lockhart day 4 training Flashcards
PQR must be….
signed and dated
WPS must be qualified by
manufacturer or contractors
WPS provides what
direction to welder for making production welds
WPS must address (3)
- essential
- non essential variables
- supplementary variables ( if required)
PQR does what?
establish the properties of the weld ONLY not welder
PQR must address (2)
- essential
- supplementary variable (if required)
WPS qualified in 1962 or later
can still be used
WPS qualified in 1962 or prior
can be used ONLY if all 1962 requirements are met
interpass temp?
highest temp allowed in weld or weld joint between pass
lower transformation temp is what and what happens?
1330F - ferrite begins to transform into austenite
upper transformation temp is what and what happens?
1600F - from ferrite to austenite is COMPLETE
who responsibility to qualify WPS and welders?
organization
who maintain welding records?
manufacturer shall maintain results of WPS and welders qualification
How often to do settlement sruvey? (3)
before , during, and after hydro
how long must radiographs be retained
1 year
How often must API653 be renewed?
3 years
how often an inspector required to be recertified
6 years
amount of time involved in inspection to keep API653 cert.
20%
When is CUI most severe?
170-230F
Where is MIC often found?
stagnant or low flow areas
How can caustic stress corrosion cracking be preventwed
PWHT at 1150F
Where is sulfuric acid most affect area for severe corrosion in CS?
HAZ
why is P number used?r
reduce the # of welding procedure qualification
Why is F # used?
reduce # of welding procedure/performance qualification
tension test is to determine?
ultimate stregnth
Requirement of tension test for base/weld metal and if 2 metals
- Base metal at least 95%
- Weld metals - 100%
- if 2 metals then weakest of the 2 base metals
Guided bend test to determine
ductility / soundness of groove weld joints
RT and UT can replace what test?
bend test
what are the requirement thickness for plates/pipe for «1’ and >1” for test specimen
«_space;1” = full thickness
>1” = full thickness OR multiple specimen
reduce sections for plates/ pipes requirement?
- plates = all thickness
2. pipe > 3”
what happens to CS with sulfuric acid if flow rate is 5fps?
increase CR when velocity is at 2-3 fps
What happens when water is mixed with sulfuric acid
diluted acid causes heat to be release, increasing CR
How to prevent sulfuric acid?
add caustic to neutralize
Reason for geodesic dome on a tank?
prevent vapor loss to eliminate the need for water draw off
Coating may affect UT reading, what to do for UT?
compensate for the coating
recommend size of coupon to remove for testing soil corrosion?
12” min
VI angle min?
min 30 degrees
penetrating oil is spray on the outside of the shell to weld for a test, what is another name?
wicking
what size discontinuity is allowed for bend test?
Less than 1/8” in any direction on convex surface
Are open discontinuity at corner acceptable?
all unless > 1/8”
What is VI used to qualify for?
performance not PQR
When are welds to be inspected ?
after weld and before specimen is removed
What can RT and UT substitute for?
groove bend test / mechanical test
why is 2 pass welding recommend for seal welding leaking rivets?
allow for poor first pass due to hydrocarbon contamination
what are the 4 components of a corrosion cell
ACME , anode , cathode, metallic path, electrolyte
soil rate corrosion increase at what pH and decreases at what pH?
- increase when pH <5
2. decrease when pH >8
CR of bottom steel may double with what temperature?
may double with 18F above 77F
require overlap for a single welded bottom plate lap joint?
not to exceed 1”
min offset of vertical welds in adjacent shell courses?
min 5t (t = thickness of thicker plate)
required size of fillet weld for lapped bottom plates?
full fillet welds
min distance required between 3 plate lap joints with tank shell, annular plate
12 “
require type of joint for annular plate?
butt weld
what is required radially distance from the annular plate to shell joint and any lap welded bottom joint?
24”
production welds must be qualify by (3)
- RT or UT
- VT and mechanical
- VT and RT/UT
WPQ is welded in accordance with a
WPS
can preheat/PWHT be omitted for WPQ if required by WPS?
yes can be omitted
What welds cannot be qualified with RT. (2)
- GMAW-S and
2. P21-P25, 51-53, 61,62 for all process except GTAW
UT is limited to what thickness for weld qualification
1/4”, cannot UT under 1/4”
min length required for RT to qualify a welder
6”
min length required for RT to qualify a welding operator
3 feet
requalification test if fail VT?
2 coupons, 1 for VT and 1 bend
requalification test if fail bend test?
2 coupons, both must pass bend or RT
requalification test if fail RT ?
2 coupons , retest RT twice the required length
when does welder qualification expires (2)
- welder has not use process for 6months
2. reason to question welders ability
how to requalify welding if qualification expires?
weld coupon ANY size/position then, VT/Band or RT
WPQ must contain? (6)
- variables used
- essential variables
- type of test
- test results
- ranges qualified
- certifications
What is require PWHT for insert plates and penetration >1”
1100-1200 F
min allow sloped for cone roof
1:16
max allow slope for frangible roof?
2:12
max allow diameter requirement on surface porosity cluster ?
3/32”
min distance of a surface porosity?
4”
what design metal temp are vertical shells welds required to be impact tested for a PQR?
Less than 50F
WPS contains? (3)
- essential
- non essential
- supplementary if required
PQR contains? (4)
- essential
- supplementary if required
- range of variables used to make the coupon
- must be certified by manufacturer/contract (signed/dated)
When does WPS needs to be requalified?
changes to essential and supplementary
WPS must be readily available when?
at the fabrication site for review
PQR is to?
record of the welding data used to make the test coupon and test results
When is PQR recertified?
when ANY changes (except for editorial changes)
PQR must be available for whom?
AI not the welder
How many PQR for a wPS?
could be multiple
What tests can NOT be done for WPS/PQR
RT/VT
What test to do on WPS/PQR?
bents and tension test
WPQ NDE test requirements
VI/Bend, RT/UT
when is preheat done ? (2)
- when 0-32F
2. base metal >1”
preheat temp requirement? (temp and distance)
140F and within 3”
preheat temp at 1.5” thickness
200F
when low h2 electrode required? (3)
- t >1/2” - group 1-3
- Group Iv-vI
- temp attachments to welded material in IV-VI
reconstructed tank / new tank plumpness?
- 1/100 , max 5”
2. 1/200
what is definition of plumpness
offset of the top of the shell to the bottom of the shell
WPS / PQR is qualified by what code?
ASME Section IX
Welders are qualified by
ASME Section IX
NDE procedure accordance for RT/MT/UT/PT?
ASME section V
VT procedure accordance?
Manufacturers requirement
Personnel qualification for RT/UT
Level II/III
Personnel qualification for MT/PT
competent in technique
When is PT/MT used? (4)
- cavities from gouging/grinding
- nozzle to shell weld
- repads
- welds thicker than 1”
NDE used for new shell to bottom welds? (4)
- diesel oil
- right vacuum box
- pressuring cavitywith 15 psig
- LT
NDE used for new bottom (3)
- vaccum box
- tracer gas
- hydro with 6” of level
how many settlements are needed for NEW tanks?
6, before, .25, .5, .75, 1, and 24hours and after tank is empty
RT extent for penetration using insert plates?
100% RT