I might be wrong, but S=PD/2t is the circumferential stress due to pressure (hoop stress).
The longitudinal stress produced by pressure is S=PD/4t, thus half of hoop stress. This equation is valid for a long cylinder with ends caps, somewhat conservative for normal piping. As far as I know, for full restrained pipes (as buried pipelines) is not usual to consider the pressure load to calculate the total longitudinal stress.
Lemos Pinto
> >The Longitudinal stress value is SL=P*D/2*t
> That's for presure only. Thermal, wind, seismic and gravity load also
> produce longitudinal stress. So does water hammer.
>
> Christopher Wright P.E. |"They couldn't hit an elephant from
> chrisw@skypoint.com | this distance" (last words of Gen.
> ___________________________| John Sedgwick, Spotsylvania 1864)
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Received on Wed Aug 29 19:16:00 2001
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