Socket Weld Interpretation 1

[mudd41]

B31.3 states that non-fusion is not allowed in the weld. My question is, if you are X-Raying a socket weld for gap and find that the weld has non-fusion, does this become a weld quality item that should be repaired accordingly?

 

[QC1971]

I think that you will find that ASME does not establish an acceptance criteria for NDE results that are not mandated by code, it is a matter of agreement between the owner and fabricator.

 

[Mr168]

Agree with QC1971. If the RT criteria is that socket weld gap is greater than or equal to X, there is no Code basis to reject it based on LOF, porosity, etc, if it met all other visual and NDE requirements.

What informational RT's do, if they land in the client's hands (or the client catches wind), is give them firepower and cause behind further investigation. Sometimes it's simply an isolated bad weld, other times, it's a portal into a world of gross negligence and nonconformances by a vendor. As such, it's typically handled on a case-by-case basis.

 

[mudd41]

Very helpful and exactly what I was thinking so I would like to thank both you Mr168 and QC1971.

 

[Kiwi2671]

mudd41,
B31.3 Table 341.3.2 lists examination methods for LOF as Visual and Radiography.
NFS and Severe Cyclic state that LOF for Fillet Welds (which includes socket welds as per Note 4) is an A ( zero imperfection allowed).

However, internal slag, internal tungsten inclusion, internal porosity are all listed as N/A for fillet welds.

IMHO the intention of the code is LOF identified by visual inspection on fillet welds is not acceptable but this does not apply to radiography.
Could certainly cause confusion and some wrongly rejected welds,
Regards,
Kiwi

 

[Duwe6]

Engineering hat on: Lack-of-Fusion degrades the pressure boundary strength of the fillet weld. This is bad. ASME B31.3 has NO allowance for L.F. [i.e. even the tiniest ammount is Rejectable and requires repair]. It has been detected. Fix it.
Now check the welder's ID stamp on that weld and X-ray some more of his work, until you are reasonably assured that you found all of his mistakes. Fix all L.F. areas found.

Legal hat on: You are now indisputably aware of a significant defect in the structural integrety -- bending stress between pipe supports, and pressure-boundary integrety of work you are responsible for. You have assumed any and all liability, plus consequentiol damages like Loss of Income due to having a $50K/hour Unit shut down. This problem has become 'your baby'. Fix it.
Now cease all X-ray-for-Gap so no more defects will be found, since X-ray-for-Gap is not a Code requirement.