Dear members
I have a Vessel 2ft x 4 ft which is used to prevent the overfilling of a LNG truck when the pump fils in -pump capacity - 200 gpm and dp gr -0.425.
The vessel is like a stopper to prevent liquid going into a BOG Header line going to BOG heater.
1. psv case -overfilling
2. Fire case
Truck overfilling - considered the pump capacity
Fire case - This is where I am confused,
Is it the BOG coming back/to BOG heater to the vessel which is a vapor flow
or is it the flash vapor from the truck overfilling liquid to vessel -liquid flow
Please guide
Attached is the sketch