API 650 Flashcards
API-650 applies only to tanks whose entire bottom is uniformly supported and tanks in ___ that have a maximum operating temperature of _____°F.
Non-refrigerated service and temperature not exceeding 200°F
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?
Maximum pressure shall not exceed the weight of the roof plates
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?
Yes only if the material passes the tests prescribed in Appendix N (Use of New Materials That Are Not Identified)
What is the maximum permitted underrun for shell, roof, and bottom plates?
0.01 inch from the computed design thickness or minimum permitted thickness
Shell plates are limited to what maximum thickness?
Shell plates are limited to a maximum thickness of 1.750 inches
In situations where it is not possible to obtain full size specimens, what is the required width along the notch for subsize specimens?
80% of the material thickness
The minimum size of fillet welds shall be as follows: and on plates more than 5 mm (3
/16 in.) thick?
(not for shell to bottom weld)
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.).
For lap-welded joints that are tack welded, what is the minimum amount of lap permitted?
The joint shall be lapped at least 5 times the nominal thickness of the thinner plate
Vertical shell joints shall be?
butt joints with complete penetration and complete fusion
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.
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
12 inches
What is the maximum size of fillet weld permitted in the attachment between the lowest course shell plate and the bottom plate?
1/2 “
According to API-650, tanks meeting the minimum requirements of the standard may be subjected to a partial vacuum of _____
One inch of water pressure
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.
one test shall be conducted for each vertical weld, and one test shall be conducted for each 30 m (100 ft) of circumferential weld.
All bottom plates shall have a corroded thickness of not less than?
than 6 mm (0.236 in.)
How far must annular bottom plates project outside the shell? and trimmed
Annular bottom plates shall project at least 2 inches outside the shell
Trimmed bottom plates shall project at least 1 inches
outside the shell
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
24”
the shell plates shall have a minimum nominal width of
1800mm (72 in.).
Nozzles and manholes should not be placed in shell weld seams and reinforcing pads for nozzles and manholes should not overlap plate seams …..
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
What is the maximum size un-reinforced opening permitted in flat cover plates without increasing the thickness of the cover plate?
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
What is the maximum size opening that may be placed in a cover plate?
12”
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?
1100°F to 1200°F for 1 hour per inch of shell thickness
minimum length of weld (remote from intersections) that must be shown on a radiograph?
6”
design metal temp is based on the lowest one day mean temperature of___-
8C / 15F ABOVE lowest one day mean temp
telltale hole inspection pressure?
15 psig of pnematic
APi 650 is for what?
atmosphere storage tanks
qualification of welds for construction of api650 is govern by
ASME IX
api650 covers
cylindrical, aboveground, welded storage tanks
external floating roof shall be provided with atleast one manhole with min of what dimension
24”
full fillet weld definition
legs equal to thickness of the THINNER plate
self supporting cone roof
formed to approx. the surface of a right cone AND supported at periphery
below what temp should all design metals for all weld material require impact test?
below 20F
what type of bottoms exceeding 100 feet and above 200 F
butt welded annular bottom plates
sketch plates must project beyond the shell to bottom fillet
at least 2” for API650, atleast 1” for API653
pinhole leak or porosity in tank bottom joint may be repaired
applying additional weld bead over area
plates thickener than what size should be normalized or quenched?
1.5”
lower shell course thickness shall be _____ than the thickness required of the upper shell course
NO LESS
tack welds should be made in accordance with with ASME Section IX
for butt and fillet welds
groove welds , root opening shall not be less than?
1/4”
top decks of external floating roof (double deck/ pontoon type) designed with what slope?
1 in 64
underrun not permitted over what thickness from the computed design thickness
0.01 “`
bottom and shell plates have a width of?
72”
out of plumbness shall not exceed ?
1/200 tank height
charpy V notch impact performed when?
after heat treatment
define full fillet welds
legs equal the thickness of the thinner plate
Groups Iv, Iva, v, vi shell to bottom welds made with how many passes
made with min of 2 passes
NDE - method of examination shall be in accordance
ASME V
NDE - shall be performed in accordance / acceptance standards (NDE is acceptable/unaccepable)
ASME VIII
impact tests of the weld metal shall be made for
all procedures at what temp?
When the design metal temperature is below –7 °C (20 °F),
name plates height?
5/32”
max plumpness’ for new / existing tanks
1/200 AND 1/100
RT - the number of spot radiographs required herein shall be applicable on a ____ tank basis
per tank
