Unsustained Loading -Flange Pressure Rating

I have a question related to the design rating of flanges when exposed to occassional unsustained loading. The loading I am considering comes about as a result of a surge event. My reading of ASME B31.3 and Dr Brecht's book is that this is covered by the clause that allows such infrequent loadings to increase the longitudinal stress up to 1.33 times the design stress. However I can find no specific reference to flanges when considering such an event.

I have come to the above conclusion as a fully butt welded system is rare in industry . Ergo flange systems abound that may be so loaded. I have posted the question on anumber of forums however the silence is deafening. If you could assist it would be appreciated. Received on Mon Aug 08 19:22:00 2005