100% RT Vs. Full RT 3

[Meck91]

Folks,
I need to get some information on 100% RT Vs. Full RT with respect to ASME Section VIII Div. 1 Para. UW-11.
Some take 100% same as Full RT, some not.

Below is the detail I got from one the discussion forums. Is this interpretation correct or any further addition/revision to it.
“Let us consider a cylinder on a vessel for a certain length and it has 4 Cir. Seams and 4 Long. seams.
If the vessel calls for FULL radiography, then a spot (I repeat a spot, means not Spot radiography, it is a portion, say 100 to 200mm) on all the 4 cir seams, 4 long. seams have to be radiographed and all the T joints have to be radiographed.
If the vessel calls for 100% radiography, then the entire length of the Butt joint welds have to be radiographed (thro full length)”.

Would appreciate your help.

Meck91

 

[vesselfab]

As a long time fabricator we take the code at it's word

full radiography is spelled out in uw-11(a)
all cat a & b welds and nozzle welds over 10" (?) maybe 12

if you do partial at T joints per uw-11(a)(5)(b) well that is under full but generally that is consider partial

what we consider 100% radiography is every stinking pressure containing butt weld on the job with no size exclusions

 

[vesselfab]

fogot to add

if the client has not specified the amount of radiography and we wish to have 1.0 joint efficiency, we use the partial at T joints per UE-11(a)(5)(b) and 100% longitudinal and stamp the vessel rt-2

 

[metengr]

If you review UW-11 (a) there is no mention of the term 100% RT only Full. So, since 100% RT is undefined in Section VIII, Div 1 Part UW-11, it cannot be used to mean anything with reference to the current Code. A 100% of what a spot or long seam???

If I have an engineering specification that requires 100% RT, this could mean the entire vessel, outside of Code minimum requirements, and would be the owner's decision to do.

 

[chaulklate]

Just to reinforce what is already stated...

Full is NOT 100%, and 100% is NOT Full.

Full is RT-1 as per UW-11(a)- full longs, full circs, nozzles greater than 10" NPS or >1.125" wall thickness

100% is not a code term and is therefore ambiguos, but has come to be understood as radiograph all long and circ seams on the vessel regardless of diameter or thickness.

 

[DG72]

While I agree that code doesn't define 100% RT, I don't consider 100% to be ambiguous--it means all; no code exemptions for small nozzles (it's okay to go above and beyond code minimums). I agree with vesselfab.

Whether code recognizes the term, or not, doesn't matter. As long as you are correctly assigning joint efficiencies to the component being designed and properly listing it on the data report, you are in perfect compliance with ASME code.