Dear Colleagues

Pressure vessels may contain materials (either gases or liquids) which may be calssified as extremely dangerous to human health or environment or both, however, the implications on such materials on the design and selection of construction materials for the pressure vessels containing these materials are not very clear; it depends how you designate the toxicity of these materials and when you take the last step to designate the service as "lethal". No concencus is known as yet when and how and at what content of these dangerous materials the service should be considered lethal (by "lethal" service it meant to show this word on the nameplate of the pressure vessel). One famous construction code that touches this subject is ASME Sec VIII. More to the point, piping and fittings are also impacted and the de facto of the construction code is so diversified.
your contribution to this thread will improve our knowledge about the subject.