Heat exchanger expansion joints 2

[lukebaker]

Does anybody have a good reference for the design of thick walled expansion joints for a large diameter vertical heat exchanger? I am using APV to design the heat exchanger and I know I need an expansion joint, but part UHX in the code book is not very helpful as far as the design is concerned. Any help is appreciated.

 

[doct9960]

lukebaker,

Have you read Appendix 5 of ASME VIII-1?

How about EJMA? Also have a look into the literature in the US Bellows website...

http://www.usbellows.com/

 

[SnTMan]

lukebaker, I am not familiar with APV, I assume it is software. Appendix 5 contains mandatory
requirements for thick-walled expansion joints, but does not tell you HOW to do the calculations, nor does part UHX. I doubt EJMA will be of any help.

See also thread794-177673.

Regards

Mike

 

[eeromatti]

TEMA tells how to make calculations, but its very complicated procedure. EN 13445 is usefull too and as far as i can tell the method is very similar to asme. AD 2000 has also method for thick bellows.

 

[SnTMan]

FYI, I took a little time to run a test case in CodeCalc the other day, using Part UHX for the tubesheet calculations and with a flanged and flued expansion joint.

While I have not had time to study the calculations to my satisfaction, as the ouptut is voluminous, it appears that this software does pass the required variables between the fixed tubesheet and expansion joint calculations.

It further appears that it uses a combination of the ASME and TEMA calculations, that is, it calculates all the required UHX data, and then calculates any data required by the TEMA flexible shell element calculations.

Regards,

Mike

 

[francifo]

Dear Lukebaker,
I just had to use APV for a 2 tubesheets heat exchanger, but I switched to TEMA because the tubesheet thickness, according to the code and therefore to APV, results to be TOO high (260 mm thick !!!!).
So with TEMA I had only 110 mm thickness, that sounds ok.
Has anybody had the same problems with tubesheet according to the code?

 

[SnTMan]

francifo, my experience with part UHX (limited) is that tubesheet thickness could go either way compared to TEMA. UHX seems to allow some tubesheets to be so thin it doesn't make sense, like under 1 in.

Also, I have had almost none that, strictly speaking, falls into part UHX applicability.

I also usually calculate per TEMA and use the thicker of the two. Why be half-safe

Part UHX is, however Mandatory.

Regards,

Mike

 

[eeromatti]

francivo: I suggest you to verify your uhx calculation software/input.

 

[Bobfromoh]

Depending on what you are doing, The ASME tube sheet calculation may be mandatory. You can't choose the between the Code and TEMA anymore for new construction.