Does anyone know anything about Hydraulics? Specifically how a gas pump could fail to shut down. I am writting a horror novel and this one character dies from being incinerated by the fuel that spilled. However this can not be just a bit of overflow. It all comes together from too much pressure in the lines which I can explain away. What I cannot explain is why the pump did not shut off I know it has something to do with something called a venturi tube which uses suction to tell where the liquid level is in the tank. what I need to know is where a second hole should be placed on that tube to get it to flow freely. either higher or lower than the original hole. I am thinking higher. because if you stick a straw in water with holes all the way up, it will fail to draw suction until the highest hole is covered. Which is how a venturi tube works. once it starts drawing suction, it cuts off the pump. I am sorry for the long winded explanation, but your replies are all welcome.
There's a breakaway valve in the automatic shutoff fuel nozzle. If a piece of grit or something gets in there preventing the valve from closing, well, your character might get fuel all over him. You don't have to make it as complicated as a problem with the venturi tube. You're writing a horror novel; I assume your baddie can arrange to sabotage the breakaway valve.