Maximum thickness for lap welds- API-650

[JStephen]

I thought there was a 3/8" limitation on lap-welded bottom thickness in API-650, but I can't seem to find any limitation in the standard. Am I overlooking it, or are you really allowed to lap weld a 1.5" bottom if you so desire?

 

[rab1944]

OK I'll bite.
I found nothing in API 650 either, but obviously you would need a bw annular plate. The breakdown would be impractical past 3/8" and the three plate laps would be a challenge for an earthling. I also checked Euronorm and found nothing. AWWA D100-05, however, Section5.9.4.5 states "Bottom plates under the sidewall that are thicker than 3/8" shall be butt welded.

Great question.