Calculations as per UG-39(b)(1)

[ting123]

Dear Colleagues,

I am designing a Horizontal pressure vessel and I have a 4"nozzle on the top of the blind of another 6"nozzle. The 6" nozzle is on shell. This leads to the a large opening in the 6" blind flange and as per UG-39(b)(1) this is to be designed as per Appendix-14 and Appendix-2. But when I read these paragraph these are applicable only for welded flat heads. Nothing is mentioned for bolted flat heads. I have attached the sketch for the same. Can someone help me to get a solution for this.

 

[SnTMan]

ting123, if you want to ignore the reinforcing contributed by the nozzle, you could design as a ring flange per Appendix 2, for example, Fig 3(a). The thickness of a standard blind flange may or may not make, if not you would have to make your own. Not really a big deal.

If you are for some reason married to a standard blind and its thickness is not sufficient, you will have to consider the reinforcement contribted by the nozzle, per U-2 (g), that is, there are no specific rules for this.

Regards,

MIke