Section III, Jacket penetration weld details

[trottiey]

I'm a bit stumped as to how to design the weld joint for a nozzle penetration through a jacket wall under Section III Part ND. Under Section VIII, this would be straightforward: Appendix 9, preamble to 9-4 gives you exemptions from the basic code, and Figure 9-6(a) is pretty close to what I would like to do.

But since Section III doesn't have an analogous appendix, I take it that jacket penetrations are treated like any other category D weld? If so, then the ND-4244 figures would appear to require a fillet or radius on both sides of the jacket wall. That inside fillet is not absolutely impossible, but kinda tough. Is there an exemption somewhere that I'm missing?

Another caveat is that Appendix 9 seems to assume a thin and flexible jacket wall. In my case, my jacket wall is a flat plate at that point, so it's 1/2" thick, about as thick as my nozzle wall. Does that make the inside fillet more advisable?

 

[Duwe6]

Write an RFI - Request for Information - to the Design Engineer, as to how this weld can be made 'legally'. He will probably have to involve his ANI - Authorized Nuclear Inspector.

Be sure to mention [or include] your welding procedure for an open-root weld [single side welding, like all pipes] that achieves 100% Joint Efficiency. That, plus a large reinforcing fillet on the OD that will smoothly distribute the membrane stress from the jacket into the nozz.

 

[trottiey]

I am the design engineer. But involving the ANI is somewhat difficult in my country; we don't use the same system.

 

[cloa]

Which country?