UW 11(A)(5)(b) verse UW11 (b) 4

[charpyboy50]

|Per Section VIII Div 1. can anyone in laymens terms explain the difference between the two and when and when not to use them.

 

[metengr]

Review this thread;
thread794-174111

 

[CodeRef]

Try this link:

http://www.authorizedinspector.com/Joint Efficiencies.htm

There are three kinds of people in this world; those who can count and those who can't.

 

[Bobfromoh]

I'd like to put my 2 cents worth in on this subject.
Properly applying UW 11(A)(5)(b) allows the use of a 1.0 weld efficency in the head and shell. The long welds must be 100% radiographed or a seamless shell used. Each vessel must be radiographed.

Paragraph UW 11(b)[RT3] is for spot radiograph and the one spot on 50 feet of weld applies. A joint efficency of 0.85 is used for the shell and head. This may result in a lot less inspection for a UW 11(b) vessel.

I am presently working on a project that requires radiograph per UW 11(A)(5)(b). Nobody is sure why it is required so I asked an AI if he knew why it would be specified? He said he wasn't sure other than the fact that he rarely sees RT2 [UW 11(A)(5)(b)] specified any more. It's usually full radiograph (RT1) or spot (RT3).

Also, since the ASME Code is difficult to interpret, the pictures that CodeJackel references are relied on more to specify radiograph requirements.

Hope this helps?

 

[CodeRef]

I want to add this......With regards to the RT stamping requirements of RT-1,2,3 and 4 stated in UG-116, you have to remember that the radiography used to satisfy paragraph UW-11(a)(5)(b) cannot be used to satisfy other weld increments that have spot radiography rules applied to them.
In short, paragraph UW-11(a)(5)(b) radiography MUST be separate shots and do not contribute to the UG-116, RT-1,2,3 and 4 rules for stamping.

The UW-11(a)(5)(b) RT shot is used as a "QUALITY" shot or in another term, a statistical “quality check” of the
ability of the welder to deposit sound weld metal. One reason for the quality shot is because the stresses acting on the Category B welds (circumfirential) do not control the design for an internal pressure only load case.


There are three kinds of people in this world; those who can count and those who can't.

 

[weldtek]

CodeJackal
'In short, paragraph UW-11(a)(5)(b) radiography MUST be separate shots and do not contribute to the UG-116, RT-1,2,3 and 4 rules for stamping.'
This coment may be confusing. The radiographs taken per UW11(a)(5)(b) do indeed influence the appropriate stamping.
As an example the spot radiographs on round seams when combined with the complete radiography applied to long seams result in RT-2, as the spots taken on long seams when combined with spots on round seams taken per UW11(a)(5)(b) can result in RT-4.

 

[weldtek]

For more discussion on this topic, see thread in ASME Mechanical Code Issues # 292-154335

 

[CodeRef]

Yes, you are correct in that statement regarding RT-2. It does indeed influence the appropriate stamping as you indicated. I just wanted to make it clear that "quality shots" as I described should not be used to satisfy other weld increments and I stand corrected. Thanks weldtek.

There are three kinds of people in this world; those who can count and those who can't.

 

[JoeTank]

CharpyBoy50,
To answer your original question... No, it can't be explained in simple terms.

Joe Tank

 

[SnTMan]

JoeTank, a star for you.