Difference between Spot and Partial RT weld inspection 1

[jberens]

I'm doing a calculation for a pressure vessel that was built back in 1980. I can't confirm the original MAWP and I think it has to do with the joint efficiency. For the Girth weld inspection, the U-1A form lists a Partial weld inspection. One of my collegues thought that partial inspections were removed from the code around 1985. What is the definition of a Partial weld inspection? Is it greater than or equal to a spot inspection? TIA

 

[vesselfab]

it's a spot of sorts

normally, the T-joints in Circumferential seams were spot radiographed and graded to full RT quality.

This yielded a 1.00 (100%) JE

look in UW-11(a)(5)(b)

these spots were over and above and of the 1 shot in 50 ft for any other spot RT.

 

[jberens]

that was the section of the code I was looking at, I just needed to know if I could consider the Partial RT equal to or greater than the Spot weld.

 

[vesselfab]

doesn't your U-1a list a 100% je for girth seams?

 

[jberens]

no, it doesn't list an efficiency for the Girth seams, only the long seams

 

[vesselfab]

hmm. guess I have forgotten they didn't show that back then.

but anyway, that's what the partial was. Worded a little differently as I remember, in essentially the same as now.

did it check out ok with 1.0 je?

 

[jberens]

yes, that's how we believe they did the original calc. We're just trying to justify it. The form list Spot, Partial, Full in that order. I hate to assume partial fell somewhere between spot and full, but that's how it looks.

 

[CodeRef]

After reading what the 1977 VIII-1 states about partial radiography, I agree with vesselfab.
Here is how a portion of the 1977 VIII-1 UW-11(a) (5) (b) reads:
……………partially radiographed. This shall consist of a radiographic examination at least 6 in. (152mm) long of any section of the weld picked at random, plus a similar examination of any intersections of the weld with all Category A welds in either of the sections being connected. Acceptance standards for partially examined welds shall be as set forth in UW-51 for full radiography……………


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[jberens]

Thanks for the code verbage. What was the sentance leading into "...........partially radiographed" at the beginning?

 

[CodeRef]

Here it is for your review.......
Category B or C butt welds [but not including those in nozzles or communicating chambers except as required in (2) above] which intersect the Category A butt welds in vessel sections or heads or connect seamless vessel sections or heads shall be............. partially radiographed.

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