Difference in allowable stress
Difference in allowable stress
(OP)
In CAESAR, When activating allowable stress under B31.1, the value for A53 B is SC=15000psi.
I checked B31.1 2007, which says in table A-1, that the allowable for A53 B is 17.1 ksi up to 650degF.
I could not figure out why the difference. Please advise me.
Thanks
I checked B31.1 2007, which says in table A-1, that the allowable for A53 B is 17.1 ksi up to 650degF.
I could not figure out why the difference. Please advise me.
Thanks
It boils down to simple math.





RE: Difference in allowable stress
My version 5.1 of CaesarII shows SC = 17,100 psi for A53 B.
I think you need to get the latest update from COADE website which has 080512 build.
Some are aware of the ASME Sec I change from 4:1 design factor to a slightly more reasonable 3.5:1 design factor. Of course the ASME B31.3 has used 3:1 design factor all along. There was some incentive for the ASME designs to be more competitive with vessel designs to other international codes, hence the design factor being changed. The revised allowables, revised hydrotest pressure factors, etc. are finally working its way through all the documentation and software updates.
RE: Difference in allowable stress
Richard Ay
COADE, Inc.