I don't have a dedicated separator, just the aftermarket Fram, which is just a filter. Better put a Racor separator on my shopping list, then?
Actually, I'm not sure of the capabilities of the Fram. It does have a drain screw, but the bowl is not transparent. It takes a C1110PL cartridge. Does anyone know if it separates water?
filters (installed with the filter bowl 'lower' than the filter 'head') will trap water, including the spin on type. . For 'best' water 'knock out' you should have such mounted in the 'very' lowest portion
of the entire fuel delivery system ... so that water that 'drops out' from the fuel will drain towards the 'filter'. A cartridge type filter housing (with 'bowl down') with NO filter element installed will trap water.
For non-transparent bowls with drain plugs, either routinely drain them or put a '**** valve' in place of the drain, .... or (against boat and CG regs.) put a small length of fuel compatible clear hose ('translucent teflon-type' is best) between the drain port and terminate the 'tubing' to a **** valve.
If you need to trap air, simply install the filter with the bowl higher than the filter 'head' and put this in the highest portion
of the entire fuel delivery line.
FWIW ... if you notice that there is water in a bowl, it means that
1. your fuel is totally 'saturated' with water vapor (usually 'old' fuel, or from a fuel tank that is continually 'topped off');
2. your fuel source is delivering 'old' fuel + water;
3. your deck fill is leaking.
The importance of guarding against free water in the fuel delivery system (besides the fact that water doesnt 'burn' very well) is that water hitting the hot injector tips can shatter them.
4. If you do see
'water' in your filter bowl be aware that the typical filter 'cellulosic' material, even that it is 'resinated' with epoxy compounds, will 'soften' and become weakened ... and you should consider to 'change out' that filter cartridge between 6-12 months and regardless if there is 'dirt' captured on it or not.
How to prevent water in fuel.
1. dont always top-off
the tank, especially with a 'large' tank.
2. keep the MINIMUM amount of fuel in the tank to cover your immediate needs, plus some reserve.
3. Drain/empty the tank completely for loooooong layup/storage.
4. Buy your fuel only from a high-turnover source - a fuel source that caters to 'watermen' or a large fishing fleet .... or jug it in from a 'truck stop' --- "Fresh" fuel !!!!!
5. Routinely change the O-ring in your deck fill cap.