Hello All,

Can somebody will expain who can I calculate the torsional moment
in B31.3 Para. 319.4.3

Your help will be appreciated

Albert Avidor
Ontario/Canada
albert.avidor@invista.com

There is no particular reference to torsional moment in (2006 ed.) 319.4.3.

Torsional moment at any given point in a piping system, or any other structural device is a function of the geometry and loads. There is no governing equation for this.

Hello Albert,

All the forces and moments at each node are calculated by Caesar II. The torsional moment is the moment about the centerline of the pipe (as illustrated in B31.3, Figures 319.4.4A and 319.4.4B. In B31.3, Paragraph 319.4.4, equation 17 (with references to equations 18, 19 and 20), the bending and torsional moments are used to calculate the Flexibility Stress. You should refer to B31.3, Code Case 178 for the equations used for combining forces and moments to determine longitudinal stresses due to sustained weight and pressure.

Regards, John

THANK you
Albert