Prequalified WPS

By Lawrence (*****)

Date 09-09-2008 17:36

Bert,

A dual process prequalified WPS can be made.

But be sure that the work is all prequalified.

You mention "root pass" and hot pass"..... Those terms bring to mind open root joints, which are not prequalified in plate unless they are back gouged.

If your root pass is back gouged or a backing strip is employed than you simply must meet the requirements provided in section 3.

By pipewelder_1999 (****)

Date 09-09-2008 20:46 Edited 09-10-2008 12:59

Just to add to Lawrence's information. You can also just use each WPS alone for part of the joint. One joint can be welded with 2 WPS's. Also for TYK connections, [EDIT]some [/Edit] joints welded from one side without backing are prequalified. Everything else is not.

By kipman

Date 09-10-2008 12:56

Gerald,
I feel that your post may be slightly misleading - only a few single-sided TYKs will actually meet prequalified criteria. The scope of Section 3 of D1.1 states that "in order for a WPS to be prequalified, conformance with all of the applicable requirements of Section 3 shall be required". Section 3 does not give prequalified status to any groove weld with an included groove angle of less than 30 degrees (ref Table 3.6 note b for example). What this effectively does is limit prequalified TKYs to only the simplest configurations (T-joints or Y-joints that are close to perpendicular, i.e. more than 60 degrees or so brace intersection angle).
Mankenberg

PS - you have e-mail.

By pipewelder_1999 (****)

Date 09-10-2008 13:55

I edited the text a little. I appreciate your time.

Gerald

By bert lee (**)

Date 09-10-2008 16:04 Edited 09-10-2008 16:10

Hi Lawrence & Kip

we made a prequailifed wps that combines two welding processes (SMAW & FCAW). all parameters, materials, electrodes etc are based on prequalified requirements.
All I wanted to know is if there is a clause in D1.1 that allows two processes in a single prequailified WPS.

How do you interpret below statement? TPI has rejected my single prequalified wps because of the two processes stated, he claimed that D1.1 never mentioned the prequalified for two processes in a single wps.

Combination of WPSs. A combination of qualified
and prequalified WPSs may be used without qualification
of the combination, provided the limitation of
essential variables applicable to each process is observed.

regards
Bert

By hogan

Date 09-10-2008 16:13

Bert,
One more thing to consider is if there are any seismic requirements, then sometimes you are required to test welds made by mixing processes. FYI

By aevald

Date 09-11-2008 04:00

Hello Bert, to add just a bit more to hogan's statement, some time ago there was a thread where there were discussions about mixing processes or different filler metals within the same process. In some instances the sequence of the application of a filler can be a cause for metallurgical issues. Prime example is using E6010 or E6011 electrode for the first weld pass applications and then following up with the use of E7018 filler. This combination is perfectly acceptable and used throughout the world on many applications, yet, if you reverse the order of the application for any reason, you can end up with some serious weld bead integrity problems. I believe there are some similar issues when you have an FCAW self-shielded filler and apply certain SMAW fillers on top of those. So you should certainly do some research and possibly some testing to verify that there aren't any conflicting process issues. Just my additional $.02 Best regards, aevald

By bert lee (**)

Date 09-11-2008 05:37

Thanks Hogan & aevald,

but if you will based alone on D1.1, will you accept two processes in a single prequalified wps?

Best Regards
Bert

By aevald

Date 09-11-2008 06:57

Hello Bert, I believe that D1.1 may not make that sort of distinction or allowance. What hogan mentioned referencing seismic requirements and I mentioned about mixing processes, are also possibly different issues. The seismic issue is often imposed upon structures that are within specific geographical areas and based upon sound construction practices for buildings in these seismically affected areas. They spell out additional requirements for welding filler metals and limit use and application of them. These requirements would be based on D1.1 and likely include some of the FEMA specifications that can be imposed as an additional requirement, but are not code or part of D1.1 directly. The mixing of process or fillers that I mentioned are based on some of the metallurgical issues that can arise from using multiple processes or fillers that might not be compatible with one another, thus you would likely want to verify this compatibility either through testing or existing verifiable information on the specific combinations or processes. I am sorry if this seems rather confusing, there are others on the forum here who might be able to condense and clarify this better for you. The information that hogan and I have included is likely not directly related to your original question, yet I do believe that it is something to consider since you have not detailed the application of this process or processes. Best regards, aevald

By kipman

Date 09-11-2008 13:53

D1.1 does not prohibit the practice of listing two practices on a single WPS, either prequalified or qualified. In fact, if you look at form N-1 in Annex N of D1.1 it clearly indicates that more than one process may be listed and it provides suitable space to record the essential variables of multiple processes. Note that Annex N is not mandatory, i.e. it is not mandatory to use this form - you can develop your own form to better suit your needs.
Mankenberg

By bert lee (**)

Date 09-11-2008 15:49

Dear aevald & Kip - I've got useful information from both of you. thank you Sir

Kip - i read many of your advises in welding journal in late 90s and hope to read more from you in this forum, especially, Inspection forum. to me, you are one of the best in this line. :=)

best regards

bert