PQR qualification

[Jusplayn31]

We are qualifying a WPS to 1104 on 16" pipe 1" WT, the root was identified as exceeding the 1/16" root penetration, the welder used a nose rock to grind the 1/2" long area that exceeded the 1/16" allowance, is it acceptable to perform grinding on the root?

 

[DekDee]

Jusplayn31,
Can you please advise where the 1/16" allowance comes from ?
I have searched API 1104 and the only criteria I can find is 13.8.4 but that falls in Section 13 which is Automatic Welding without filler metal additions ??? Is that applicable to your situation ?

When qualifying a WPS/PQR the size of isolated excess reinforcement (both internal & external) is not considered critical because in most cases the reinforcement is removed and is not part of the test.
If you have widespread or total excess reinforcement on the root you have issues that need addressing ( possibly excess root gap, possibly insufficient root landing) and the WPS needs revision.

If you have isolated excess penetration then it is probably a welder issue and not a WPS issue.

In answer to your question:
IMHO - if it is WPS qualification there is no problem with grinding the excess internal penetration.
IMHO - if it is Welder Qualification you are not allowed to touch the excess internal penetration.

Regards,
DD

 

[SectionIX]

My thinking is that he is referring to API 1104 Clause 7.8.2 that mentions that the reinforcement SHOULD not be raised above the parent metal by 1/16". Although the external reinforcement can't be below the pipe surface, the 1/16" reinforment is a recommended practice and not a requirement

Not sure why that was performed as this was done for a PQR and the specimens would have been ground anyway.

 

[Jusplayn31]

Thanks for the info. The WPS we are qualifying is on 1"WT X65 grade pipe, the client has finally accepted the coupon but requested that we write an NCR to prevent this issue from happening again. I have tried to say that in order to write a nonconformance there must be a nonfulfillment of a requirement (specification, code or written requirement) this nutty French welding engineer will not let it rest because he doesn't want to admit he was wrong. I have tried explaining to him that grinding a root pass approximately 1/2" area cannot change the mechanical test results due to the way the samples are prepared. Hell the lab will machine a lot more than the little bit that was removed by grinding.

 

[DekDee]

Section IX,
Section 7.8.2 is titled Filler and Finish beads - this section is related to the capping run on the exterior of the pipe, nothing to do with root runs.

Jusplayn31,
Politely ask your French welding engineer to assist you with compiling your NCR - what is the basis for the NCR ?
Good luck,
DD

 

[SectionIX]

DekDee,

Fully aware of this as I am a contributer to this specification.

 

[Jusplayn31]

Thanks to everyone who has commented, got an e-mail today that said we are qualifying the PQR to 1104 but for the Acceptance criteria is B31.1 severe cyclic.. Ha Ha, so now I am back to the code book, so far I still can't find anything that specifically states the root cannot be touched during the qualification process. Any B31.3 experts out there??
My initial thought is that the qualifying spec should govern the WPS qualification and the NDE acceptance for grading the weld would be to the more stringent B31.1 acceptance criteria.,.,?

 

[DekDee]

Sounds like you have big problems as your client clearly does not know what they are doing.
You mention B31.1 twice and B31.3 once (as well as Severe Cyclic) - is this your typing error or more confusion from the client ?
Just to assist a little - Acceptance Criteria for maximum internal protusion (reinforcement) on 1" (25 mm) WT in accordance with B31.3 Severe Cyclic is less than or equal to 4 mm.
Cheers,
DD

 

[Jusplayn31]

DekDee ,sorry for the typo and yes it is B31.3 severe cyclic. So basically we are OK on what the welder done by grinding a spot in the root pass. The pipe in question is used for subsea oil and gas production so that is the reason for the more stringent acceptance for NDE examination. As of now the coupon is accepted and at the lab for mechanicals(the true test), the only battle left is not to write an NCR on something that is acceptable. I will keep you posted. Thanks again.

 

[wegm]

Jusplayn31,
Regarding the whole welding, there is no reason to perform grinding neither on the root nor on the cap since the dimensions on the sketch of the "sample procedure specification form" are for example only as clarified by the form's note. Regarding the excess reinforcements of the test specimens, for the tensile and nick-break tests the API 1104 recommendation is no grinding whereas the grinding is mandatory for the bend tests specimens. Please have a look at this link:

http://www.weldinguide.com/gdanastasiadis/viewtopic.php?f=24&t=440

regards
wegm