Re: AW: Limit stop in Piping stress analysis

From: <Mukesh>
Date: Fri Apr 19 2002 - 10:43:00 EDT

Dear Ashok,

Let's go back to basics..

stress is directly proportional to strain and

strain = change in length / original length..

Lets say if original length is 1 mt. and change in length is 2 mm for a particular material at particular temp. Then if the length is 2 mt. it will be 4 mm and so on...so the strain is independent of the length. And breaking the length will not achieve and distribution of load on the straight run. Rather the case will be if you are putting one sided constraints then only one of them will work and if you are putting two sided constraints then each constraint will be over-stressed (of course depending on the temperature).
So it is advisable to put only one axial constraint in a straight run and it's location on the straight run will govern the expansion transfer which is to be absorbed in the adjacent legs.

I hope this will help.

Best Regards,
Mukesh Chugh

<tt>

Man,<BR>
<BR>

What are you upto. Any way, just to remind you that the golden rule in<BR>
piping analysis is to provide only one limit stop (or axial stop) in a<BR>
straight pipe run unless you have an expansion loop in between. In your<BR>
analysis please check if the line is balanced in expansion sress. In my<BR>
opinion the line is already overstressed.<BR>
<BR>

I am unable to understand your &quot;distribution of piping loads&quot; concept. In<BR>
any case if the line is hot and there is a long straight run, try using an<BR>
expansion loop with two limit stop at suitable positions on either side.<BR>
<BR>

Regards,<BR>
Pankaj Mandal<BR>
Siemens Power Engineering Pvt.Ltd.<BR>
Plot 6A, Sector-18,<BR>
Maruti Industrial Area,<BR>
Gurgaon-122 015.<BR>
<BR>

ph:0091 124 6347990 Fax: 0091 124 6349050<BR> Mail to Pankaj.Mandal@siemens.com<BR>
<BR>
<BR>

-----Ursprüngliche Nachricht-----<BR> Von: Ashok Dani
[mailto:ashokdani@tatachem.tata.com]<BR> Gesendet am: 19 April 2002 08:19<BR>
An: 'pipingdesign@yahoogroups.com'<BR>
Betreff: [PipingDesign] Limit stop in Piping stress analysis<BR>
Wichtigkeit: Hoch<BR>
<BR>

In a straight pipe run how many limit stops we can provide. <BR>
<BR>

I have designed test model wherein I have put three limit(axial) stops(with<BR>
equal and unequal gaps) in straight run to distribute load on three supports<BR>
but in operating case last axial stop is acting while other two stops are<BR>
not acting during operating case. <BR>
What would be the reason for this phenomena?<BR> Thanks<BR>
Hitesh<BR>
<BR>
<BR>

_____________________________________________________<BR>
Unsubscribe: PipingDesign-unsubscribe@yahoogroups.com
<BR>
<BR>

Your use of Yahoo! Groups is subject to <a href="http://docs.yahoo.com/info/terms/">http://docs.yahoo.com/info/terms/</a>
<BR>
<BR>
</tt>

<br>
<tt>

_____________________________________________________<BR>
Unsubscribe:
PipingDesign-unsubscribe@yahoogroups.com</tt>
<br>

<br>
<tt>Your use of Yahoo! Groups is subject to the <a
href="http://docs.yahoo.com/info/terms/">Yahoo! Terms of Service</a>.</tt>
</br>

</body></html>



For live cricket scores download Yahoo! Score Tracker   at: http://in.sports.yahoo.com/cricket/tracker.html Received on Fri Apr 19 10:43:00 2002

This archive was generated by hypermail 2.1.8 : Mon Oct 27 2008 - 20:23:56 EDT