Hi Bom,

if Both the temperature(from -50deg c to 250 deg c) happends in a single cycle, it is better to consider the complete stress range( ie sum of exp range from max temp to ambient and minimum temp to ambient).And indiviudal stress range also will be checked( max to ambient/ min to amb)seperately.

Apart from that I have a clarification.This case( ie from -50 to 250) will not happend regularly( it means that like normal cycle). Hence , Can we take the stress range factor "f" as the maximum of 1.2(refer ASME B31.3 page 16 FIG 302.3.5.)?So that the total stress range will be checked with SA=1.2(1.25Sc+.25Sh)

The coade does not say about this, it seems.

I request any one can explore this clarification.

regards

Sha..