I have noticed that there are two options for B31.1 code, existing one and 1967 Ed. What is the main differences between them? Why 1967 Ed?

CAESAR II is updated to utilize the rules from the most recent edition and addenda of the piping codes. We do not maintain old codes except for that 1967 Edition of the power code. At the time, the '67 code looked a lot like B31.3. It was the following Edition of that code introduced major changes that make it work more like it is today. Back then, the codes didn't change as fast as we see today and there were still a demand for the older code. Piping programs of the day maintained the 1967 code for those users who wanted it. (My Dynaflex manual of 1979 states that B31.1-1967 Ed. is applied if no piping code is specified.) CAESAR II mimicked that choice even though few, if any, users cared anymore.

It should be noted that ASME BPVC Sec I had changed the allowable stress for SA335P11 significantly, in 1968 edition. It was reduced for high temperature applications, and the allowable stresses at 1000 Deg F and 1050 Deg F were reduced 16% and 26%, respectively. Since no Part D of Sec II available at that time, I do not know the situations for other codes, such as Sec VIII and B31.1. However, in my personnel opinion, COADE should try to confirm if those remarkedly changes, if existed for B31.1, have been reflected by your CAESAR II, as you had introduced the pre-1968 code to it.

The answer to your question is "no".

CAESAR II introduced its material database in Version 3.24 (March 1997). We used the material data availalbe at that time for (the piping codes current at that time) for the database. Since then, as the codes have updated their material properties, we have revised the material database.

If you want to use a material we don't have in the database, or you want to use properties from an older edition of a code, you can add a new entry to the database, or manually override the properties in the input file.

The CAESAR II material database doesn't have any materials for the 1967 edition of the B31.1 code.