Derating of ASME Appendix 2 Flanges for External Loads
Derating of ASME Appendix 2 Flanges for External Loads
(OP)
Currently I utilize the "Equivalent Pressure Method" to derate all of my ASME Code Appendix 2 flanges. It is very easy to use but it is also VERY conservative.
I understand that you can also use the "Equivalent Axial Force Method": F = 4M/G
Where:
M = moments acting on the flange
G = mean gasket diameter
F = equivalent axial force
The only problem is I am not completely clear on how to use this method. Does "M" represent the sum of all my external moments? And how do I apply this equivalent axial force to my flange to make sure it can take the loads?
Does anyone utilize this method or should I stick with my current analysis?
Thanks!!
I understand that you can also use the "Equivalent Axial Force Method": F = 4M/G
Where:
M = moments acting on the flange
G = mean gasket diameter
F = equivalent axial force
The only problem is I am not completely clear on how to use this method. Does "M" represent the sum of all my external moments? And how do I apply this equivalent axial force to my flange to make sure it can take the loads?
Does anyone utilize this method or should I stick with my current analysis?
Thanks!!





RE: Derating of ASME Appendix 2 Flanges for External Loads
Your 'equivalent force', seems to be only part of a solution. The equation terms are same as Kellogg, when
4/(pi.G^2) is factored out.