determining joint efficiencies

[cookdog]

Is there a simplified version or wording of UW-11, in ASME SECTION 8, Div. 1?

thanks

 

[LSThill]

Hi cookdog (Chemical)

UW-12 JOINT EFFICIENCIES
thread292-40534

Leonard@thill.biz

http://www.thill.biz

 

[PVRV]

1) Double-Welded Butt Joint (Type 1)
E
1.1 Full RT --> 100%
1.2 Spot RT --> 85%
1.3 No RT --> 70%

2) Single-Welded Butt-Joint (Type 2)
(Backing Strip in place)
2.1 Full RT --> 90%
2.2 Spot RT --> 80%
2.3 No RT --> 65%

3) Single-Welded Butt-Joint (Type 3)

3.1 No RT --> 60%


Note, equivalent welds to item 1.1 above include Single-Welded Butt-Joint back chipped and welded from the inside;
those may have 100% joint efficiency.

Weld Categories A, B, C, D (UW-3)

A --> Longitudinal Seams
B --> Circumfrential Seams
C --> Terminal Weld end in a flange
D --> Attachments

Type of Radiography

RT-1 --> Full lenght, full radiography of a;; butt welds
(except >= NPS 10 or tn >= 1 1/8"

RT-2 --> Cat-A: Full Lenght
Cat-B: T-joints

RT-3 --> Spot Radiography (UW-52)

RT-4 --> Partial / No Radiography

Seamless Heads & Vessel Sections --> 100%
Piping SAW & Seamless --> 100% ERW --> 85%

 

[Rerate]

Q: Is there a simplified....

A: No. The best summary I know of is in the Pressure Vessel Handbook, Megyesy, part I section 7, welding of pressure vessels. This goes into what they mean by "types" and "category" and levels of x-ray. Then charts and tables tell you joint efficiency for various combinations of the above.

Please don't take this the wrong way. I do not know you, your problem or your background. And I am new to this forum. I strongly recommend you talk to a specialist about this as there are many considerations to joint efficiency.

 

[ume153]

Hi

go to PVeng.com and download the spreadsheet which give the data available in Megyeseys book in softform.

 

[deanc]

Follow the advice of Isthill and look at the thread. You will get bad info. surfing around. Remember you must submitt calcs.to your AIA.

 

[LSThill]

Hi cookdog (Chemical)

I agree with deanc (Specifier/Regul) ask the AIA.

Leonard Stephen Thill
Leonard@thill.biz

http://www.thill.biz

 

[PVRV]

Very interesting thread.

thanx isthill & deanc

 

[LSThill]

HI cookdog (Chemical)

Also, Nooter Fabricators, Inc Quick reference Guide ASME PRESSURE VESSEL CODE (SECTION VIII, DIV. 1. Has all Testing Notes & Reference Notes.

The software program was free.

Leonard@thill.biz

http://www.thill.biz

 

[kyong]

I would recommend to see Flow Chart Diagram in Appendix of ASME Section VIII Div 1. I have not felt any difficulty to determine joint efficiency since I that flow chart. I made a summarized excel spread sheet, but this is only for me because it is customized for my own use.