LPG VAPORIZER RELIEF AT FIRE

[roker]

DEAR ALL,

We have a vertical LPG vaporizer with steam, in the case of fire in order to calculate the flow do we take the vapors produced by the steam at normal operation plus the vapors produced by the heat of the fire or only from the fire since the steam can not give its latent heat and condese because of the fire?

regards,
roker

 

[don1980]

The consensus industry practice is to always consider fire exposure as a stand-alons scenario, never combined with any process upset condition that would make it worse, or better.

That approach has worked for years and there's no movement to change it.

 

[joerd]

Furthermore, the vapors that would be produced by the steam would leave via their normal route if the vaporizer were in operation when the fire started.
Fire is usually considered a "blocked-in" scenario (no feed, no products,) so no credit for vapors leaving, but also no penalty for additional heat input from the steam, just as Don said.

Cheers,
Joerd

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[JoeWong88]

Concept pretty inline with Don & Joerd...

During fire contigency, the process and utility system would be isolated around the incident area or shutdown accroding to plant shutdown and isolation philosophy (normally)...

JoeWong
Chemical & Process Technology

 

[AB6005]

Guys,

In addition to that normal for fire sizing of LPG vessel better dont take any credit factors there by we can be even more safe.what u say ???correct me if wrong.