Mock ups for T,Y,K qualifications

By pcoloma Date 01-14-2009 02:59

Dear sirs: I need to qualify a procedure for T,Y,K connections according to AWS D1.1-2006. I plan to use prequalified joint details according to 3.13.4 ( table 3.6). Unfortunately, the contract does not allow prequalified WPSs..I need to qualify them.
Based on 4.12.4.1 I nedd to weld a coupon according to Fig 4.27 and to prepare a sample joint or tubular mock up...
Questions
1. I won´t change prequalified joint details.....Do I still need to perform the mock up test?
2. Is it possible to use plates for the preparation of the mock ups or sample joints? The geometries and welding position required seem to be fixed. So it should be possible to use plates to create coupons with the required geometric characteristics
3. Welding positions required at 4.12.4.1 82) are fixed: vertical, overhead, etc. How can I get fixed positions with tubular mock ups ( where the position changes around the pipe)
4. I don't understand condition 4.12.4.1 (2) (a)..it asks for one test ( gretest groove depth + smallest groove angle)or for several tests ( ...or combinations of grooves to be used)?

Does somebody have examples or past experiences preparing mock up tests to satisfy these code requirements?

By swnorris (****)

Date 01-14-2009 14:55

When working to D1.1, I've never heard of any prequalified WPS not being allowed. The joint dimensions and groove angles must exceed prequalified criteria.

By pcoloma Date 01-14-2009 15:54

Thanks for your answer.According to the contract I am working with, welding procedures shall be qualified by testing.

By Richard Cook (**)

Date 01-28-2009 21:09

In our industry, we commonly see this entered in the specifications, we usually RFI the section for clarification, in most instances the engineer allowed prequalified.

Remember job specs are thrown together by individuals that do not have the expertise on all matters. So questioning this issue with the engineer may get it changed. A lot of the time it is placed in the specs as a general statement and not reflecting the true intent of the provider. Do not be afraid to question it, it will save you head aches and money.

Argue the fact that the AWS "prequalified" WPS have been qualified over years of experiance (C-3.2.1), they have been proven and are "qualified" by the industry.

By pax23

Date 01-14-2009 20:28

It is not rare. Some industries and some well known companies out there will spec out D1.1 for welding but specifically disallow the use of prequalified WPSs in the contract documents. They want to see PQRs run by the contractor for all welding.

By kipman

Date 01-14-2009 16:53

Try looking at these threads - they provide some info.
http://www.aws.org/cgi-bin/mwf/topic_show.pl?pid=116096;hl=TKY
http://www.aws.org/cgi-bin/mwf/topic_show.pl?pid=113424;hl=TKY
http://www.aws.org/cgi-bin/mwf/topic_show.pl?pid=96954;hl=TYK

There are other threads in this forum dealing with TYKs. Try the search function. There may be enough already written to answer your questions.
Regards,
Mankenberg