Ideally, gas detectors would trigger a shutdown, but more often, they alarm on the panel and operators need to intervene, so it is not a fail safe system.
Thanks for your comments - that is a very reasonable approach. The only other reference that makes me hesitant is API 581 (Risk Based Inspection), which states, under brittle fracture (Section 21.6.3):
Determine the minimum temperature tmin, that the component may be subjected to during...
Sorry, but I am not seeing the connection between my question and the referenced thread. Let's say you have a vessel containing liquid ethylene (BP -155F). If a flange leaks long enough, the flange bolting and possibly adjacent vessel surfaces could approach that temperature. The vessels...
Double tubesheets are used on Hydrofluoric Acid Alkylation unit steam heaters, where cross-contamination from a roll leak would dilute the acid and make it much more corrosive downstream. They normally do not have elaborate leak detection between the tubesheets - just a sealing strip between...
Regarding autorefrigeration, both API 579 and 581 require consideration of the fluid's atmospheric boiling point when estimating the CET, if the vessel contains liquid. In addition to normal and upset operating conditions, does one have to also consider loss of containment - say a flange leak...