Thread 2945725

Had to replace the fuel pump in my car, so I thought i might as well tear down the previous one. Picrel.
The second part from the bottom is the impeller. The third part is the rotor. Fourth part are the two brushes.
Yes, mind it is a brushed motor.
Yes, brushed motors arc.
Well, that's ok, because the petrol just flows through the motor . That means no oxygen at the arcing spots. That means no risk of explosion. Right?
What if the tank is almost empty and the pump is pumping a mix of liquid and gases?
Well, that's fine because all the gases inside the tank are actually petrol in the gas phase. Right? So, still no risk of explosion, right?
What if, at this point, someone opens the tank? Air goes inside, right? The pump is pumping gas and liquid, right? Air has oxygen, right?
Still no risk of explosion?

>>2945725 (OP)
>Still no risk of explosion?
Correct. The air-fuel ratio is too rich to support combustion.

TWA800 was just Boeing covering up for (their major customer's) fuckup firing a missile.

>>2945728
Can't tell if you're being sarcastic or not.
I didn't know what TWA800 was, so went and read the wikipedia page.
They say that a combustible fuel-air mixture always exists is fuel tanks

Fuel pumps have been built this way for like 75 years. In that period of time, how many times do you think brush-to-contact arcing has caused an explosion? It's fine.

>>2945734
Have been driving for 30 years now. Now that I know I have a brushed motor inside the fuel tank, can't stop thinking about it every time I start the car

>>2945735
That sounds like a personal problem that you need to get over. The first step in doing so is to stop being a pussy. And that's it. That's the only step.

>>2945738
>stop being a pussy
I have to admit it. I am kind of a pussy sometimes.
This may be one of those times

>>2945733
>They say that
They say that now. But during the process of certification, don't you think anyone ever checked the possible vapor levels before running live wires through the tank?


And then why do they still allow electric fuel pumps and level sensors inside automobile tanks? You don't see them blowing up every day. Or any recalls to fix a hazardous situation.

>>2945733
>They say that a combustible fuel-air mixture always exists is fuel tanks
Aircraft mechanic here. nope.

>>2945735
every car with an in tank fuel pump is brushed.

>>2945725 (OP)
Gas tanks are designed to never allow for the correct air/fuel ratio needed for combustion to occur. This is why a brushed fuel pump can be used.

>>2945725 (OP)
Even if somehow your fuel pump wasn't submerged (it always is, that's why your tank still has gas even after it reads empty) and it somehow sucked in mostly air with some fuel and even if the brushes sparked and ignited the mixture, the flame front wouldn't propagate outside the fuel pump.

There's this concept of a minimum hole size you need for flames to pass through because the surrounding material absorbs too much heat away from the flame. You can wrap an open candle flame in wire mesh and take it into an explosive atmosphere and nothing would happen.

OP thinks his care is going to Apollo 13 itself someday.

>>2945838
Additional nope.
Another acft mech here who's studied and wrenched cars, trucks, motorbikes and machinery for a very long time.

>>2945738
^This. Men regard compulsive behaviors as weakness to be mastered.

I do strongly agree with taking junk machinery apart because that's so
informative. I've done that since childhood.

>>2945739
It is but ignorance is curable with the simple web search OP somehow didn't do.

Search "why don't in-tank fuel injection pumps cause fire?"

There is no excuse for ignorance.

ITT: a bunch of know it alls

>>2947112
found the one idiot!

>>2947650
Found the retard. Your IQ falls somewhere between potato and turd