Closure rings and Communicating chambers

[Cluain]

Can anyone tell why I can't use Appendix IX of ASME VIII-I to establish the thickness for side bars of a bustle style configuration similar to a Type-I jacket.

Also, can I use the weld sizing (Z) for the bustle to bar attachment and (Y) for bar to shell proper.Is the use of a single fillet(Z)weld for bustle to bar prohibited merely because it’s a communicating chamber and not a true jacket?

Note: Fluids or gases are communicating directly with shell proper via bustle inlets.

 

[SnTMan]

Cluain, I am not familiar with the "bustle" terminology, however I have in the past used Apx 9 to design elements of a distributor belt or so-called vapor belt for heat exchangers, which are really just communicating chambers. I think, even though these are not separate chambers as a jacket is, there is useful guidance in Apx 9, as other portions of the Code are not especially helpful. I don't quite understand why the single fillets seem to be allowed in Apx 9, but I would avoid them.

I would probably get a buy-in from my AI before proceeding too far with this.

Regards,

Mike

 

[Cluain]

Thanks Mike,

My apologies for not using ASME terminology; I should have referred to the bustle as the outer jacket wall (tj) and the side bars as the closure members (tc). For clarity I am looking at Fig 9-5 skt (d-1).

The AI believes that I should be using UG34 to establish the closure member bar thickness in conjunction with Fig 13.2 skt (a) thru (f) for the attachment of the outer jacket wall.

Since there is nothing specific in VIII-I in relation to the application of this chamber (other than communicating chambers I thought I was using good engineering practice (U-2G) by utilizing Appendix IX.

The mere fact that there is no pressure differential or that the chambers are not independent has no real relevance when approaching it from pressure retention point of view.

I am reluctant to concede the points (which the AI makes) that the side bars (closure bars) are more indicative of flat heads and that a single fillet is unacceptable for the attachment of the outer jacket wall.

It is very clear to me that UG 34 will boot me into UG 39 which in turn will boot me into Appendix 14, not to mention that an integral attachment is required.

I too have reservations about using a single fillet (Z) for the outer jacket attachment; however, I trust that ASME would have eliminated this attachment configuration had they felt it unsafe to use.

Again, thanks you for the response!

 

[SnTMan]

Cluain, I understand your dilemma. However in the end it probably is more important what your AI thinks than what you or I think

Good luck.

Mike

 

[vesselfab]

APPENDIx 9 IS CORRECT for jackets.

attachment weld sizes, attachment types, thickness of closure bars, need to be exactly like the pictures shown and calculated per appendix 9 using only sect VIII div 1 material

IF IT'S A COMUNICATING CHAMBER...WELL THEN THAT'S ANOTHER SET OF RULES.

 

[Cluain]

AND WHAT PREY TELL, ARE THOSE RULES?

I don’t accept that the closure bar is a flat head!!!

 

[vesselfab]

i have no idea what a bustle bar is or how it is different than a jacket closure bar. whether it's inside outside or where it is. if it's not a jacket and you're using attachment detail that does not meet app 9 details...well that should be explanation enough.

sorry can't be more help

maybe a state/jurisdiction guy could help you out

 

[Cluain]

VesselFab,

I thought I clarified the terminology in my first response to Mike.

Again, it’ similar to Type 1 style jacket, in fact it’s identical in everyway to a jacket except holes are in the “shell proper” to allow gases or fluids to communicate with the interior shell. And, for the record, it meets all design requirements plus attachment details as prescribed per Appendix IX.

Respectfully, neither State guy nor AI can help here. Only an official ASME interpretation can help.

Regards..