RT-1 and 100% and UW-11(a)

[TexasChris11]

I have looked ad UW-11(a), and it is my understanding that an vessel requiring Full Radiography (RT-1) has all the but welds radiographed; except for categories B, C in nozzles less than NPS 10.

My question is.. Why does RT-1 Code exempt these nozzles?

 

[TexasChris11]

Is UT a better NDE procedure for nozzles less than 10 inches, if the vessel is called out to be 100% RT, instead of RT-1.

 

[ukmet]

UT is not required by ASME Sec VIII Div. I unless and until excess for RT is not available. As a good engineering practice you can go for UT for full penetration joints where there is no other good way to check for flaws.