Tank shell weld prcedure? Options

[Lincolnhill]

Hi all, question for the tank bashers,
Whats the common weld procedure for storage tank shells? Does it vary much or is there a specific procedure in API 650?
Just heard (in a pub chat) of a crowd doing work near us back gouging so im curious are they doing a prep on one side,building there tank, welding and back gouging or whats the story/reason with this?
Ive done storage tank floor repairs in the past (annular plate replacemnet, roof repairs) but never any shell work so im purely curious 🤔

[welderteacher]

We have ran lots tank tests. The test is usually a 15mm T Butt rooted with cellulosic fill and cap P48 (7018)
Reverse is back ground (procedure allows gouging) then filled with P48. This was to ISO 9606 and ASME X1.

This post has been edited by welderteacher: Sep 10 2020, 12:07 PM

[Lincolnhill]

Thanks for that, is the test normally prepped from one side? Root gap used aswell?

[welderteacher]

Yeah prepped one side, no root gap cellulosic root vert down/horizontal.

The procedure is to 15614-1


This post has been edited by welderteacher: Sep 25 2020, 12:19 PM

[Lincolnhill]

Cheers thanks for the info

[CChive68]

Every tank related standard ,I have seen ,calls for double sided welds, for the shell butts. This is regardless of material grade.