Grass Fire & Vessel Overpressure 1

[Chance17]

I am revalidating safety valves at a rail car unloading facility.
It has four tiers of structure that contains equipment associated with unloading operations.
The facility is isolated. The closest source of flammables is a building 125-ft away.
The liquids being unloaded are absolutely not flammable nor combustible.
All the major equipment have safety valves based on external Fire.
The only credible external Fire I see is a grass Fire.
The classical external Fire is a "pool fire". I have also made some evaluations based on "jet fire" exposure.
The current work is neither pool fire nor jet fire.
Is 'grass fire" a credible overpressure scenario?

 

[zdas04]

If I was doing the evaluation that you are doing, I would start with a pool of gasoline twice the surface area of the cars and an assumed fairly small depth and calculate the energy released in burning it. Then I would look at how much grass would be required to release the same energy (a HUGE number) and try to find a credible scenario that could put that much grass in direct contact with the vessel. My guess is that there is no such credibile scenario and the fire case would not be credible.

David