ASME Flange Rigidity check is applicable for rectangular flanges?

[charlesbuk]

Is the flange rigidity check of para 2-14 of ASME VIII div.1 appendix 2 applicable also for the rectangular flanges? (My question regards the cover plate of an aircooler heat exchanger header)
Someone can help me?

 

[SnTMan]

charlesbuk, there is a lot about Appendix 2 that does not apply directly to rectangular flanges, and the equations as given for rigidity I suspect would not either.

Why not design your cover to UG-34?

Regards,

Mike

 

[charlesbuk]

The cover has been designed with UG-34,
but I would like to know if I have to perform also the check of rigidity according to 2-14, considering that Appendix 2 is mandatory, what do you think about?

 

[SnTMan]

charlesbuk, I don't see that UG-34 references in any way rigidity calculations, therefore they are not required.

Of course, you are free to do any calculation you wish. Regarding the rigidity calculation, how confident are you that such quantities as the constants and rigidity factors etc are the proper values for rectangular flanges? Is it just a "numbers in, numbers out" kind of calculation?

Regards,

Mike

 

[DSB123]

Just an observation - but how can a rectangular flange be construed as being a circular flange such that circular flange equations can be used?

 

[charlesbuk]

Mike,
regarding the previous matter, I did some additional check.
The design of the cover can be made using UG-34,
but UG-34 does not give information about the design of the flange to which the cover is bolted.
So in my opinion the rectangular flange welded to the header shall be designed using appendix 2 (see 2-1 (d)). Conseguently also rigidity check of 2-14 shall be performed.
Moreover all the parameters in the formulas of rigidity factors can be easily applied to rectangular flanges.
Everyone's opinion is welcome.

regards

 

[heatexguy]

Non circular vessels shall be designed per Mandatory Appendix 13.
See 14-4(i). Flanges designed per U-2(g). Appendix 2 is for circular flanges only, see 2-1(a) regarding "circle". We design rectangular flanges per U-2(g) following guidelines from the book "Design of Process Equipment" by Kanti K. Mahajan. Air cooled heat exchangers Part C-Coverplate and flange design for header box. We have never had an issue with the AI or the Customer in doing so. In my opinion a flange rigidity check per Appendix 2 is not required.

 

[heatexguy]

I'm sorry, I should have referenced 13-4(i).