Re: [PipingDesign] cross country pipe line routing -- too much flexibility

From: <Theo>
Date: Sat Jul 16 2005 - 10:50:00 EDT

Chemical Processing of May 1998 carried an article by L.C. Peng "Piping Flexibility Basics--too much flexibility can be as bad as too little". See www.chemicalprocessing.com

Theo Schotten

> The 'over-design' is an interesting issue. I am interested in bounding
> this
> flexibility problem from another side. Isn't there some thing as too-much
> flexibility?. Example for a 3000 ft pipe one can theoretically put either
> one anchor or 3 anchors and keep the pipe stresses lower than the
> allowable
> . Of course the stresses in 3-anchor, with same number of elbows and
> offsets, would be higher than the 1-anchor system. Besides costs is there
> some consideration that should be a constrained - like maximum thermal
> movement between anchors ?. Most of the literature deals with the issue of
> minimum flexibility or maximum allowable stress and does not address
> 'maximum flexibility' allowed. Any opinions ?
>
> ----- Original Message -----
> From: "Arief Agung" <Arief.Agung@halliburton.com>
> To: <PipingDesign@yahoogroups.com>
> Sent: Tuesday, July 12, 2005 12:28 AM
> Subject: RE: [PipingDesign] cross country pipe line routing
>
>
>
> Hi Amarendra,
>
> I think, if the stress analysis already performed and the result is safe.
> Everything is OK, right?
> Be careful when putting the anchor and expansion loop. Consider to
> minimize
> the force acting at anchor or expansion loop.
> Beside of that the objective why you put anchor and expansion loop can be
> achieved. I mean sometimes although we didn't put any anchor or expansion
> loop, the system is still safe so why we need to put them (Over design).
> For
> example, when expansion loop location near bends or slopes, the
> displacement
> is transferred to bends or slopes so the expansion loop doesn't have to
> work.
> Correct me if I'm wrong.
>
> Regards
> Arief
>
> --Original Message-----
> From: PipingDesign@yahoogroups.com [mailto:PipingDesign@yahoogroups.com]
> On
> Behalf Of amarendra kumar
> Sent: July 8, 2005 10:29 AM
> To: PipingDesign@yahoogroups.com
> Subject: Re: RE: [PipingDesign] cross country pipe line routing
>
>
> Hello Arief,
> I have already done the stress analysis of the system on CAESAR-II and the
> system is safe . But due to change of profile of the land you are never
> able
> to feed the exect system giving the exect elevation changes and direction
> changes. I have put expansion loops al 500 m span.
> Just I want to know practically what problems may arise if the location
> of
> some of the loops and anchors are near bends and slopes.
>
> Amarendra kumar
>
> On Tue, 05 Jul 2005 Arief Agung wrote :
>>
>>May be, you can do some stress analysis using finite element software and
>>by trial and error putting some expansion loop or and anchor at some
>>location to find the best arrangement.
>>
>>Arief
>>
>>-----Original Message-----
>> From: PipingDesign@yahoogroups.com [mailto:PipingDesign@yahoogroups.com]
>> On Behalf Of kuralenthi
>>Sent: July 4, 2005 6:00 PM
>>To: PipingDesign@yahoogroups.com
>>Subject: Re: [PipingDesign] cross country pipe line routing
>>
>>IS it not a buried pipeline
>>
>>kural
>>--- amarendra kumar <amarkr_2302@rediffmail.com>
>>wrote:
>>
>>
>>---------------------------------
>> Hello all,
>>
>>I want to know what problems will arise if for a cross
>>country pipe line ( approx 6 km length op. temp -33
>>deg c -- size 20 inch )one expansion loop is
>>installed just near slope or bend. also what is the
>>ideal locaton of anchors with respect to bends other
>>than that of expansion loop.
>>
>>thanks
>>
>>Amarendra Kumar
>>
>>
>>Regards,
>>Amarendra Kumar,
>>amarkr_2302@rediffmail.com
>>
>>
>>
>>[Non-text portions of this message have been removed]
>>
>>
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>
>
> Regards,
> Amarendra Kumar,
> amarkr_2302@rediffmail.com
>
>
>
> [Non-text portions of this message have been removed]
>
>
>
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Received on Sat Jul 16 10:50:00 2005

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