API 653 Flashcards
Learn API 653
API 653 covers tanks built to what API codes?
API 650 & 12C 653 - 1.1.1
API 653 recognizes FFS API 579 assesment T/F?
TRUE 653 - 1.1.6
If regulations of 653 are more strict than local AHJ regulations, which governs?
API 653 653 - 1.3
What is an alteration?
Any work that changes physical dimensions/configuration 653 - 3.1
Where is the critical zone?
annular plate within 3” of the inside of shell 653 - 3.10
What is considered a major repair/alteration?
shell penetration > NPS 12; bottom penetration within 12” of shell; R&R shell plate with any dimension >12”; R&R annular plate with any dimension >12” 653 - 3.20
What is considered a major repair/alteration?
removal of vert. 12” weld on shell plates or on annular ring; a whole new bottom; R&R 50% weld between shell/annular ring; jacking tank shell 653 - 3.20
What is considered a repair?
work necessary to restore a tank to safe operation (includes major repair scope) 653 - 3.26
What is considered a repair organization?
owner/operator who repairs/alters to 653; contractor who’s quals are acceptable to owner/user and 653; one who is not prohibited by AHJ and 653 653 - 3.27
What is a storage tank engineer?
one or more persons acceptable to owner/user regarded as composite of all entities to properly assess req’s 653 - 3.30
Roof plates corroded to what condition SHALL be replaced?
0.09” avg thickness in any 100 in^2 or holed through 653 - 4.2.1.2
When evaluating alterations to a tank roof, what standard applies?
Current applicable standard API 650 Annex F 653 - 4.2.4.1
Before changing service to an elevated temp of >200F, what std shall apply?
API 650, Annex M - 653 - 4.2.4.3
Before changing service to a lower temp, what std shall apply?
Currrent applicable std 653 - 4.2.4.4
What are options if req’s of 653 cannot be satisfied?
Damaged areas shall be repaired; liquid level reduced; tank retired 653 - 4.3.1.5
Shell corrosion - critical Length L is determined by what formula, not to exceed?
L = 3.7sqrt(DT2) D = tank diam in FEET; T2 least thickness in INCHES; L max = 40” 653 - 4.3.2.1
Shell corrosion - widely scattered pits may be ignored, provided that?
No pit is >50% of Tmin, sum of pits vert dim’s
Shell corrosion - Tmin shall not be less than X inches for any tank course?
0.1” 653 - 4.3.3.1
Shell welds - cracks in the shell to bottom weld SHALL be removed (T/F)?
TRUE 653 - 4.3.6
Bottom - assesment period shall be ?
Less than or = to shell interval
Bottom - Tmin for bottom plate (minimum remaining thickness)
Reference 653 - 4.4.5.1
Bottom - if mim thickness will be
Lined, repaired, replaced or interval to next internal insp. Reduced 653 - 4.4.5.3
Bottom - critical zone Tmin SHALL be the smaller of?
50% of original thickness or 50% of Tmin of bottom shell; but not less than 0.1” 653 - 4.4.5.4
Bottom - thickness of projection of bottom plate beyond shell shall not be
0.1” thick and horiz. projection beyond shell shall be >= 3/8” 653 - 4.4.5.7
Foundation - principle causes of foundation deterioration include?
settlement, erosion, cracking, and conrete deterioration 653 - 4.5.1.1
Brittle Fracture - once a tank has withstood X & Y, the risk of brittle fracture is low?
Combined effects of max liquid level and lowest operating temp 653 - 5.2.2
Brittle Fracture - any change in service must be evaluated for brittle fracture risk (T/F)?
TRUE 653 - 5.2.3
Brittle Fracture - if shell is no thicker than 0.25, 0.5, 0.625 or 0.75 , brittle fracture risk is low?
0.5” 653 - 5.3.5
Brittle Fracture - no known brittle fracture above shell temp of 32F, 50F, 60F, or 70F?
60F 653 - 5.3.6
Inspection - routine in-service visual inspections shall be made every week, month, or year?
Shall not exceed one month interval 653 -6.3.1.2
Inspection - Tanks shall be given a visual external by an AI at least?
Every 5 years or RCA/4N years
Inspection - UT of shell thickness - when shell corrosion rate is not known, UT shall be done?
At least every 5 years 653 - 6.3.3.2
Inspection - UT of shell thickness - when shell corrosion rate is known, UT shall be done?
15 years or RCA/2N years, whichever is smaller 653 - 6.3.3.2
Inspection - Initial internal interval shall not exceed 3, 5, 10 or 15 years?
