UW 11(a)(5)(b) 2

[weldtek]

I'm interested in any comments you may have as to the interpretation of this paragraph.
Some folks I've talked with, say that in the case of a small pipe vessel where seamless pipe is used and both head seams total < 50 ft and were welded by the same welder, one spot is sufficient. I'm having difficulty in reconciling that practice with UW 52(4).

 

[TomBarsh]

I was looking at this last week. Hartford Inspection had that very example in their "Pressure Points" publication several years ago.

See

http://www.hsbglobalstandards.com/h...94d5d4c4c2285256d57005febc8/$FILE/PPNov00.pdf

See Page 2. They discuss the point about only only one "quality" shot required for both girth seams if performed by same welder and total length less than 50'.

 

[aclark]

TomBarsh: you are correct in the above case 1 spot is all that is required. Some manufactuers don't understand UW-11(a)(5)(b).You would not belive some of the answers I get when preforming a Joint Review.

 

[LSThill]

aclark (Mechanical)

Allen are you still using COMPRESS?

 

[JoeTank]

aclark,
A star for the understatement of the year about the dreaded UW-11(a)5(b)... so far.

Steve Braune
Tank Industry Consultants

http://www.tankindustry.com

 

[aclark]

Yes I still use compress mainly when checking calculations and whe teaching class.

 

[weldtek]

TomBarsh,
I went through a file I've kept of info pertaining to Code questions and came across the issue of Pressure Points I believe you referred to.
As always this question generates some interesting dialogue.
Let me bounce this off you guys,
It seems to me that the issue boils down to the selection of joint efficiency from Table UW 12, for a given joint. What I'm getting at is, if I say I need a E of 1 for head to shell seams but .85 for long seams, and apply UW 11(a)(5)(b) to those head to shell seams, then the head to shell seams are treated as their own increment(s) and I have to radiograph that increment(s) per UW 52. The rest of the vessel is comprised of a seperate increment(s) and is radiographed per UW 52.
Am I thinking about this correctly?

 

[metengr]

What I'm getting at is, if I say I need a E of 1 for head to shell seams but .85 for long seams, and apply UW 11(a)(5)(b) to those head to shell seams, then the head to shell seams are treated as their own increment(s) and I have to radiograph that increment(s) per UW 52. The rest of the vessel is comprised of a seperate increment(s) and is radiographed per UW 52.
Am I thinking about this correctly?

Yes

 

[codeeng]

As I remember this used to be call "Partial Radiography". One addition spot RT then you could apply E=1.