API 650 Flashcards
Welded Tanks for Oil Storage
What is the minimum required overlap for a single-welded bottom plate lap joint?
Lesser of 1” or 5 times nominal thickness
API 650 5.1.3.5
What is the minimum offset of vertical welds in adjacent shell courses?
5t of the thicker plate joined
API 650 5.1.5.2b
What is the required size of the filler weld for lap tank bottom plates?
Full Fillet Weld
API 650 5.1.5.4.1
What is the minimum distance required betwen 3-lap bottom plate joints?
12”
API 650 5.1.5.4.2
What is the minimum disntace required between a 3-lap bottom plate join and the tank shell?
12”
API 650 5.1.5.4.2
What is the minimum disntace required between a 3-lap bottom plate join and annular plate to bottom plate joint?
12”
API 650 5.1.5.4.2
What is the required joint type for connecting annular plates?
Butt Weld
API 650 5.1.5.6
What is thr required radially distance from the annular plate-to-shell joint and any lap-welded bottom joint?
24”
API 650 5.1.5.4.3
What is the minimum required thickness of bottom plates of a new tank?
0.236” (1/4”)
API 650 5.4.1
What is the minimum external projection required of a bottom plate for a new tank?
Greater of 2” or 1/2” outside the shell to annular plate fillet weld
API 650 5.4.2 & 5.1.5.7d
What is the minimum required slope of tank bottom?
1:120 upward toward the center
API 650 5.4.4
What size of nozzle in a shell, never requires a repad?
≤ NPS 2
API 650 5.7.2.1
What is the required PWHT temperature for shell openings in insert plates or shells > 1” htick in material group I thru IIIA?
1100°F to 1200°F
API 650 5.7.4.2
What is the minimum allowed slope for a cone roof?
1:16
API 650 5.10.4.1
What is the maximum allowed slope for a frangible roof?
2:12
API 650 5.10.2.6(a)(1)
When using penetrating oil to test the shell-to-bottom weld, what is the minimum required dwell time?
4 hours
API 650 7.2.4.1d
What is the required pressure for leak tested a repad?
15 psig
API 650 7.3.5
At what thickness are vertical shell joint welds required to be 100% radiographed?
> 1”
API 650 8.1.2.2c
Acceptance criteria for radiographs comes from what code?
UW-51(b) of ASME Section VIII, Div 1
API 650 8.1.5 & API 653 12.1.1.3
What is the required interval for vision and color contrast eye exams for NDE personnel?
Annual
API 650 8.2.3a 8.5.1a
What is the maximum allowed udercut for vertical joints, nozzle attachment welds and shell-to-bottom welds?
1/64”
API 650 8.5.2b
What is the maximum allowed udercut for horizontal welds and annular ring welds?
1/32”
API 650 8.5.2b
What is the maximum allowed diameter of a surface porosity cluster?
3/32”
API 650 8.5.2c
What is the minimum required distance between surface porosity clusters?
4”
API 650 8.5.2c
What is the typical size of a vacuum box?
6” x 30”
API 650 8.6.1
What is the required vacuum pressure for a vacuum box test?
3 to 5 PSI
API 650 8.6.3
What is the required interval for vision exams for vacuum box tester?
Annual
API 650 8.6.4a
What is the minimum required overlap of previously tested surfaces when vacuum box testing?
2”
API 650 8.6.5
What is the temperature limits for vacuum box testing?
40°F to 125°F
API 650 8.6.6
What is the minimum required light intensity for vacuum box testing?
100’ candles
API 650 8.6.7
What is the required amount of time that the vacuum must be maintined during a vaccum box test?
5 seconds of time required to view the area under the box
API 650 8.6.8
At what design metal temperature are vertical shell welds required to be impact tested?
<50°F
API 650 9.2.2.3
Per API 650, welder stencils shall be stamped at what interval?
Less than or equal to 36”
API 650 9.4
What is the minimum size of the letters on a nameplate?
no less than 5/32”
API 650 10.1.1
How far above the ground surface should the tank bottom be built?
12”
API 650 Annex B.3.1
What is the recommended thickness of the sand bed under the bottom of the tank?
3” to 4”
API 650 Annex B.3.2
What is the maximum spacing between electrical shunts on floating roofs?
No more than 10’
API 650 Annex C.3.1.6
