API 653 Chap 12 - Examination / Testing Flashcards
What is Annex G
guidance on MFL
What kind of NDE to perform on cavities resulting from gouging or grinding operation to when remove attachment welds of existing reinforcing paltes?
MT or LP
Type of NDE for completed welds?
MT or LP
What additional exam for unknown toughness having a t > 1/2”?
Fluorescent MT and/or UT
NDE for completed welds of stress relieved?
MT or LP after stress relieve BEFore hydro
NDE for complete repair butt / fillet welds?
Butt Weld - full length by RT or UT
NDE - Removal of attachments?(exclude shell to bottom welds)
Visual
NDE - new permanent attachments? (exclude shell to bottom welds)
MT or LP
NDE - new welds attaching existing shell plate to new or existing? and if t>1”?
RT, root/final pass full length by MT or LP
NDE for NEW shell to bottom joint welds? (3)
- Full length by using a right angle vacuum box and a solution film
- applying light diesel oil
- tested by pressurizing the volume with 15 PSIG (air) and applying a solution film to inside and outside welds.
NDE for existing weld shell to bottom joint ?
visual + MT or LP, for full length under a Weld on patch plate. An additional 6” of each side of the weld shall be examined.
NDE - critical zone welding , bottom repair welding
root/final pass full length by MT or LP
NDE for shell plate repairs, by weld deposit, lap welded patches?
visual + MT or LP
NDE for floating roof ? (2)
- VT from top and bottom
2. air leak, vacuum box, penetrating oil, tracer gas, (annex f)
How many RT is need for vertical joints?
- for new replacement shell to new shell plates
- new replacement to existing
- repair joints in existing?
- 0
- 1 additional
- 1 additional
How many RT is need for horizontal joints?
- for new replacement shell to new shell plates
- new replacement to existing
- repair joints in existing?
- 0
- 1 for each 50 ft additonal
- 1 for each 50 ft addtional
How many RT is need for vertical/horizontal joints?
- for new replacement shell to new shell plates
- new replacement to existing
- repair joints in existing?
- 0
- each intersection
- all repair section
What does RT additional mean?
In addition required by API 650 for new construction
What does API650 new construction states for RT for vertical? for «3/8”
- butt weld joints «_space;3/8”, one spot first 10 feet of completed vertical joint, thereafter 100ft , 25% at intersection + spot RT
What does API650 new construction states for RT for horizontal?
butt weld joints «_space;3/8”, one spot first 10 feet of completed vertical joint, thereafter 200ft.
What does API650 new construction states for RT for vertical? for»_space;3/8” but «_space;1”
following «3/8” + spot RT at the bottom course + spot RT at intersections + «3/8” requirements
What does API650 new construction states for RT for vertical? for»_space; 1”
full length RT + everything in»_space;3/8 but «1”
RT record of all repair welds shall be marked with?
“R”
RT requirement for circular replacement plates?
1 RT regardless of thickness, t >1” weld full length RT
shell plate and door sheet welds RT requirement?
all junction need to be RT, 100% if defects are found
square and rectangle RT requirement?
at least 1 RT in vertical joint, horizontal, corner
min diagnostic length of RT?
6”
full hydro test held for how many hours?
24 hours
When should hydro be performed?
- any reconstructed tank
- major repairs/alteration
- severity of service increase
When do you not need a hydro ? (5)
If engineer + owner signs off , AND
- new material meet section 4 API650 requirement
- no impact test needed
- not exceed 7000 PSI
- full penetration butt weld
- RT root/final pass weld
shell to bottom weld repair requirements (2)
- weld can be removed and replace as long as it meet 650 5.1.5.7
- weld on one side of shell can be completely removed not exceeding 12”.
tank settlement survery?(5)
- should be uniformly distributed, around circumference
- N=D/10,
- rounded to the EVEN number
- min is 8 points,
- max spacing is 32feet
