BH06L3:
I would not agree with the statement above as I have flooded the engine can doing a A/F fuel filter drain. Throttle was left full open and when boost pumps and Battery where turned on fuel started spewing out the engine drain valve......
BH06L3 is a little confused. In a RR-250, the engine-driven fuel pump is what they call a "positive displacement pump." That is, if it stops, the boost pumps *cannot* push fuel through it. If the engine-driven pump stops (shaft shears, say), the engine WILL quit from fuel starvation.
Conversely, with the engine shut down there is no way that fuel can make it past the engine-driven fuel pump to the fuel control and then to the nozzle screwed into the burner can.
The drain valve on the airframe fuel filter on the engine deck is *before* fuel gets to the engine-driven fuel pump and fuel control. In the case BH06L3 cites, the result would have been the same whether the "throttle" was opened or closed. If the battery is on and the A/F fuel filter drain is left open, boost pump pressure will cause fuel to spew out if the fuel shut-off is open. But no fuel will go through the engine.
You cannot "flood" a turbine engine if it is not running. Fuel
will not get past a non-rotating engine-driven fuel pump.