Full-Pen or multi-pass weld
Full-Pen or multi-pass weld
(OP)
Hi All,
I have a simple question that I'd like to get some opinions on. My firm is designing some heavy moment connections for industrial pipe racks that use end plates bolted to column flanges. The connection from the end plate to beam is typically a 5/16" max fillet weld. We have some locations where larger than 5/16" welds are required and start getting into multi-pass sizes. My supervisor is of the opinion that full-pen welds are more cost effective than a multi-pass (say 3/8" max 3-pass) welds. I just wanted to get some general opinions on this matter because to me that does not seem like a cost effective solution. Full-pen requires grinding and special inspection, a multi-pass welds required more weld metal but no inspection or grinding. Intuitively I would think a multi-pass filet would be the way to go but I could be wrong. Opinions?
Thanks,
Brad
I have a simple question that I'd like to get some opinions on. My firm is designing some heavy moment connections for industrial pipe racks that use end plates bolted to column flanges. The connection from the end plate to beam is typically a 5/16" max fillet weld. We have some locations where larger than 5/16" welds are required and start getting into multi-pass sizes. My supervisor is of the opinion that full-pen welds are more cost effective than a multi-pass (say 3/8" max 3-pass) welds. I just wanted to get some general opinions on this matter because to me that does not seem like a cost effective solution. Full-pen requires grinding and special inspection, a multi-pass welds required more weld metal but no inspection or grinding. Intuitively I would think a multi-pass filet would be the way to go but I could be wrong. Opinions?
Thanks,
Brad





RE: Full-Pen or multi-pass weld
Best regards - Al
RE: Full-Pen or multi-pass weld
Step 1, make sure you are speaking the same language.
Yes, there may be grinding involved. But grinding is generally done by a helper, at helper rates, while welding is done by welders, at welder rates.
RE: Full-Pen or multi-pass weld
http://www.modernsteel.com/Uploads/Issues/January_...
http://www.modernsteel.com/Uploads/Issues/May_2008...
RE: Full-Pen or multi-pass weld
If you have a root pass and 2 cover passes for a large weld, the chances of screwing up all three welds at the same point is just about 0.
If you have one very difficult weld made with just one pass to fill that much weld metal correctly, the chances of a complete weld with no failures at all is about 0. What is your penalty for failure?
RE: Full-Pen or multi-pass weld
In some cases it is simply easier to make the fillet weld bigger than it is to prepare the base metal for a CJP and either use a backing or double sided groove with a back gouge operation to ensure the weld is sound.
Best regards - Al
RE: Full-Pen or multi-pass weld
Brad