How do fuel/water separators work?

[fishingdan]

I have one on my boat, but I don't know how these work. Can anyone describe this for me?<br /><br />Thanks,<br />Dan

 

[Laddies]

Re: How do fuel/water separators work?

Most are micronite paper that won't let water thru, some early ones could not be used on outboards as they would not let some types of oil thru and some use a paper element with a sediment bulb on the bottom

 

[Mark42]

Re: How do fuel/water separators work?

The housings are also generally designed so that the fuel velocity slows way down once it enters the filter bowl. When the velocity slows, gravity has an easy time of letting the water drop to the bottom of the filter bowl. Generally clear bowls have a drain valve in the bottom so its easy to drain water as you see it collecting. <br /><br />Many filters use the micro filter paper that blocks water molecules, many do not and just rely on gravity to sort it out. The micro filter paper is good for removing minute amounts of water that may be in suspension in the fuel. The small Racor unit I just installed utilizes both methods to prevent water from passing through. So far I don't see any water, and that (I think) is a good sign!

 

[dingbat]

Re: How do fuel/water separators work?

The fuel filter assembly for filtering and removing water from a fuel under pressure includes an outer housing, an inner sleeve member, an annular space between the outer housing and the inner sleeve member, and filtering means for filtering the fuel. The filtering means is positioned within the sleeve member. The fuel inlet is at the upper end of the outer housing and provides fluid flow between the outer housing and the inner sleeve. The fuel inlet and annular space are positioned and dimensioned to provide a downward, non-circumferential, substantially laminar flow in the annular space. The inner sleeve member extends downwardly to a position below the bottom of the filtering means. The downwardly flowing fuel and contaminants must turn 180 degrees and flow upward through the filter media to the outlet. The slow moving denser components settle out in the accumulation chamber. The accumulation chamber is the region within the lower end of the outer housing, below the filter media and the annular sleeve. The outlet valve provides a fluid drain for materials which accumulate in the accumulation chamber. The filtering means can be a hydrophobic filter media that prohibits the passage of water through the filter media.