RE: Unsustained Loading -Flange Pressure Rating

From: <Saha>
Date: Tue Aug 16 2005 - 08:41:00 EDT

Normally people do not check flange loading for occasional loads like surge.
Usually surge loads are quite high and flanges cannot be designed for that due to economic reason.

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From: <a href="/group/PipingDesign/post?postID=IKnVF-Jw9SW4K8cff1Mu9TuvKO4kRboUeOjh0RkUsSdSiKBsrf64zVTEet3raVApEuwRX6aQwmXWUielXvbSxld23H-Q-5U">PipingDesign@yahoogroups.com</a> [mailto:<a href="/group/PipingDesign/post?postID=IKnVF-Jw9SW4K8cff1Mu9TuvKO4kRboUeOjh0RkUsSdSiKBsrf64zVTEet3raVApEuwRX6aQwmXWUielXvbSxld23H-Q-5U">PipingDesign@yahoogroups.com</a>] On Behalf Of blenrayaust
Sent: Tuesday, August 09, 2005 3:23 AM
To: <a href="/group/PipingDesign/post?postID=IKnVF-Jw9SW4K8cff1Mu9TuvKO4kRboUeOjh0RkUsSdSiKBsrf64zVTEet3raVApEuwRX6aQwmXWUielXvbSxld23H-Q-5U">PipingDesign@yahoogroups.com</a> Subject: [PipingDesign] 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.

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Yahoo! Groups Links Received on Tue Aug 16 08:41:00 2005