Like example C on the following sketch?
<a href="http://www.pipingdesign.com/drawings/flange_assembly.jpg">http://www.pipingdesign.com/drawings/flange_assembly.jpg</a>
I had already eaten all my Crayons so I had to use hi-liters for colour.
Paul
> Paul
> guess I didnt explain clearly. I think it is probably a lap flange or
> similar stub end with a plate flange fitted. If the plate flange does
not
> have a correctly dimensioned chamfer or bevel on its inner bore, it
will
> bind on the stub end fillet radius, preventing the flange inner face
from
> bearing on the outer face of the stub end. But with some big spanners
we can
> crank it up (as we do) which will crush the flange bore onto the stub
> fillet, and bend the flange into a cone shape. The tension on the
flange
> bore could easily cause the cracks shown provided the stub end doesnt
> collapse first. Diagnosis - wrong flange for the job. Obviously,
because the
> bloody thing broke.
>
> Hows that for a stack of interdependent assumptions based on a couple
of
> happy snaps?
>
> I wonder what the real cause was..........
>
> Cheers
>
> Steve
>
>
> -----Original Message-----
> From: Paul Bowers [mailto:pbowers@pipingdesign.com]
> Sent: Friday, January 30, 2004 11:17 AM
> To: <a href="/group/PipingDesign/post?postID=82Eybrf1r5S4W_tGry0-CwUIqrNiIY88cqtQI5twhYPXK3K8OciSwEIDcKmC6e-JzLJ55mLh9lIcydspDhxiQavp">PipingDesign@yahoogroups.com</a>
> Subject: Re: [PipingDesign] Flange Failure Images
>
>
> Assuming this is 10", 12" or 14" line size (12 bolts) and it's a Van
> Stone/lap joint assembly (as Steve considered and then dismissed),
the
> stub end should be at least 5" long, meaning we should see a butt weld
> close to where it's written "SX" with an arrow and "6" underneath.
> That's why I speculated that it might be a butt type angle ring, which
> is only 1.5" face-to-face - the butt weld would be almost totally
> obscured.
>
> Or maybe it's this: <a href="http://www.ipp-inc.com/rev3/sose.htm">http://www.ipp-inc.com/rev3/sose.htm</a>
>
> The flanges definitely appear to be of different material and this
looks
> like a spec change interface.
Received on Fri Jan 30 11:02:00 2004
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