Joint efficiency for UT in lieu of RT

[ArnoldoGarcia]

I want to ask for help for interpretation of the next situation.
In a reactor designed by ASME code Section VIII Div 1, Ed 2015, I want to apply 100% UT in lieu of 100% RT as per paragraph UW-51 (4). But in the table UW-12 of joint efficiences, it says that apply only for % of Radiographic examination,

If I use 100% UT, the joint efficiency is still 1.0? Where can I find the relation between UT and Joint efficiency?

The ASME code does not states clear this situation.

Thank you in advance for your help.

Best regards,
Arnoldo G.

 

[TGS4]

Clarify it with your AI. You are applying UT in lieu of RT, so anywhere that you see RT, replace with UT.

 

[dhengr]

ArnoldoGarcia:
The method of testing depends to a great extent what kind of defects you intend to find and reveal and to the orientation of the joints and areas you are testing, and to your confidence in each method and the person interpreting the test results. Otherwise, some of you guys know the ASME PV codes and their idiosyncracies much better than I do. They do not always lend themselves to a straight forward understanding of why one thing is favored over another.

 

[ArnoldoGarcia]

More information about my case:
The reactors we design are so big, and allays we consider 100%RT examination in order to reduce the thickness of the plates.
But the time to examine all the joints is long and this is the reason we want to use UT (Phased array) in lieu of RT.
But again...Which is the relation between UT (Phased Array) and the Joint Efficiencies?
Thanks a lot.

 

[TGS4]

Provided that UT is in compliance with UW-51(a)(4), then you can substitute UT extent for RT extent in UW-12 to determine your appropriate weld joint efficiency factor.

As I said before, you can clarify/confirm this with your AI.

 

[chaulklate]

I believe the answer lies in the original Code Case 2235-9. It stipulates minimum 1/2" (13mm) thickness and then a list of complimentary requirements. Whether or not that Code Case was struck and written into the Code, I am not sure.

 

[TGS4]

chaulklate - the current revision for Code Case 2235 is -13 (dated July 9, 2014). Between Revision 12 and Revision 13, Section VIII Divisions 1 and 2 were dropped from the scope, because it was incorporated into the Code: Division 2 in 7.5.5, and Division 1 in UW-51(a)(4) - which refers to Division 2.

 

[ArnoldoGarcia]

Thanks to all of you for your replies.
I understand that in my case, the use of UT is under the AI approbation, because the ASME code is not complete clear and is
an interpretation issue.

Regards,
Arnoldo G.

 

[TGS4]

ArnoldoGarcia - in my opinion the Code is completely clear. Provided that UT is in compliance with UW-51(a)(4), then you can substitute UT extent for RT extent in UW-12 to determine your appropriate weld joint efficiency factor.

If you do not think that this is sufficiently clear, then you are welcome to submit an Interpretation Request directly to the Code Committee itself -

http://go.asme.org/InterpretationRequest

 

[ArnoldoGarcia]

TGS4 - Thank you for your answer, I got your point.
I will submit the Interpretation Request.
Regards

 

[TGS4]

Please advise of the tracking number provided to you by ASME.

 

[bpv66]

ArnoldoGarcia,

Check out Interpretation VIII-1-15-19. It permits using UT in lieu of RT when performing spot examinations per UW-52. This would allow you to use 85% Joint Efficiency. I think you will get the same sort of answer when you submit your joint efficiency interpretation as described above.

Also, keep in mind that Code Case 2235 required "UT" to be stamped on the vessel nameplate when using UT in lieu of RT. This requirement was not incorporated into Section VIII. Therefore, you are required to stamp the nameplate in accordance with UG-116(e) with RT-1, RT-2, RT-3 or RT-4 depending on degree of examination. I would suggest you include in the Remarks section of the U Form that UT was performed in lieu of RT in accordance with 7.5.5 of ASME Section VIII, Div. 2.

Standard Designation: BPV Section VIII Div 1
Edition/Addenda: 2013
Para./Fig./Table No: UW-52
Subject Description: Section VIII, Division 1; UW-52 - Spot Examination of Welded Joints
Date Issued: 12/29/2014
Record Number: 14-794
Interpretation Number : VIII-1-15-19

Question(s) and Reply(ies): Question: May an ultrasonic examination method, performed in accordance with ASME Section VIII, Div. 2 Paragraph 7.5.5, be used to perform spot examinations of welded joints in accordance with ASME Section VIII, Div. 1 Paragraph UW-52?

Reply: Yes.

 

[ArnoldoGarcia]

TGS4. I already request the interpretation to ASME and I received an email with the request no is 16-1622.

 

[ArnoldoGarcia]

bpv66,
thank you for your reply. Personally I also believe that the efficiency shall be the same using either RT or UT.

Best Regards,
Arnoldo G.

 

[Mech2325]

ArnoldoGarcia: Please send me the link where the your mentioned request number be entered. I found zero results for this request number

 

[TGS4]

A duplicate request under number 16-1607 was also filed. The item will be carried forward under this number: 16-1607.

 

[ArnoldoGarcia]

TGS4: Where can I verify if the request 16-1607 has been answered?

Thanks you
Regards,
Arnoldo Garcia

 

[jte]

ArnoldoGarcia-

The next meeting will be in a few weeks. If you attend, your item is more likely to be discussed.

https://cstools.asme.org/csconnect/FileUpload.cfm?View=yes&ID=28314

 

[TGS4]

The item is active and under consideration. I would take up jte on his suggestion.