Nozzle Weld Requirements for Jacketed Vessel

[rjw57]

Can someone please point me to welding requirements for jacketed vessels where a nozzle penetrates both the shell and the jacket. I am unable to locate it in the section VIII div 1 code book (disclaimer - I am not a full time PV engineer ;^) ). Thanks for your help.

 

[trottiey]

Appendix 9, paragraph 9-6.

 

[rjw57]

@ trottiey,

Let me be more specific. I have a nozzle which penetrates both the jacket and the shell radially and perpendicularly. The nozzle extends beyond the outside of the jacket and the inside of the shell (both cylindrical) so in other words, the nozzle is not "abutting" either the shell or the jacket. How do I comply with UW-16 regarding the nozzle to shell weld since I am unable to obtain a backing weld due to the method of construction of the PV. In other words, when the jacket is placed over the shell (concentrically), and the nozzle is inserted through the opening, I am not able to weld at the backside of the shell to attach the nozzle since the weld would be in the space between the jacket and shell. Hope this makes sense to you. I think I would like to throw a backing strip on the unreachable spot and then do a full pen bevel weld to attach the nozzle to the shell, but I can't validate this approach in the code. Any thoughts?

 

[trottiey]

I know exactly what you're talking about. The soluton you describe is permitted by interpretation VIII-1-86-89, and is shown in Fig 9-6(a). You need a fillet on top of your bevel.

Now if you can figure out how to solve the same problem under Section III, I would be very grateful if you could post it to thread794-291562

 

[vesselfab]

Can you put a ring larger than nozzle from jacket to shell.

this allows you to complete the nozzle to shell weld as usual and then insert the ring to shell and weld single bevel & fillet on inside of ring to shell and a single bevel and fillet to outside of ring to jacket.

 

[rjw57]

@vesselfab,

Yes, this would be possible, but unless it was absolutely required, I would prefer NOT to do this.