Columns made of shape rolled plates in splices

By Dualie

Date 07-16-2014 04:54

depends on the shape and desired weld groove

By Leonardo Martínez (*)

Date 07-18-2014 16:19

Please see the two web images and my new explanation, the weld is CJP.

By welderbrent (*****)

Date 07-16-2014 05:01

The codes don't recommend shop practice or procedure. If you have to ask you may be in over your head.

As to the second question...???

He Is In Control, Have a Great Day, Brent

By SCOTTN

Date 07-16-2014 13:19

I'm also unsure about the 2nd question. Are any of the plates for these built up columns thicker than 2"?

By Leonardo Martínez (*)

Date 07-18-2014 16:21

Is 1/2" thk the shell

By ssbn727 (*****)

Date 07-18-2014 08:41

Got drawing? Maybe can help... No Drawing? No help! :smile:

Seriously, a picture is worth a thousand words so if you have a visual representation available to post then maybe we can get somewhere okay?

Respectfully,
Henry

By Leonardo Martínez (*)

Date 07-18-2014 12:29

Ok, you´re right. Please explain me How insert a figure here?

By Leonardo Martínez (*)

Date 07-18-2014 16:18

http://www.cianco.com/catalogos/img_producto/gr_20101001120950_CCA2gr.jpg http://ceacsa.e.telefonica.net/CILINDRADO%20VIROLAS%20Y%20CONOS/CATALOGO%20002-1.jpg

This image is not the case but its look like, imagine that is not a cover, that is a rolled shape pieces (shells) joint one anoter by circunferential welds, and each shell is made in a machine by rolling a plate, so each shell made it have a longitudinal weld.

I fits one shell to another, so I will create the column piece by circunferential joints, the real inquiry is: what says the structural codes about the orientation of the longitudinal welds of each couple of shells joined, can it be aligned? should be misaligned, there is a structural reason for?. What recommends the codes or experts when the columns is made of 2 shells? 3 shells? etc.

I don´t know if my new explanation helps, but if don`t, tell me and I can try to search other way to show it.

thanks.

By SCOTTN

Date 07-18-2014 16:33

I don't recall D1.1 stipulating the orientation of the longitudinal welds. It looks like they're all in line in the first photo. I would think that they could be aligned or misaligned, though, that may be something to address with the EOR. If that's the weld seam I see in the first photo, I think that the column would look better with the weld seam in line as opposed to misaligned.

By welderbrent (*****)

Date 07-18-2014 16:55

Don't think the codes are going to answer that. More of an eye appeal and/or engineering issue.

The structural integrity will be influenced by the joint used to accomplish the welding, any bond between the multiple layers of the column in both the circumferential and longitudinal welds, and the quality of each individual weld.

He Is In Control, Have a Great Day, Brent

By Joey

Date 07-21-2014 03:47

I fits one shell to another, so I will create the column piece by circunferential joints, the real inquiry is: what says the structural codes about the orientation of the longitudinal welds of each couple of shells joined, can it be aligned? should be misaligned, there is a structural reason for?. What recommends the codes or experts when the columns is made of 2 shells? 3 shells? etc.

The position of longitudinal welds should be specified in the construction drawing or shop drawing. I have not seen two longitudinal welds alligned when joining by circumferential welding. If it is a tank construction, the vertical welds on shell courses shall not be aligned but shall be offset from each other a minimum distance of 5t, where t is the plate thickness of the thicker.

You best bet is to ask the Engineer. The weld orientation should be in the drawing. I don't think it's a good engineering decision to align them :eek:

By JTMcC

Date 07-21-2014 19:39

I don't recall any code references to this, but have always (usually demanded by spec or onsite supervision) seen the seams staggered in both pressure piping (mainline construction) and structural cans, caissons, pipe pile, drilled hole liner (whatever the specs call it on that particular day).
Specification by experienced engineering in that field normally calls for offset of longitudinal pipe seams of at least 20%.

The usual purported reason being to prevent an unzipping failure in the event of a single longitudinal seam letting go under load. Hydro tests for this in mainline work, in structural work it's really untestable and assumed.

But no I've never seen a spec that called for aligning longitudinal pipe/welded rolled plate seams in alignment. Just the opposite.

I've seen a couple of hundred pipe failures under hydro, and have the pictures, none of them have traveled across a welded joint, but staggering is still the common practice (demand) in my bit of experience.

Confirm with the engineer, but staggered is the industry norm.

J