Dear All,

During internal pressure hydrotest we take advantage of allowable stress = 0.9 * yield stress.

I have one case wehrein jacket chamber MAP is limited by MAEP of inner shell.

now if we do Hydrotest pressure as per UG-99(c) = 1.3*MAEP that inner shell will fail.

Does any body having any reference to increase stress value B from external pressure chart(CS-2) to 0.9*Yield stress for the hydrotest.

Note : Code is silent about external pressure hydrotest.Refer code interpretation : VIII-82-57