Mawp UG-99 note 35 and B16.5 vs appendix 2

[Ehiman1]

Hi everyone,
I have a unusual case, with a small pipe with two flanges ansi b16.5 3” #300 and two blinds (equipment ASME VIII div1 stamp).
Pressure is 8 barg and temperature 70 C material Carbon steel.
In this case I need to verify standard flange against external loads with UG-44b and verification isn’t ok, so in order to save the flange and don’t increase the rating I verified flanges with Appendix 2 ASME VIII div1 and everything is ok.
But doing so I noticed that the MAWP is very high and higher than that one shown on flange B16.5 as well. In this case can I use note 35 of UG-99 and put design pressure equal to MAWP to have a reasonable value of Mawp and hydrostatic test? Does my reasoning can be considered ok?

Thank you

 

[TGS4]

What kind of loads did you have on this flange that it doesn't pass the UG-44(b) calculations for a Class 300 flange at a pressure if only 8 barg? The rating pressure for that flange is 51.1 barg! That, plus the F_M factor leaves you a boatload of available equivalent pressure for external loads...