Issue of tube box flange bolt spacing in SW6 calculations
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A small fixed-tube-sheet heat exchanger with a DN325 diameter was designed. Since the shell was made directly from tubes, tube flanges were chosen as the tube box flanges; however, when performing checks using SW6, the flange spacing was always found to be insufficient, as it was considered too small. It turns out that reducing the number of bolt holes from 12 to 4 is still not acceptable. Please discuss what I should do The flange thickness has also been verified.
No way, please check your input data more carefully. I have made many pipe flanges as well, and I have never encountered this situation before.
No way, is the one used by the original poster pirated? We haven’t encountered such an issue either; let’s check again to see if there’s a mistake in the bolt center distance input
With SW calculations for flanges, it is possible for the bolt spacing to be incorrect; however, in most cases the spacing is too large. If it is too large, as long as the cross-sectional area is sufficient and the stresses can be managed, then the bolt spacing is not a concern.
I really haven’t encountered this issue before; I’ll check it carefully
I’m sorry for the trouble caused; I’d like to thank everyone up above for their analysis. Today, I accidentally realized that the data I entered was incorrect; the bolt center distance should be 600. I calculated it based on a bolt diameter of 22, which led to a huge mistake!
Why calculate the bolts unless non-standard flanges are used? Besides, flanges calculated using the SW6 standard are all unqualified; it’s sufficient to use standard flanges directly, which saves hassle
It’s strange! SW6 gives an incorrect value for the bolt spacing; after calculating it myself using the formula, the proper spacing is 104 mm, whereas its calculation resulted in 5.8 mm, which is clearly wrong! Second: The flange thickness was found to be within acceptable limits the day before; yet when the data from yesterday was retrieved again today for recalculation, the thickness was once more not up to standard! !
For flanges based on the SW6 calculation standards, it seems that there is always a problem with insufficient bolt spacing; we encounter this issue quite often when performing calculations.
For the 325 heat exchangers I’m working on now, when using standard flanges with PN16 rating, the flange spacing and thickness are insufficient; whereas with PN25 rating, the flange thickness is not adequate. . I’m very torn.
The bolt diameter of the pipe flange is relatively large; it can be reduced slightly, which helps to decrease the thickness. At the same time, the outer diameter of the pipe sheet also decreases. Although the equipment isn’t very large, saving even a little money is still beneficial