10 years, unless safeguards are added per Table 6.1 653 - 6.4.2.1.1
Material - new materials used for repair/alt/reconstruction shall conform to?
Current applicable standard 653 - 7.2
Material - shell/bottom plate material shall be identified by?
Original contract drawings, API nameplates, or other suitable docs 653 - 7.3.1
Material - flange mat’l shall meet minimum req’s of as built or current applicable std?
The “as built” standard 653 - 7.3.3.1
Design - shell thickness design shall be based on numbers taken within 30, 60, 90 or 180 days?
Within 180 days 653 - 8.4.1
Design - shell penetrations shall be design/welded to the as built or current applicable std?
Current applicable std 653 - 8.5.1
Tank repair - all repair work must be authorized prior to work by whom?
Authorized Inspector OR Tank Engineer 653 - 9.1.3
Tank Repair - Alterations must be approved by the AI, Tank Engineer or both?
Tank Engineer only 653 - 9.1.3
Tank Repair - Inspection hold points will be designated by AI, Tank Engineer or both?
AI only 653 - 9.1.3
Tank Repair - limited or routine repairs may be authorized by AI, Tank Engineer or both?
AI may authorize repairs provided no hydro or engineering evaluation is req’d. 653 - 9.1.3
Tank Repair - design, work execution, materials, procedures, NDE must be approved by AI, Tank Engineer or both?
AI or Tank Engineer 653 - 9.1.4
Tank Repair - Repair/alteration work shall be approved at HOLD points/after work completion by AI, Tank Eng or both?
AI or Tank Engineer 653 - 9.1.4
Shell repair - minimum dimension for a replacement shell plate is 4”, 6”, 12”?
12” or 12 x thickness of shell, whichever is greater 653 - 9.2.2
Shelll repair - replacement shell plates may be what shapes?
circular, oblong, square w/rounded corners, rectangular w/rounded corners 653 - 9.2.2.1
Shell repair - prior to welding new vertical joints, the horiz. Welds shall be cut 3”, 6”, 9” or 12” beyond the joint?
12” beyond vertical joint and vert. must be done before horiz. 653 - 9.2.2.2
Door sheet - if a vert cut crosses existing horiz weld, the back gouged root pass and final pass shall be PT, MT or both?
PT or MT 653 - 9.2.4.5
Door sheet - if a vert cut crosses existing horiz weld, the existing seam shall be MT, PT or both for how far on both sides?
MT or PT for 6” on both sides 653 - 9.2.4.5
Shell repairs - lap welded patch plates are acceptable on butt welded, lap welded, riveted tank or all?
All tanks when specified by owner 653 - 9.3.1
Shell repairs - lap welded patch plates shall not be used on shells > than 0.375”, 0.5”, 0.625” or 0.75”?
0.5” thick 653 - 9.3.1.2
Shell repairs - repair plate corners shall be rounded to a minimum radius of 0.5”, 1”, 1.5” or 2”?
2” minimum radius 653 - 9.3.1.4
Shell repair - repair plate may cross any ground butt welded seam provided it overlaps minimum 3”, 6”, 9” or 12”?
6” beyond weld seam 653 - 9.3.1.5
Shell repair - maximum dimension of a repair plate is 2’x3’, 3’x4’, 4’x6’ or full shell course height x 8’?
4’x6’ 653 - 9.3.1.7
Shell repair - the minimum dimension of a repair plate is 4”, 6”, 8”, or 12”?
4” minimum dimension 653 - 9.3.1.7
Shell repair - repair plate shall conform to as-built std with a joint efficiency or 0.35, 0.5, 0.7, or 0.85?
Joint efficiency not exceeding 0.7 653 - 9.3.2.3
Shell repair - repair plate shall conform to as-built std with a joint efficiency or 0.35, 0.5, 0.7, or 0.85?
Joint efficiency not exceeding 0.35 653 - 9.3.3.1
Shell penetration - reinforcing plates may be added to both outside and inside of tank provided nozzle projection (T/F)?
TRUE - must have adequate nozzle projection into tank 653 - 9.7.3
Shell penetration - penetrations larger than NPS 1.5, 2, 4, or 6” shall be installed with an insert plate
NPS 2” 653 - 9.8.6
Shell penetration - completed splice welds on bottom plate when installing a new bottom shall be PT, MT or both?
MT 653 - 9.9.4 c)
Tank Bottom - min dimension for a welded on patch plate that overlaps a bottom seam shall be 4”, 6”, or 12”
12” 653 - 9.10.1.1