Weld bead misalignment 6

[cardin]

Is there anyone that can help me on this matter.

I have a weld (pressure vessel long. seam)that has misaligned weld beads.
I can't find anything on the allowable misalignment of weld beads.
The have fusion and no fusion errors are found.

Is there anyone that can help me on this question. Where can i find information for the acceptance criteria?
European standard EN13445 does not give me a clear requirement perhaps some other standards are more helpfull (ex. ASME)
img

https://res.cloudinary.com/engineering-com/image/upload/v1499940955/tips/weld_bead_error_qxbxon.jpg

]

 

[LittleInch]

How on earth did they weld that? It looks like the root gap was reversed so there is no root.

Unless specifically shown on the WPS, I suspect that this is a weld which has no WPS or WPQT.

Ask for the WPS that matches the seam weld as you've shown it. When it doesn't appear tell them to cut the weld out.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[cardin]

How they did get it so misaligned is not clear to me.
It was a standard 2 sided long. weld prepared correctly.
The welder clearly started too much to one side and did not correct / notice this.

But the tensile test is good over min. required value and RT did not show any problems either.
Is am reluctant to accept the error, but can not find a ground based on the standard (EN13445) or other standards.
None of the clearly states that this error can't be accepted or how much misalignment is acceptable.

 

[weldstan]

Assuming that a WPS was required, the joint design should have been stated. I would assume that the joint shown was not in accordance to that of the WPS. I have seen somewhat misaligned weld profiles on Long seam welded pipe but not nearly as you have depicted.

 

[boofi]

But the tensile test is good over min. required value and RT did not show any problems either.
Is am reluctant to accept the error, but can not find a ground based on the standard (EN13445) or other standards.

Sometimes you just have to go with your gut. If it's not what you/your company asked for, and they can't prove that it's qualified, then I'd be very skeptical too. How long as this vessel been in service?

 

[mk3223]

Agreed not to accept the weld simply because the joint configuration wasn't follow the WPS.
IMO, this weld with large overlapping portion may require different interpose temperature control which might not specified in the existing WPS.

 

[gtaw]

If the code has no criteria, what is the basis of rejecting the completed weld or the weld preparation?

If the joint is complete joint penetration, if the completed weld has no unacceptable discontinuities, if there is no criteria provided by the applicable code or standard, there is little basis for rejecting the weld.

One must remember the purpose of a groove preparation. As far as I know, the purpose of the preparation is to provide sufficient access and appropriate clearances needed to ensure the welder can deposit sound weld metal.

The joint detail is considered a nonessential variable by the ASME B&PV code. At best, the contractor should revise the WPS to include the joint detail, but most WPSs I review rarely include actual details of the groove preparation.

In this case it appears the weld is sound as demonstrated by the acceptable radiograph. Apparently, the mechanical properties were developed as demonstrated by the tensile tests demonstrated. That being the case, what is the basis of rejecting the completed weld? Is the reason for rejection is a personal preference? Shaky grounds at best.

Best regards - Al

 

[DekDee]

Have to agree with Al - it is a metallurgically sound weld with complete penetration as evidenced by the RT.
Regards,
Shane

 

[metengr]

Remember, the Code provides minimum requirements. If this weld met the Code minimum requirements, it is acceptable unless you have your own engineering specification that requires a specific groove weld prep.

 

[LittleInch]

But if this is a pressure vessel weld, how have you managed to get a tensile test?

did it do other normal WPS tests?

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[DekDee]

This seems like a bit of over-reaction.
What was the original joint configuration ? (the OP has told us the weld is completed so I presume he is looking at two weld "caps" that are not in alignment.)
If the configuration was as per the drawing prior to welding why were the OP's concerns not flagged to the relevant parties prior to welding ?

If the weld was backgouged and the operator was off centre but still managed to locate the sound weld metal does it matter ? - as Al stated the purpose of the groove is to enable access to the welder to complete the weld.

There are too many scenarios (if we are talking about a completed weld) to be able to comment.
As an example - a double vee weld has undercut on one completed reinforcement so an additional filler weld bead is placed.
The plate is then turned and second side welded with undercut again but on the opposite toe to side one - an additional filler weld bead is placed.
You now have an apparent weld misalignment exactly the same as the OP ?
Cheers,
Shane

 

[r6155]

What happened with this?:
ASME VIII Div 1 UG-90 INSPECTION AND TEST (12) examination of all parts prior to joining to make certain they have been properly fitted for welding or brazing and that the surfaces to be joined have been cleaned and the alignment tolerances are maintained (UW-31, UW-32, UW-33, and UB-17);

Regards
r6155

 

[jtseng123]

UW-31, 32, 33 have nothing to do with the groove misalignment.
The purpose of welding is to demonstrate it has the same or better mechanical property than base metal, and no defect or if any defects, accepted by Code. Perform hardness test as required so it is still ductile. If having doubt, perform PWHT. Hydrotest and then ready for service. The as-welded condition is acceptable to me. Pretty much cowboy style since I am in Texas, the energy state.

 

[r6155]

@ cardin
Please, can you tell us the thickness of base metal?

Regards
r6155

 

[GenB]

Certainly did not pass the Visual examination either. In ASME Code you should certify it by virtue of a NonConformance Report. Of course your A.I. has to agree and sign off. Some one mentioned to amend the WPS but I think you cannot have that mishap in your quality system. Regards.

General Blr. CA,USA

 

[XL83NL]

Im with gtaw, supplemented with metengr's comment. What is the basis of rejecting, if the Code (albeit a minimum reuqirement) allows it and there are no further requirement from an engineering spec?

 

[r6155]

I assume the tension test was removed from a prolongation of the longitudinal joint.
Bend test was made ?... from the same test plate?

Regards
r6155

 

[gtaw]

I fail to see a problem. What is to say the original groove detail isn't as per the attached sketch? After all, the groove detail is a nonessential variable per Section IX.

Best regards - Al

 

[r6155]

The intention of nonessential variables is to reduce the number of welding procedure qualifications, not to correct mistakes of inspections during fabrication, or lack of inspections.

I think that other conflicts are in this pressure vessel, or not discovered yet.

Regards
r6155

 

[qcrobert]

May I offer a detail that came across my desk today of a 3/8" thk x 12' dia x 50' length vessel we will be fabricating this month.

Robert