Hello !
How are you and nice to meet you thru forum.

I have a question concerning above subject.

ASME B31.3 Para. 302.3.5, foot note 6 for basic allowable stress(Sc, Sh) i.e,
"For castings, the basic allowable stress shall be multiplied by the applicable casting quality factor, Ec
For longitudinal welds, the basic allowable stress need not be multiplied by the weld quality factor, Ej"

Could anybody explain the reason why the basic allowable stress need not be multiplied by the weld quality factor, Ej


Thanks and regards,

Michael

The refernce to footnote 6 is in definition of Sc and Sh with regard to displacement stresses. Longitudinal welds are not generally affected too much by displacement cycles which are dominated by bending, whereas they are by directly loaded by pressure. Castings on the other hand are affected by loading in any direction, including longitudinal, circumferential and bending ... thus Ec is required ,and Ej is not, for displacement stresses.

Dear MoverZ,

Thank you for your useful and kind reply.

Regards,