I am modeling a number of vessels constructed from an old material (BS14: 1942)using PD5500 and cannot undertand how the ambient allowable stresses are calculated.

I have the 2000 version of the code here which states that fe = the smaller of Re/1.5 or Rm/2.35. I have input the appropriate Ultimate Tensile and Yield stresses into the new materials database along with allowable stresses at 50 and 100 degrees C (calculated according to the above equations) and the yield at the same temperatures.

However when I use the material at ambient temperatures, the allowable stress is closer to Re/3. Have I mis-interpreted the code? Has the code changed dramatically since 2000, or am I not using the software correctly?

Stodd.

i forgot to mention that I am using PVElite 2008 May build.

Stodd,

Check this previous post. It may be relevant. A quick may of checking is to try 51°C

http://www.coade.com/ubbthreads/ubbthreads.php?ubb=showflat&Number=19428&page=13#Post19428