Hi,
Please any one clarify me, Thank you for reply.

ASME 31.3 code says.
Material A335 P11
Temp: 850 deg F
Sy: 206843 KPa. = 30 Ksi (Yield)
Tensile 60 Ksi = 413685 KPa

but in my Stress summary shows.
CodeStress Ratio (%): 99.6 @Node 3948
Code Stress: 255787.5 Allowable: 256749.2

Allowable stress 9256749.2) should be less then Sy: 206843 right why here its more. Is there any thing wrong, the way I am looking numbers.

allowable stress (256749.2)

Is your code stress a sustained or expansion?

In expansion case it is Code Stress: 255787.5 Allowable: 256749.2
In SUS case it is CodeStress Ratio (%): 71.8 @Node 6990
Code Stress: 70060.2 Allowable: 97629.7

I should let Ed finish his conversation as he's on the right track. But...

You assume that yield is the limit for the expansion stress range. It is not.

The limit for the expansion stress range is set by the piping code. Check B31.3 or see what we have listed in the Quick Reference Guide.

I think that this kind of questions are not very inspired. Because you blame Caesar II for some things you do not understand.

Caesar do what Caesar do. Mean what is wright to do.

Indeed, it is what I suspected. The allowable for expansion stresses is not the yield stress. You need to take a look at section 302.3.5 of B31.3 to understand the limits for the different classes of stresses.