Forum 
Riveted tank repair - Thursday, March 04, 2010 - Ed Marston [781]
Does anyone know how API feels about welding repairs to riveted tanks. Specifically seal welding of rivets and the lap joints.
Re: Riveted tank repair - Thursday, March 04, 2010 - BABRTs [53]
API has no feelings either way. Most repair contractors have procedures for welding up the rivets. I have the contractor use the smallest rod as the lowest heat to seal the weld. On verts I have the rivets seal welded one foot above the floor and six rivets either side of any butt welded vert.on the horizontal.
Seal welding all the rivets is cost prohibitive.
Re: Riveted tank repair - Friday, March 05, 2010 - Ed Marston [781]Thank you.
Re: Riveted tank repair - Friday, March 05, 2010 - CNT [492]
Often the procedure will also call for a rivet to be seal welded in stages. Maybe one half the circumference will be sealed and then the welder moves to another rivet to seall half of its circumference and so on, and then back to the first rivet after it has cooled. The problem is, as you may know, that the heat causes the steel to move and loosens the rivets, so you end up sealing one rivet and usually causing another to weep. The idea is to get them sealed with the least amount of heat possible.
Also, Im pretty sure that API does not give you any more credit for joint efficiency if the rivets are seal welded.
