Joint Designation F12 and Base material thickness

By BRI7070 Date 11-10-2017 21:20

Good Day Everybody,

I am helping a friend with some prequalified WPS's and I find that the F12 joint designation has the thickness in mm and not inches. I looked at the published eratta with AWS and the T1 and T2 thickness was not changed.There were some changes about mm to inches but not the T1 and T2.

So I converted the 3mm to 0.118", close enough to call it 1/8". Well looking at TC-F12-GF the T1 or T2 is <3 and the TC-F12a-GF is equal to or >3.
Well I got to thinking and <3 is less then 1/8" that does not seem right. I then look at the F12 Joint designation in mm and the T1 or T2 is 75mm which is 2.95".

So does anybody have an answer as to what the T1 or T2 thickness should be in inches?

P.S. I did not find the answer using the search option.

By Steelslinger (**)

Date 11-10-2017 21:52 Edited 11-10-2017 22:04

3 inch

Note 'b' on refers you to 5.22.1 which corrected with the Errata goes to:

5.21.1 "Fillet Weld Assembly" Will shed some light on it. Has to do with Max allowed root opening.

By BRI7070 Date 11-10-2017 22:11

Well darn, After talking with another inspector and reading the fillet weld assy tolerances in the joint design and going to that paragraph I had realized that 3" is correct. Just not used to seeing such a large dimension in joint designations.

Thanks for your input!!!!