Ansi/kellogs method is a widely used way to check flange joint, but different standard, or client specification could use different allowable. Now the ASME BPVC VII UG-44 suggest 2.2 for B16.5 #150 and 1.5 for most of the others; DNV suggested 1.5 many years ago; etc..
It would be very usefull if the user could set the allowable ratio for each rating.
Please be aware that the method in UG-44 is under revision. See more details here, where the balloted version of the code case is shared(see user TGS4). The new version allows for more loads under UG-44
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