Allowable deflection of pipe?

[Redpipe]

HI guys,

Anyone know how to consider allowable deflection of pipe? As I found, it seemed each engineering company have difference value of allowable deflection of pipe for design.

Thanks,

Dave

 

[rconner]

What kind of pipe? What kind of coating and/or lining, if applicable? What kind of deflection (e.g. deflection of the pipe/cross-section as an ovalling ring, or deflection of a length of piping e.g. between supports as a beam etc.)? [Once you provide suitable defining details someone may be able to help you.]

 

[JStephen]

If you have a long span such that you get large deflection, you may also have vibration in the wind- worth checking at least.

 

[Zapster]

Take a look at MSS SP-69

 

[pipingdesigner]

If you just want it to get allowable pipe spans, look at the TOOLS section, sub-section PIPING of

http://www.pipingdesigners.com

for an excel sheet of allowable pipe spans.

http://www.pipingdesigners.com/downloads/pipe span chart.xls

pipingdesigner

http://www.pipingdesigners.com

 

[NormPeterson]

In the power piping industry, 0.1" maximum deadweight deflection at 1500 psi per code sustained stress equation is commonly used for water-filled pipe.


Norm

 

[Cockroach]

Oilfield industry uses deflections consistent with a safety factor of 1.5 to 2.0, given the pipe geometry and understanding of material mechancial properties.

I typically work through the mechanics under full bore load (i.e. maximum pressure testing @ 1.5 MOP) and add the external loads as boundry conditions to the supports.

You can also get similar equations from API reference material. Try pipe supplier websites, they do provide spreadsheet services on the various API equations.

Kenneth J Hueston, PEng
Principal
Sturni-Hueston Engineering Inc
Edmonton, Alberta Canada

 

[StressGuy]

You may find this thread enlightening as well:

http://www.eng-tips.com/viewthread.cfm?qid=152615

Edward L. Klein
Pipe Stress Engineer
Houston, Texas

"All the world is a Spring"

All opinions expressed here are my own and not my company's.