API 620 - stainless to plain carbon shell plates

[andyross333]

Does anyone have information about welding stainless steel shell plates to plain carbon shell plates? Our client would prefer to lap weld along the horizontal seams. Is this permitted per API 620?

Thanks.

 

[Duwe6]

There is a major joint efficiency penalty for lap welds. It take good tank welders to make full-penn welds; any pathetic welder can do lap welds [including me, and i am pathetic]. If the customer can't find good welders, round some up for them. A good tank with stainless in the high corrosion areas should last into the next century. Don't use laps; get good welders and make good, full-strength welds.