ASME Section VIII Div 1. - UW-13.2 Attachment - Heat Exchangers

[Par129]

Good Morning,
I am currently working on a vertical orientated heat exchanger (evaporator) and have a question regarding the tube sheet to shell welds. This heat exchanger has a section of shell on both sides of the tube sheets and I intended to weld both sides via UW-13.2 (d). I have been informed the if we are going to weld per UW-13.2 (d) on both sides of the tube sheet that dimension tp must be multiplied by 2. This is an issue as it would drastically increase the tube sheet thickness well beyond the required thickness per ASME calculation. In the past we have not had any trouble overlapping dimension tp so long as at least tp was maintained between the two welds. I cannot find anything in Section VIII Div 1. to confirm or deny my findings. Any assistance would be appreciated as I look forward to resolving this issue.

 

[Afox88]

My company does not do 2x tp. I could not find anywhere in code that it tells you to do 2x tp, although I honestly did not look too hard because I do not think it is there.

 

[SnTMan]

Par129, for this construction, I have always taken "tp" as nominal between toes of the two welds, not two times tp. Note that tp can be as small as 1/4". Drastically increase tubeshseet thickness? Hardly seems like it, but can't say for sure.

Anyway, I have always used tp x 1.

Regards,

Mike

 

[Par129]

Thank you for the response. Do you think my best way to go about resolving this issues is making them show to me where in the code book it says it needs to be 2x tp?

 

[SnTMan]

Par129, you don't say which party takes that position. If a client it might make sense to just comply. If a co-worker, well, I doubt anybody can show you where the Code requires 2tp, I don't believe it does.

Regards,

Mike

 

[Par129]

Mike,
Thanks for the response. In this situation it was the AI reviewing the documentation of an already completed tube sheet. If it need to be 2tp we needed to scrap the completed part and start over. I have received word from the AIA informing me that we are building to code with 1tp. Have a good day.

 

[SnTMan]

Par129, we win one, once in awhile