I'm About to embark on the analysis of a 10"
CS Glass Lined Pressure relief piping system

Normally under partial vacuum, but can experience
6.6barg @-29/200c.

Bellows/Graphite condensers prevelent.

Any Pointers from you guys?

Ive asked Pfaudler for the allowables on the Pipework, but they seem to be puzzled as to why i am asking.