Evaluate ASME B16.5/47 flanges per ASME BPVC VIII-1 UG-44(b)
ASME B31.3-2022 F312 FLANGED JOINTS suggests using UG-44(b) "for qualifying piping external loadings on welding neck flanges". UG-44(b) is a modification of the very conservative equivalent pressure method.
perhaps is like this idea: Flange Ansi check as per UG-44: setting a user ratio for each rating
Sean, please provide more specific information what you would like changing.