Fixed Tube Sheet Heat Exchanger Flexible Shell Elements. Axial load

[DK44]

1. In the design of Flexible Shell Element (Expansion Bellows) by FEA, for Fixed Tube sheet Heat Exchangers, TEMA RCB-8.5(2) gives following formula for Axial Load calculation:
F axial = (Pi/4)*G^2*100lbf/in^2.

2. In this equation the internal pressure is not figured, instead a term 100 lb/in^2 is used. Calculation without the use of internal pressure does not appear to be in order. Also assuming 100 lb/in^2 generally for all caces does not appear to be appropriate.

3.Can we use Exchanger Shell side Design pressure in place of 100 lb/in^2 in the formula.

Request guidance in the above calculations.

 

[SnTMan]

DK44, I think you are going to need to get your guidance from TEMA. This is a highly complex analysis, I suspect the author(s) could best answer your question.

Well, that's just wrong. What the analysis is doing is, is determining the spring rate of a known geometry. A known load is applied and, from the FEA, a displacement is found. The spring rate is then calculated as per 8.5(4) & subsequent.

So, no, the design pressure is not used for this step.

Regards,

Mike



The problem with sloppy work is that the supply FAR EXCEEDS the demand

 

[SnTMan]

Actually, I suppose the use of the given pressure is arbitrary, after all, you are applying a load and "measuring" a deflection.

Why the given, 100 lb/in^2, rather than some other value you would have to ask the author(s).

The problem with sloppy work is that the supply FAR EXCEEDS the demand