Piping Porosity

[holdpt]

I would like some other interpretations for Table 6.1 (8) if anyone has time. Does the "sum of piping porosity" mean the adding of each individual pin-hole or the length of the worm-hole or a combination? It would seem strange to accept a worm-hole spot that is at least 1/32 round and travels 1/4 of an inch. Also, it would be incredibly amazing to have a single spot of porosity that is between 1/4 and 3/8 inch in size that is only recognized as a discontinuity and not a defect. (I have seen some big ones in the past)

 

[Duwe6]

In D1.1 SUM = total of diameters.

"Don't worry about it" -- there are tens of thousands of major buildings built using this criteria. If it caused a problem, we would have known about it at least 40 years ago. There is a MASSIVE ammount of experience codified in D1.1.

IMHO, the reason that porosity - piping or shallow - is not a major defect is that it is round, giving no stress-riser. Think of a dragster or a jet fighter. They are highly stressed structures, and have thousands and thousands of holes drilled into them to lighten the frame members. No cracking or other problems caused by all these holes due to the stress easily flowing past the round discontinuities.

 

[holdpt]

"Don't worry about it": Famous last words!

Thanks Duwe6. I understand and agree with your opinion. After all, it's common to stop a crack with a circle. Initially it seemed as though it conflicted with other code mandated weld profile issues like sizes and terminations. Another reason I questioned it is because in 4.9.1.2 porosity is not even mentioned which I assumed meant that it has 0 tolerance. If that assumption is true, I couldn't wrap my head around why it is tolerated in production but not in testing.