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.