Actually I was put under same problem. Thank you for your valuable guidance Dr. Saha, Pankaj and Rajesh.
Regards,
Rajesh.Balapure@ril.com09/24/03 11:44 AM
Please respond to PipingDesign
"Normally, for reputed pipe support suppliers like Lisega, we do not
question
their catalogue values. In case a vendor do not comply to their catalogue
values, well, I believe you have selected the wrong vendor."
As you may be surprised if you know the vendor, the name is not disclosed.
However it was sort of a quiz to the vendor who had ignored the fundamental
principles (Euler's buckling loads, Load follower effects, large deflection
analysis etc.) Good that you have described some of them to some extent.
I feel it was a casual approach of the vendor which led to such unnecessary
confusion. The same struts as supplied by the vendor are in operation
almost throughout the world.
Ofcourse the onus of use of the struts as piping support rests solely on
the pipe stress engineer who is well conversant with compression member
design.
.Rajesh V Balapure
Mandal Pankaj
SPEL-T1 To: "'PipingDesign@yahoogroups.com'"
<Pankaj.Mandal@si <PipingDesign@yahoogroups.com>
emens.com> cc: (bcc: Rajesh V Balapure/JAMNAGAR/RIL)
Subject: RE: [PipingDesign] Strut
09/24/2003 11:27 Importance: Normal Sender's OU: Reliance |------------------|
AM | [ ] Confidential |
Please respond to |------------------|
PipingDesign
A rod, in general, behaves better in tension than in compression. For
example, pipe hangers (using tie-rods) are used as tension members only
(and
never in compression) solely because of its slenderness (l/r ratio). In
case
of a strut, we have the advantage of lower slenderness ratio due to the
inherent construction of the element (larger diameter). Hence we use it for
compressive load too. However, for a fixed diameter, as length increases,
the slenderness ratio also increases and, as a result, the load carrying
capacity decreases with increase in strut length.
A table for the same is already available in pipe support catalogue of
reputed companies like LISEGA.
Normally, for reputed pipe support suppliers like Lisega, we do not
question
their catalogue values. In case a vendor do not comply to their catalogue
values, well, I believe you have selected the wrong vendor.
Regards,
Pankaj Mandal.
Siemens Power Engineering Pvt. Ltd.
Plot-6A, Sector - 18,
Maruti industrial area,
Gurgaon - 122015.
India.
Ph. - (0091) 124 2347990 extn.1616
Fax - (0091) 124 2347512 - 14
E-Mail - Pankaj.Mandal@siemens.com <mailto:Pankaj.Mandal@siemens.com> .
-----Original Message-----
From: Rajesh.Balapure@ril.com [mailto:Rajesh.Balapure@ril.com]
Sent: 24 September 2003 10:53
To: PipingDesign@yahoogroups.com
Subject: Re: [PipingDesign] Strut
SubrataP Saha
To: Rajesh V
Balapure/JAMNAGAR/RIL@Reliance
09/24/2003 10:45 cc:
AM Subject: Re: [PipingDesign]
Strut
Importance: Normal Sender's OU:
Reliance |------------------|
| [ ] Confidential |
|------------------|
SubrataP Saha
To:
PipingDesign@yahoogroups.com
09/24/2003 10:44 cc:
AM Subject: Re: [PipingDesign]
Strut
I would like to share an interesting interaction will a reputed vendor on
piping struts about an year back.(the name I do not wish to disclose for
obvious reasons).
With regard to the straight forward question as to whether the load
capacities as mentioned in their catalogue is valid for both tension and
compression, a prompt reply came that they are applicable in both
directions. Subsequently a follow up query on a theoritical case whether
a 3m long strut can behave like a shoe support if connected from bottom was
put to them. This time the reply was not forthcoming and after followup we
came to know that the matter was being discusssed by the specialists. But
the final decision has not yet arrived and the catalogue values remain
same.
I will leave at this stage and hope the group can very well figure out the
reply on the basis of sound engineering judgement and not specious
arguments.
Regards
S.Saha
FDC - Piping
Reliance Refinery
Jamnagar
India
[Non-text portions of this message have been removed] Received on Wed Sep 24 06:58:00 2003
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