ASME VIII-1 Appendix Y or Appendix 2 with UG-34

[takio]

Hello,

I have a drawing as below.

and I want to design the upper flange.

It looks like Appendix Y-Class 3-Category 3 is applicable for this drawing. and it has an equation for bottom flange thickness calculation as well.
and someone said i could use appendix 2 with UG-34, saying the upper flange is a blind flange.

Are both of them applicable for the configuration in the drawing?

Thank you for your time.

 

[cbPVme]

Definitely Appendix Y as there is metal to metal contact outside the bolt circle. The upper flange is not a blind flange, it's a loose ring type.

 

[takio]

Thank you so much for your help!!