Project for electro gurus- water seperator indicator

[Techno]

I was thinking that if you have a water seperator it would be nice for something to tell you to dump it.
Although I don't think they seperate water this is mostly a matter of semantics, water does collect here and indicates a water problem. I think it indicates a water problem but doesn't remove it.( my opinion)
Maybe a conductivity thing that would read a water presence. A float might work but would need more skilled modification.
Light detector type thing? Light emitter/detector.
How ever it worked it would be most effective before you started up and indicate a water presence in this part of the fuel system. Turn the key on before you trailer to the water and it alarms, dump now and check the tank.
Since the water collects here it only makes sense that there should be an indicator here to tell to dump it. The seperator seems like half a system.
I'm thinking of the spin on aftermarket type.

Fuel weighs about 6.6 lbs per gallon and water 8
The Optical refraction should also be different, as should the conductivity 3 methods I can think of for detecting it.

[us1]

Take the water sensor and module out of a stock motor and figure out how to use it on an after market model.

[VectorPat]

Doesnt Racor make a water sensor? Like this...
http://www.parker.com/parkersql/default.asp?type=2&id=27

[insptech]

There are bilge pump switches that will pump water but not fuel, they use some type of capacitance or resistance circuit.

[ShorePounder]

If I'm not mistaken, Hydrocarbons don't conduct electricity.

[pyro]

Shorepounder is exactly right, and that's how the stock separator works. Fuel by itself does not conduct electricity. Even something as simple as a pair of contacts 1/8" apart in a fuel line could be used to detect small bursts of water coming through the fuel system.

[Techno]

Water also doesn't conduct. It has a dielectric strength of 50 Kv at 1 mill. It's the contaminates in it that make it conductive. Unless it got a contaminate from the oil or gas it would still be "pure"

I guess theres only one thing to do and put a multi meter in a mix.

[CompKing]

The early 90's Dodge Cummins have a spin on fuel filter with a simple screw in water sensor in the bottom,It was just 2 probes and 2 wires so ya might look at one of them.

[pyro]

Techno is actually right, but this only applies to pure distilled water. Anything in real-life is always going to have some salts in it to make it at least mildly conductive.

Personal experiences have showed that the separator does separate water from fuel, and the alarm works as it's supposed to. Controlled tests have also showed that water can still pass through the separator under certain conditions. In addition to merc's separator and sensor module, an additional detector that can sense short bursts, even drops of water coming through the fuel line, would be ideal for a warning system.

[Techno]

The only kind of water I know of that can get into gas is distilled water. Condensed in some tank. I don't think it's pure though, it's gotta be yanking something out of the gas.

[schematic]

Racor does sell the module to detect water using 2 probes drilled into the sediment bowl. It would be easy to build one as well. I could supply a diagram I use to build w/w fluid monitors. Same stuff....

[Jeff_G]

Who told y'all fuel doesn't conduct electricity? Better go back to school.
Hydrocarbons by themselves are not. Some chemical compounds, read fuel, are highly conductive. Fuel is NOT pure hydrocarbon elements. Compounds containing oxygen are usually conductive. Water is highly conductive. This is the basic principal of the fuel testers we use to detect illegal substances in fuel in racing. We are testing the reletive conductivity of the chemical compound, read fuel, oil.
That is also the principal behind the water fuel seperators that do have alarms etc. Most diesel motors have a water seperator and most come with a sender to an alarm.
Rapair has a gearcase detector for OMC and Yamaha that does the same thing.