RE: LOCAL STRESSES IN PIPING

From: <Conner>
Date: Tue Feb 05 2008 - 13:46:00 EST

I'm not sure your question can really be answered (without knowing the specific nature of the "saddle pipe support", relative shapes, dimensions and fixed to the pipe or sliding etc., and e.g. all manner of loads that come to bear between the piping and support structure etc.); however, if you are talking about a very simplistic analysis of a weight of pipe that fits a saddle of some axial width pretty well, I think some past research involving steel and ductile iron pipes has indicated there can be a relatively high "localized stress" in the area of saddle supports. Depending again on many factors, the maximum localized stress near a saddle support can occur at different locations e.g. a few degrees above the "saddle tips", or at the bottom/invert of the pipe saddle contact located (axially) slightly off the edge of the saddle etc. Again, it follows that the level of localized stress can generally increase with a reduction in saddle angle e.g. at least from 120 degrees to less, an increase in span, or a reduction in wall thickness etc. More information can be obtained in many references e.g. in the publication "Design of Ductile Iron Pipe on Supports" (and associated references) available for download from portal http://www.dipra.org/ .

Randy Conner, ACIPCO

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From: PipingDesign@yahoogroups.com [mailto:PipingDesign@yahoogroups.com] On Behalf Of alamgeer5798
Sent: Monday, February 04, 2008 12:10 AM To: PipingDesign@yahoogroups.com
Subject: [PipingDesign] LOCAL STRESSES IN PIPING

In case saddle pipe support cannot be installed, the line shall be analyzed for localized stresses.
What are the local stresses in Piping? and how these stresses are calculated?

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[Non-text portions of this message have been removed] Received on Tue Feb 05 13:46:00 2008