RE: What is an Expanded Joint ?

From: <Steve>
Date: Thu Sep 14 2006 - 17:24:00 EDT

Hi Ken

While I do not have B31.3 at hand so cannot check context, I think the reference is to the joint formed when a tube is expanded into a drilled hole or tubesheet. Expanded joints are by far the most common means of making a connection between tube and tubesheet in shell and tube heat exchangers, not to mention boilers and other process plant equipment. The tube is normally expanded by rolling the tube bore, which causes the tube to expand and creates an interference fit between the tube O.D. and the receiving hole.You should find any number of references on the internet.

Cheers

Steve

>From: "umesh k.n." <umesh_kn@yahoo.com>
>Reply-To: PipingDesign@yahoogroups.com
>To: PipingDesign@yahoogroups.com
>Subject: [PipingDesign] What is an "Expanded Joint" ?
>Date: Wed, 13 Sep 2006 22:39:01 -0700 (PDT)
>
>Fello members,
>
> ASME B 31.3 Process Piping says a follows:
>
> 313 EXPANDED JOINTS
> (a) Expanded joints shall not be used under severe cyclic conditions.
>For other services, adequate means shall be provided to prevent separation
>of the joint. If the fluid is toxic or damaging to human tissue,
>safeguarding is required.
> (b) Consideration shall be given to the tightness of expanded joints
>when subjected to vibration, differential expansion or contraction due to
>temperature cycling, or external mechanical loads.
>
> What it is talking about?
>
> Is this "EXPANSION JOINTS"? (METAL BELLOWS?) OR Something else?
>
> If it is not a Bellow, can any send me a link or picture of these
>"Expanded Joints"?
>
> Rgs,
>
> Umesh Ken,
> Sr. Piping Specification engineer,
> Brisbane, QLD-4000, Australia.
>
>
>
>---------------------------------
>Talk is cheap. Use Yahoo! Messenger to make PC-to-Phone calls. Great rates
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>
>[Non-text portions of this message have been removed]
>
>
>

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