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Crown surface above base metal by more than 1.6 mm

Crown surface above base metal by more than 1.6 mm

Postby zirsald » Mon Oct 28, 2013 3:22 pm

Dear members,
Please note that I have prepared a PQR test specimen as per API 1104 using 14" API 5L X52 pipe with thickness 12.7 mm and after the completion of the welding and during visual inspection I have measured the crown surface which is raised above the parent metal by 2 mm and thus above the maximum limit (1.6 mm) that specified in section 7.8.2 of API 1104. Could you please let me know if the PQR is considered to have failed or it has to do only with welder's qualification?
Thanks
zirsald
 
Posts: 14
Joined: Mon Sep 30, 2013 1:51 pm

Re: Crown surface above base metal by more than 1.6 mm

Postby Ballbearing » Mon Oct 28, 2013 9:40 pm

Zirsald,
Section 7 is related to Production welding and it lists the requirements for acceptable production welds.
However, the requirement for 1.6 mm maximum reinforcement is prefixed with a should (recommended practice) and not a shall (mandatory) - see 3.2.18.
Hope that helps,
Cheers,
BB
Ballbearing
 
Posts: 76
Joined: Wed Jun 12, 2013 10:11 pm

Re: Crown surface above base metal by more than 1.6 mm

Postby zirsald » Tue Oct 29, 2013 1:19 pm

Ballbearing,
Thank you for your reply. Though I agree with you that the section 7 is related to the production welding, the "Standard V-Bevel Butt Joint" sketch of Figure 1 (sample procedure specification form) of section 5 shows that the excess cap reinforcement shall not be more that 1.6 mm. Could you please let me have your opinion and kindly advise if you think that the excess reinforcement shall be removed by grinding in order for test specimen to be in compliance with that sketch.
Thanks
zirsald
 
Posts: 14
Joined: Mon Sep 30, 2013 1:51 pm

Re: Crown surface above base metal by more than 1.6 mm

Postby mawsamit » Tue Oct 29, 2013 7:34 pm

Zirsald,
Please have a look to the "Note" of the sketch that you have mentioned that clearly states: "Dimensions are for example only". So, the cap excess reinforcement to be maximum 1.6 mm is a recommended practice and not a mandatory rule as clarified by Ballbearing. Regarding performance of grinding or not, please note that it is addressed by the code since for the tensile-strength and nick-break test specimens the Figures 4 and 5 of section 5 specify that the weld reinforcement should not be removed on either side of specimen and with regard to the root-, face- and side-bend test specimens the Figures 6 and 7 of section 5 specify that the weld reinforcement shall be removed from both faces flush with the surface of the specimen. So, for the tensile and nick-break tests the API 1104 code recommends (should) you leave the excess reinforcements as they are and although you could remove them I strongly believe that at your case there is no reason for such a removal. Instead, for the bend tests the code imposes (shall) the removal of excess reinforcements and thus you are obliged to do it.
mawsamit
 
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Joined: Thu Oct 24, 2013 11:16 am


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