An identifying number, letter, or symbol.
72. When a tank is reconstructed, in lieu of other means of identification, the welder or
welding operator’s identification mark shall be hand or machine stamped adjacent to
and at intervals along the completed weld not exceeding:
3’ along completed welds.
73. Acceptable settlement may be determined as described in Appendix B of API
Standard 653. An alternate to this is:
A rigorous stress analysis of the tank may be carried out.
74. The minimum dimension of a lapped patch repair plate is:
6”
75. The thickness to be used for each shell course when checking the design for a
reconstructed and relocated tank shall be based on measurements taken within _____
days prior to relocation.
180
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6. API 650 & 653
PRACTICE QUESTIONS (CLOSED BOOK)
76. The projection of the bottom plate beyond the outside toe of the shell-to-bottom weld
shall be at least ____ inch.
0.3750
77. In lieu of stamping complete welds:
A record may be kept that identifies the welder or welding operator employed for
each welded joint.
78. If a tank shell has a thickness no greater than _____ the risk of failure due to brittle
fracture is minimal, provided that an evaluation for suitability of service per section 2
of API 653 has been performed.
0.500”
79. Where concrete ringwalls are provided under the shell, the top of the ringwall shall be
level within ____ in any 30’ of the circumference measured from the average
elevation.
Plus or minus 1/8”.
80. When design and construction details are not given and are not available for a tank,
then details that will provide a level of integrity equal to the level provided by the
current edition of _______ must be used.
API Standard 650
81. Excess settlement during a hydrotest shall be cause to:
Stop the test for foundation investigation and / or repair.
82. Impact testing is not required for a design temperature of:
Greater than 60F.
83. Where concrete ring walls are provided under the shell, the top of the ringwall shall
be level within +/- _____ inch in any 30’ of circumference and +/- _____ inch in the
total circumference measured from the average elevation.
1/8” and ¼”
84. The measurement for internal bottom settlement shall have maximum of _____ feet
spacing between elevation points across the diameter?
10
85. Completed welds of stress relieved assemblies shall be examined by _______, after
stress relieving, but before hydrotest.
VT & MT or PT
86. Repaired shell vertical joints shall have ______ radiograph taken in every joint.
1
87. A name plate for a reconstructed tank shall have:
Design condition listed
88. The minimum length of readable RT film according to API 653 is?
6”
89. When the corrosion rate of a tank is known the interval between taking UT thickness
measurements shall be the smaller of RCA/2N or:
15 years.
90. If the corrosion rate is not known, what is the in-service UT interval?
5 years.
91. General inspection reports shall include:
Metal thickness measurements, conditions found, repairs, any settlement
measurements, and recommendations.
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7. API 650 & 653
PRACTICE QUESTIONS (CLOSED BOOK)
92. Peaking shall not exceed ½” when measured with:
A horizontal sweep board 36” long and made to the true outside radius of the
tank.
93. Routine in-service inspection includes:
Visually checking the exterior tank’s surface for leaks, shell distortions, signs of
settlement, signs of corrosion, condition of foundation, condition of paint,
condition of insulation system, and condition of appurtenances.
94. Which of the following is an alteration?
Addition of a 14” diameter nozzle.
95. Corroded roof plates shall be repaired or replaced, when the:
Average thickness is less than 0.09” in a 100 square inch area.
96. Hydrostatic test stress for a new tank is based upon:
The lesser of ¾ the yield stress or 3/7 the minimum tensile stress of the tank’s
material of construction.
97. If the number of elevation measurement points is determined by N = D/10, how many
measurement points are necessary on a 50 feet diameter tank?
8
98. The joint between the new material of an insert plate and the old material of the
existing tank shell plate shall be:
Butt welded.
99. It has been determined that L=32” in a corroded area of a tank 125’ in diameter and
40’ high. Sixteen UT readings are taken every 2” over the length of “L”. The readings
are as follows: 0.42, 0.32, 0.38, 0.30, 0.28, 0.25, 0.26, 0.25, 0.23, 0.29, 0.26, 0.31,
0.37, 0.34, 0.33, and 0.39. Determine t1(tavg). Round to the nearest hundredth.
0.31”
100. The critical zone for repairs to tank bottoms is that portion of the bottom or
annular plate within ______ of the inside edge of the shell, measured radially inward.
3”s
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