Maximum root opening Pre- qualified TCU-4a-GF and TCU-4b-GF

By rich allen Date 02-04-2009 15:48 Edited 02-04-2009 15:54

Good morning all,

Shop errors have resulted to over-sized root openings of CP welds in the field. We have submitted Pre- Qual. WPS using different joints but the ones that specifically deal with this issue are TCU-4a-GF and 4b-GF.
The root openings vary from 1/4" - 1"
All joints are utilizing a backup bar. The process is FCAW and the wire is Lincoln NR-232.
Do I need to write another WPS for the larger root openings? 3.11.3 Root Openings only talks about automatic or machine requiring additional paperwork.
The mmaterial being welded is WF beams with flanges that vary in thickness from 3/8"-1/2"

Any help is greatly appreciated.

Rich

By ctacker (****)

Date 02-04-2009 16:09

I think you need to look at 3.13, particularly 3.13.1, and at the tolerances of figure 3.4. if you have a 1" root opening you wouldn't be able to use a prequalified WPS. without having the as detailed, and knowing the groove angle detailed, you cant get a firm answer on what the limit would be for a PWPS.

By jwright650 (*****)

Date 02-04-2009 16:10

Rich I can help ya on some of these but the 1" stuff may need another angle of attack. (See AWS D1.1 Paragraph 5.22.4.3 and C5.22.4.3) Be advised that the EOR needs to approve this.

By rich allen Date 02-04-2009 18:34 Edited 02-04-2009 18:38

Thank you guys for the replies.

The groove angle listed on our procedure 45.
I don't mind writing a new procedure for the largest root of 1"......... I just need to know if it's required and what the inspection company will expect from the new procedure.
I'm attaching a copy of the procedure we used.

Thank you,

Rich

Attachment: WPS30-07TC-U4a-GFNR232.doc (51k)

By jwright650 (*****)

Date 02-04-2009 18:42

The paragraphs that I listed above talk about buttering both sides of the joint so that you are back within your prequal WPS tolerance.

By ctacker (****)

Date 02-04-2009 22:40

Would be hard to butter both sides given the joint detail :)
And you would need to get EOR approval first.
My question would be, would that still fall under prequalified with engineer approval, or would you need to need to run a test plate?

By ctacker (****)

Date 02-04-2009 22:45

Why does your base material thickness range list group1 or group 2? shouldn't that show 1/8" to unlimited.
and for filler metal thickness groove, should'nt it show the thickness of filler metal deposited ?

By DAYANARA (**)

Date 02-08-2009 21:23

Dear

You shall write other WPS, because the root opening is ouside the maximum aceptable for prequalified WPS.
The maximum root opening for joint is 1/4"+1/4 = 1/2".
Please review also 5.22.4.1 (figure 5.3), more tolerance shall be approval for engineer.

Other:
1.- WPS thickness range is wrong, change for 1/8" to unlimited.
2.- Is possible weld with 240-256A for all position?.

Dayanara