API 650 Flashcards

Welded Tanks for Oil Storage

1
Q

What is the minimum required overlap for a single-welded bottom plate lap joint?

A

Lesser of 1” or 5 times nominal thickness

API 650 5.1.3.5

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2
Q

What is the minimum offset of vertical welds in adjacent shell courses?

A

5t of the thicker plate joined

API 650 5.1.5.2b

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3
Q

What is the required size of the filler weld for lap tank bottom plates?

A

Full Fillet Weld

API 650 5.1.5.4.1

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4
Q

What is the minimum distance required betwen 3-lap bottom plate joints?

A

12”

API 650 5.1.5.4.2

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5
Q

What is the minimum disntace required between a 3-lap bottom plate join and the tank shell?

A

12”

API 650 5.1.5.4.2

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6
Q

What is the minimum disntace required between a 3-lap bottom plate join and annular plate to bottom plate joint?

A

12”

API 650 5.1.5.4.2

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7
Q

What is the required joint type for connecting annular plates?

A

Butt Weld

API 650 5.1.5.4.3

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8
Q

What is thr required radially distance from the annular plate-to-shell joint and any lap-welded bottom joint?

A

24”

API 650 5.1.5.4.3

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9
Q

What is the minimum required thickness of bottom plates of a new tank?

A

0.236” (1/4”)

API 650 5.4.1

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10
Q

What is the minimum external projection required of a bottom plate for a new tank?

A

Greater of 2” or 1/2” outside the shell to annular plate fillet weld

API 650 5.4.2 & 5.1.5.7d

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11
Q

What is the minimum required slope of tank bottom?

A

1:120 upward toward the center

API 650 5.4.4

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12
Q

What size of nozzle in a shell, never requires a repad?

A

≤ NPS 2

API 650 5.7.2.1

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13
Q

What is the required PWHT temperature for shell openings in insert plates or shells > 1” htick in material group I thru IIIA?

A

1100°F to 1200°F

API 650 5.7.4.2

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14
Q

What is the minimum allowed slope for a cone roof?

A

1:16

API 650 5.10.4.1

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15
Q

What is the maximum allowed slope for a frangible roof?

A

2:12

API 650 5.10.2.6(a)(1)

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16
Q

When using penetrating oil to test the shell-to-bottom weld, what is the minimum required dwell time?

A

4 hours

API 650 7.2.4.1d

17
Q

What is the required pressure for leak tested a repad?

A

15 psig

API 650 7.3.5

18
Q

At what thickness are vertical shell joint welds required to be 100% radiographed?

A

> 1”

API 650 8.1.2.2c

19
Q

Acceptance criteria for radiographs comes from what code?

A

UW-51(b) of ASME Section VIII, Div 1

API 650 8.1.5 & API 653 12.1.1.3

20
Q

What is the required interval for vision and color contrast eye exams for NDE personnel?

A

Annual

API 650 8.2.3a 8.5.1a

21
Q

What is the maximum allowed udercut for vertical joints, nozzle attachment welds and shell-to-bottom welds?

A

1/64”

API 650 8.5.2b

22
Q

What is the maximum allowed udercut for horizontal welds and annular ring welds?

A

1/32”

API 650 8.5.2b

23
Q

What is the maximum allowed diameter of a surface porosity cluster?

A

3/32”

API 650 8.5.2c

24
Q

What is the minimum required distance between surface porosity clusters?

A

4”

API 650 8.5.2c

25
Q

What is the typical size of a vacuum box?

A

6” x 30”

API 650 8.6.1

26
Q

What is the required vacuum pressure for a vacuum box test?

A

3 to 5 PSI

API 650 8.6.3

27
Q

What is the required interval for vision exams for vacuum box tester?

A

Annual

API 650 8.6.4a

28
Q

What is the minimum required overlap of previously tested surfaces when vacuum box testing?

A

2”

API 650 8.6.5

29
Q

What is the temperature limits for vacuum box testing?

A

40°F to 125°F

API 650 8.6.6

30
Q

What is the minimum required light intensity for vacuum box testing?

A

100’ candles

API 650 8.6.7

31
Q

What is the required amount of time that the vacuum must be maintined during a vaccum box test?

A

5 seconds of time required to view the area under the box

API 650 8.6.8

32
Q

At what design metal temperature are vertical shell welds required to be impact tested?

A

<50°F

API 650 9.2.2.3

33
Q

Per API 650, welder stencils shall be stamped at what interval?

A

Less than or equal to 36”

API 650 9.4

34
Q

What is the minimum size of the letters on a nameplate?

A

no less than 5/32”

API 650 10.1.1

35
Q

How far above the ground surface should the tank bottom be built?

A

12”

API 650 Annex B.3.1

36
Q

What is the recommended thickness of the sand bed under the bottom of the tank?

A

3” to 4”

API 650 Annex B.3.2

37
Q

What is the maximum spacing between electrical shunts on floating roofs?

A

No more than 10’

API 650 Annex C.3.1.6