I gotta tell ya, I have great respect for fuel vapors. The flash-point of gasoline and jet fuel is so low that any kind of static electricity can ignite them. I have experience with this. I was stationed in Germany. As the Support Platoon Leader, I was repsonsible for my aviation battalion's ammo and fuel. By regulation, we were required to sample our fuel monthly, in order to perform water and sediment checks. My seargent disconnected a sample hose and we had two 5000 gallon (approx 19000 litres, each) tank trucks go up in smoke. We got the fire out before any explosion, thank heavens.
