Can someone help clarify/simplify the difference between RT1,RT2,RT3,RT4 from ASME sec. VIII UG-116. Basically if someone could provide me with an example of an RT1 vessel compared to an RT4 vessel, that would probably clear things up for me.
I may be able to help just a little, however, your AI should be able to clarify and help you fully understand the requirements.
RT1 - 100% RT of shell seams and head to shell welds and 100% joint effeciencies on shells and heads.
RT2 - 100% RT of shell seams and spot RT of head to shell. 100% effeciencies for joints can be used here under UW11(a)(5)(b). Check out authorisedinspector.com for a very good explaination of the provisions of UW11(a)(5)(b).
RT3 - Spot RT and joint effeciencies (70%) in accordance with table UW 12
RT4 - basically when none of the above can be applied.
Hope this helps some. This is the way that I understand it.
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