Fuel tank strainer,screen?

[modela4shane]

What was the reason for a screen in the fuel tank filler neck on the Model A? The service bulletins on page 311 say the screen is not a strainer but a fire preventative device. How does the screen prevent a fire if fuel vapor can escape thru the strainer? Did it stop static electricity when the fuel pump nozzle touched the strainer during a fill up?

[Model A Ron]

I think it's called a spark arrester and i always wonder the same as you. To the best of my knowledge it only stops you from hitting the float when filling with gas.

[bruceincam]

The spark arrestor works by exposing any flame to a large number of small surfaces (the screen). A flame front exposed to such a device will get broken up by the screen and as a result cool to below the ignition point and become self extinguishing. In theory at least ----

If you want a better explanation, just search for "spark arrester" and read on --------

Now, full disclosure, I've removed mine because of the difficulties it offers in refueling at the service station. It's hard enough to lean over the fenders and the cowl.

[Model A Ron]

Originally Posted by bruceincam

The spark arrestor works by exposing any flame to a large number of small surfaces (the screen). A flame front exposed to such a device will get broken up by the screen and as a result cool to below the ignition point and become self extinguishing. In theory at least ----

If you want a better explanation, just search for "spark arrester" and read on --------

Now, full disclosure, I've removed mine because of the difficulties it offers in refueling at the service station. It's hard enough to lean over the fenders and the cowl.

My 29 Phaeton came to me without one and since I look down into the tank when filling I never put one in.

[Stingray70]

If you guys want to be precise, that is technically a FLAME ARRESTOR, not a SPARK ARRESTOR. Spark arrestors are typically found in exhaust systems to prevent hot particles (carbon) from passing through while allowing gasses to flow. A flame arrestor is typically used on fuel storage systems.

In our Model As, that screen (in theory) would prevent fire caused by static discharge during fueling from entering the tank causing an explosion.

I am guessing that long ago something bad happened to a few people prompting Ford to add that device. With or without the flame arrestor, if one keeps the fueling nozzle in contact with the tank, static discharge shouldn't be an issue.

[WHN]

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Originally Posted by Stingray70

If you guys want to be precise, that is technically a FLAME ARRESTOR, not a SPARK ARRESTOR. Spark arrestors are typically found in exhaust systems to prevent hot particles (carbon) from passing through while allowing gasses to flow. A flame arrestor is typically used on fuel storage systems.

In our Model As, that screen (in theory) would prevent fire caused by static discharge during fueling from entering the tank causing an explosion.

I am guessing that long ago something bad happened to a few people prompting Ford to add that device. With or without the flame arrestor, if one keeps the fueling nozzle in contact with the tank, static discharge shouldn't be an issue.

If you don’t have one installed in your car get one!

We can argue whether it is needed until the cows come home, but “WHY” take any chances.

Better safe than sorry.

Enjoy.

[Ramman]

I'm with WHN on this one. Look at the pump for all the warnings NOT to have a gas can setting in your trunk or truck bed. Place on the ground, and they're 90% plastic.
I view a Model A as filling an elevated metal container sitting on 4 rubber insulators. Plus have you ever heard of Mr. Ford spending a nickel he didn't have to?

[Stingray70]

Originally Posted by Ramman

I'm with WHN on this one. Look at the pump for all the warnings NOT to have a gas can setting in your trunk or truck bed. Place on the ground, and they're 90% plastic.
I view a Model A as filling an elevated metal container sitting on 4 rubber insulators. Plus have you ever heard of Mr. Ford spending a nickel he didn't have to?

I agree completely with you guys. I have one in my car. I do believe that properly grounding the nozzle is even more important. BTW you can get a static discharge improperly fueling a plastic container just as easily as a metal one.

[Model A Ron]

Interesting point.....maybe I should pick one up.

[JayJay]

I had to remove mine for a different reason. Somewhere along the line it looks like the arm on my fuel gauge was replaced, and the replacement arm is just a hair shorter so that it hangs up on the flame arrestor. I will ultimately fix that and reinstall the arrestor but in the meantime I had to remove the arrestor to make the fuel gauge work,

JayJay

[Brokenvette]

That is why you hook up a ground wire to the plane at airports when fueling with avgas. Static discharge.

[Oldgearz]

So why don't regular cars and pickups blow up when fueling???? Just be careful in what you are doing and forget about it. I guess we all have fueled gas tanks thousands of times----I ain't blown up yet!

[AzBob]

Originally Posted by Oldgearz

So why don't regular cars and pickups blow up when fueling???? Just be careful in what you are doing and forget about it. I guess we all have fueled gas tanks thousands of times----I ain't blown up yet!

X2 here as well. Growing up on a farm with with tractors that had the gas tanks directly above the engine, None of them had flame arrester screens and none of them caught fire and blew up.

My '29 tudor had a screen. My '30 sport coupe came to me without and will remain without.

[GPierce]

Fuel hoses at gas station have a ground wire running thru them as do the hoses sold for fueling farm and construction equipment. The avgas hose on my truck bed mounted fuel tank has a ground wire running thru it.
My guess I’d that was not the case in the 20’s and 30’s so they used the flame arrester.

[TomInCologne]

Originally Posted by Oldgearz

So why don't regular cars and pickups blow up when fueling???? Just be careful in what you are doing and forget about it. I guess we all have fueled gas tanks thousands of times----I ain't blown up yet!

You remember when Opel/Vauxhalls started to catch fire when fuelled? Cause was a loss of ground connection to the filler tube.


This topic is part of my everyday professional life and yes, these strainers are called flame arrestors. I wouldn't go without one...

[duke36]

There are screw in and drop in types. Ford initially used the screw in type, then drop in with tabs, and then in '31 went back to the screw in type. One can adapt the drop in type for the later style to be be free pulled out if needed. The vendors offer extensions that help with leaving the screens installed when using modern gas pump nozzles.

[Fullraceflathead]

You shouldn't have any trouble filling up your gas tank with a modern nozzle as long as you control the fuel flow to 1 of the slower settings by just squeezing the handle enough to initiate fuel flow.