Interpretation: VII-1-04-61 Subject: UHX-10(a)

[solidhardhead]

Interpretation VII-1-04-61 states that a no-tubes-in-window (NTIW) baffle design does not fall within the scope of the code for tubesheet calculations on heat exchangers. As a result I must fall back on TEMA for my tubesheet thk calculations, correct?

If so, does the same rule apply to exchangers that do not have a full shell of tubes? i.e. exchangers with large entrance and exit areas or tube patterns which are not "uniformly perforated over the entire nominally circular area" for heat transfer purposes.

Thanks

 

[dgrande]

I believe that you are interpreting both of these items correctly.

 

[SnTMan]

If that's the case I haven't as yet seen any HX in my work that meet UHX-10.

Regards,

Mike

 

[Konrad]

And for me it's the only hope to make a HX right: to exempt it from UHX.
Konrad

 

[dgrande]

Agreed. Para. UHX-10 is new & the majority of my heat exchanger work will be exempted

 

[SnTMan]

We're back to TEMA. So what was the point? Yeah, I've read the "whitepaper".

 

[solidhardhead]

So are you saying that you are strictly using TEMA for your tubesheet calcs when your bundle does not meet the UHX criteria?

 

[dgrande]

This is only my thinking, but I believe that, in time, ASME will expand upon Part UHX to be more applicabe to a variety of geometries. For now, I think that it is a work in progress. Unfortunately for us, it's a pain in the arse to figure out where to apply it & where not to.

 

[SnTMan]

solidhardhead, I think it's perfectly reasonable under U-2(g), and I think its MUCH better than "rolling my own". After all, it was the industry standard for many years.

dgrande, no doubt, but we all have HX we need to design NOW.

Actually, I run tubesheets both UHX and TEMA, to try to get a feel for the differences, as my experience with UHX is pretty limited.

Regards,

Mike