Wiring In The Fuel Tank!

[Sandro Seminara]

I had to replace my fuel pump today and was very simple, but here's what I don't understand... There's a bunch of exposed wiring on the fuel pump assembly, I would think you'd want all that sealed. Do those connectors sit in gas at any time? I mean I would think anything electrical exposed to gas liquid or vapor would cause an explosion. Any one know why it doesn't?

Regards

Sandro

[MrWinkey]

because they are on opposite sides of the pump. now that you realize this. that was my biggest issue with the flight 800 story which I still don't believe. :(

[Sandro Seminara]

I see a link to Saab, you know anything about exhaust systems for them. I had some questions on a 97 9000 Aero.

[Ihatespeedbumps]

The wires are submersed in gas every time you fill up the tank. I hope that they would have though through the exposed wires thing when they designed the car, I guess that's why I never put much thought into it :P

[Ozark Lee]

Any one know why it doesn't?

In its liquid state gasoline is very stable. When I was a dumb jerk kid (as opposed to the dumb jerk parent that I am now) I worked at a Vickers gas station. We kept a 1 gallon pail of pump regular around to toss our cigarettes into - lit. With an open flame it would have blown up in a heartbeat but the gas always extinguished the lit cigarette.

There were thousands of attempts by me and my idiot co-workers to prove the theory wrong and none of them ever worked.

The wiring on the fuel pump on my Suburban actually melted the insulation completely off of the wires on its first fuel pump failure but the car didn't blow up - fortunately I had just filled the tank so it was completely submerged in the liquid gasoline and not the vapors.

It all comes down to the flash point.

...Lee

[Serge]

Additionally, the EVAP system picks up all the vapors that would have otherwise been at the top of the tank.

[PHLY50]

Any one know why it doesn't?

For gasoline fuel, the stoichiometric air/fuel mixture is approximately 14.7 times the mass of air to fuel. Any mixture less than 14.7 to 1 is considered to be a rich mixture, so basically there is not enough air (oxygen) within the fuel tank compared with fuel vapour to make an explosive mixture.

Phil.

[Ronny]

For gasoline fuel, the stoichiometric air/fuel mixture is approximately 14.7 times the mass of air to fuel. Any mixture less than 14.7 to 1 is considered to be a rich mixture, so basically there is not enough air (oxygen) within the fuel tank compared with fuel vapour to make an explosive mixture.

Phil.

Well, and there you go. Thank you Phil for that. For the Red Necks, what he means is;

ya ain't gonna get no bang cause thar ain't no air in the gas tank..........

[BEJinFBK]

Watch Mythbusters sometime.

This was one of their topcs.

[matt1122]

It's not just like that in cars, though, that they do this. Apparently it's that way in Jet planes as well. It needs to be like that in order to accurately measure fuel levels, etc. Here's an interesting article about using an alternate to live wires in the fuel tank: http://spectrum.ieee.org/oct05/1863