Basis for ASME B16.5 Flange Ratings 1

[roca]

Can anyone shine a light as to how the flange pressure - temp ratings in B16.5 are derived?
Calculations?
Flanges tested to destruction?
Everyone I ask doesnt actually know

 

[metengr]

Yes, by calculation from established equations in Annex B of ANSI B16.5. All of the information for establishing pressure-temperature ratings is contained Annex B of ANSI B16.5. The title of this Annex is "Method used for Establishing Pressure Temperature Ratings"

 

[PAN]

In ASME B16.5 - 1996 Edition, the subject is in Annex D.

 

[carthago]

Wher these flanges calculate once and for all using ASME VIII div.1, appendix 2 ????/

 

[Christine74]

ASME flanges generally will not calculate for their stated B16.5 pressure-temperature ratings when calculated per ASME Section VIII-1.

-Christine

 

[carthago]

Sorry, a mistake, so I will re-state my question:

Wher these flanges ALREDY AND BEFORHAND, ONCE AND FOR ALL FOR A RANGE OF PRESSURES AND TEMPERATURES, calculateD using ASME VIII div.1, appendix 2 ????/

I OTHER WORDS WHAT IS THE BASIS AND THEORY BEHIND B16.5

Something I now , is that ASME VIII -Appendix 2, is based on LA FORGE (?) ....

 

[wsmith22]

No, they are calculated per ASME B16.5. The equations in the annex are different than the procedure used in Section VIII.

This brings up my post from the other forum. Appendix 2 added flange rigidity as a mandatory calulation. We design self energzing (o-ring) flanges and have never had an issue with leakage due to flange distortion. Now, for some reason, ASME is forcing us to increase our flange thickness. What is the reason for this change? We have many flange in stock that are now scrap.

Also, ASME B16.5 flanges are allowed per Section VII even though they fail the Appendix 2 calculations. This is a major contridiction.

 

[metengr]

I disagree. Carefully read Mandatory Appendix 2, paragraph (c). It provides the rationale for the calculations and exemptions to using the calculations.