Does any know the main difference between current editions and 1965 ed for ASME BPVC code. What my concenrs are the header thickness calculation for SA-106 material, including the formula, allowable stress, ligament eff., etc.

Dear Samuel,

The factor on tensile stress to the best of my knowledge was 4 until 1999 when it was changed to 3.5. So more than likely the stresses for most materials would be similar to what they were in pre 1999 editions of the Code. Since I have only been at this for 14 years, I cannot comment on those older editions of the Code.

Hopefully, some others that are active in the forum can lend their knowledge in reference to the 1965 edition.

It appears that no Sec II at that time, and what I got for MAS attached to Sec VIII 1965 Ed was significantly different with the pre-1999 Sec II. Any more comments?

Hello Samuel

Prior to the 1992 edition of ASME VIII Divisions 1 and 2, the design stress values 'S' were included in the main body of the codes. In 1992, a new code section ASME II Part D was introduced wherein the stress were moved from the Section VIII codes to the new code, including the external pressure charts.

Sometimes, an older version of the code becomes available through organisations such as E-Bay, and these older editions would give historically relevant information.