Radiography

[darrenyee88]

Can I know what is the difference between Full radiography and 100% radiography?

 

[SectionIX]

They are one in the same.

Full radiography, Per ASME Section VIII, Div 1 (UW-11 and 12)is the more common term.

 

[darrenyee88]

Oh i see. I was told by that for full radiography is only for butt weld that exceed certain thickness. However for 100%, means all the butt weld need to be radiograph no matter what is the thickness . I read UW-11 and 12 but 100% was no mention. so i am abit lost .

 

[Duwe6]

Sorry, but they are NOT the same. Under ASME "Full Radiography" usually entails 100% of all longitudinal seams and all long. to circumferential seam junctions; BUT only requires 'spot RT' of the circ. seams. And all of these seams are full-penn butt welds. See VIII Div-1 QW-51.

And "100% RT" adds 100% of the circ. welds, versus the 'spot RT' of "Full RT".

 

[SnTMan]

For Sec VIII, Div 1 work 100% RT is generally taken to mean that the exemptions of UW-11(a)(4) for Cat B & C welds are not taken, these are RT'd. This can vary by organization however. Best to ask the question.


Rgards,

Mike

 

[DekDee]

I agree with Duwe6,
Both Full and 100% (and Spot) are noted in ASME VIII whereas the B31 piping codes reference 100%, Random or Spot radiography,
Cheers,
DD

 

[marty007]

DekDee, I think it goes a little bit beyond that. The difference you mention is between RT-1 and RT-2. Following is my interpretation.

Full Radiography

ASME VIII-1 has two meanings for full radiography:
[ol 1]
[li]RT-1: Full radiography of all long and all circ seams, but with some exceptions (eg: nozzles and communicating chambers not larger than NPS10)[/li]
[li]RT-2: Full radiography of all long seams, but spot radiography on circ seams, but with the same exceptions above (eg: nozzles and communicating chambers not larger than NPS10)[/li]
[/ol]

So, it can be called full radiography in either case, but you are still leaving out some welds (small nozzles for example)

100% Radiography
Some customers for some applications require absolutely every butt weld to be radiographed, not allowing for any of the exceptions allowed by ASME VIII-1 for full radiography. For 100% radiography I would be performing radiography even on those little NPS2 pipe to RFWN nozzle welds.


Just my opinion... I'm sure others read this differently. Normally when I see 100%, I confirm whether they actually meant full radiography as defined by ASME as either RT-1 or RT-2. If they actually mean 100%, they'll reiterate it.

Marty

 

[DekDee]

marty,
I have mentioned no differences - just agreed with Duwe6.
The most basic answer to the OP is if "Full" radiography is required everything noted in UW 11 must be radiographed.
If 100% radiography is required all butt welds nominated for "spot" radiography must be radiographed 100%.
If nozzles are not nominated for any radiography at all I can see nothing in ASME VIII requiring it.
The only reference I can find to 100% radiography is in UW-52 Spot Radiography,
Regards,
DD

 

[darrenyee88]

Thanks All.

 

[GenB]

100% RT and full RT are the same terms. how it is applied and required by Code or to customer's specifications or requirements are different cases.

 

[david339933]

Marty hit it on the nose.