Re: 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.

Paul

> >except I dont see any
> >welding on the failed flange and i dont see where the welding
relates.
> You may be right. I thought I was seeing the remains of a fillet
towards
> the bottom of the pipe in slide 2. There's nothing on the ring itself
> that I can see. Wonder if this is a lap joint ring mated to an
ordinary
> slip-on or weld neck.
>
> > (i cant see the flange ring welded to the pipe being the case
because the
> >flange ods line up and the bolt position has not changed radially (no
> >stretch) and the pipe hasnt "shrunk").
> If it were a lap ring , overtightening would produce the radial cracks
at
> the bolt holes. There would be a gap between the ring ID and the pipe
> wall which would open up under tightening as the the ring ID rotates
out
> and away from the pipe OD.
>
> >It strongly appears to be an illegitmate slip on ring flange. if made
out of
> >improper material the failure would occur as seen at the stress
raisers of
> >the holes.
> Bang on. Looks like cast iron maybe with a coat of primer. I wonder if
> that light-colored stuff at the OD is caulk, laid in as a desperation
> measure.
Received on Thu Jan 29 17:17:00 2004