Fuel Polishing System

[Cap]

Hi All,

I'm looking into building a fuel polishing system for my boat, but I'm not sure what hardware I should use, so I'm hoping someone can give me some adivce. I have a 35 ft. catamaran sail boat with two 13hp Nanni diesel engines. I would like to know what size filter(s) I should be looking at and what size fuel pump to run. Any help would be appreciated.

Thanks...Jeff

[Randal Johnson]

I have one of these filters on my boat and am satisfied with it.
Model F-1

[Mark Johnson]

Really simple... I made mine of an extra Racor 500 fuel filter with a 2 micron element. I have a homemade brass valve "manifold", that choses the "draw from" and "return too" tanks. (I have a pt. and stbd. tank) If you only have one, you don't need this.

After this manifold, I have another. It choses to "run the engine" OR "polish the fuel". If it is on "run", then it goes through another Racor 500 before going to the engine.

If it is on "polish" (and I flip the switch on the small electric fuel transfer pump), then the fuel goes around and around, through the filter, and into the chosen tank, until I switch it off.

If needed, I can even use the system to transfer the fuel from one tank to the other!

By using a Baja filter to fill, always biocide/cetane boost the fuel, and polishing occasionally, I have had NO fuel related problems in 15 years. (Not even in the third world).

Mark

[atoll]

i'v all ways used domestic type water filters and bowl and a shureflow pressure pump with diafram rated for fuel,it can do 3000liters in a few hours.

drill and tap a drain hole in the bottom of the large clear bowl to drain off water and sludge,filters are very cheap and large,works great

[motion30]

I made mine with a holley pump and a very large napa screw on filter It works well but it would be nice to be able to see inside the filter Maybe the racor filter would be better

[sailnautilus]

I would highly recommend looking into the RCI fuel purifier filter.
See them at www.rcitechnologies.com. This is an interesting item and does not require replaceable filters; it uses coalescing plates to separate dirt water and fuel. This is the filter used by most of the "Fuel polishing" companies in south Florida who work on the large commercial boats, the military and coast guard boats and the large sport fishing fleets.
We designed a system using this filter and a cheap 24 volt fuel pump (our boat is 24 volt) and a series of valves. This allows us to filter and polish fuel from tank to tank or back to the same tank.

Has worked superbly and I have a large supply of Racor filters I will never use, as the filters never seem to get dirty once the fuel is filtered on a regular basis.

Also, we have aluminum tanks, so we installed a separate pickup for the filtration system which goes right down to the bottom of the tanks; this was after finding sludge in the tank below the level of the pickup for the engine. Works great!!

Fair winds,
Dr. Michele

[osirissail]

Although there are many options for an external fuel polishing system, built mine somewhat similar to Mark Johnson.
- - I simply added a Walbro Diesel Fuel Pump along with a couple of valves to redirect the pumped fuel from the Racor Filter back into the return line to the diesel tank.

[motion30]

Originally Posted by sailnautilus

I would highly recommend looking into the RCI fuel purifier filter.
See them at www.rcitechnologies.com. This is an interesting item and does not require replaceable filters; it uses coalescing plates to separate dirt water and fuel. This is the filter used by most of the "Fuel polishing" companies in south Florida who work on the large commercial boats, the military and coast guard boats and the large sport fishing fleets.
We designed a system using this filter and a cheap 24 volt fuel pump (our boat is 24 volt) and a series of valves. This allows us to filter and polish fuel from tank to tank or back to the same tank.

Has worked superbly and I have a large supply of Racor filters I will never use, as the filters never seem to get dirty once the fuel is filtered on a regular basis.

Also, we have aluminum tanks, so we installed a separate pickup for the filtration system which goes right down to the bottom of the tanks; this was after finding sludge in the tank below the level of the pickup for the engine. Works great!!

Fair winds,
Dr. Michele

I have one of the RCI units in my system. I have never found water or debries in it It is in line before my filter. I believe the fuel pump volume or pressure is to high that it blows right tru this element I do have a pressure regular on the fuel pump and have adjusted it down quite a bit Do you have any opinion on this ?

[sailnautilus]

Each size of RCI fuel filter has a specified fuel flow rate at which it is effective; do you have the right size filter for your flow rate?? Have you visually inspected your tanks; is the fuel dirty?? Do you have Racors that are getting dirty??

Robert Fox at RCI is extremely helpful; you may want to contact him at bobfoxatrcieast@aol.com with questions.

Our fuel had contamination problems and I purchased one of these units after seeing the fuel cleaning services use them. If the fuel is clean and water-free, very little, if anything, is drained from the fuel purifier. The first few passes of dirty fuel required draining the unit frequently.
Hope this helps.... check your flow as that is critical.
Dr. Michele

[motion30]

Doc
thanks for the info. I have the small unit, I also saw the fuel polisher demo. I have the RCI unit on the suction side of the pump in front on the fuel filter If I open the drain with the pump running it had suction so it never drains . The kicker is you would want a high fuel flow to help scrub the tanks but the rfi unit apparent requires less flow My racors gather some water and debries at times But after running 1300hrs in the past three years the tanks are mostly clean unless I buy dirty fuel but of course the goal is to keep them this way

[lorenzo b]

Beebe recommends using a day tank, you filter the fuel with the standard Racor into a smaller tank for that days' use. That way you don't have to worry about dirty fuel or what may be at the bottom of your main tanks. Set it up so it's above the diesels and you won't have to worry about your fuel pump. If you do have crud in your tanks, you will know it before your diesel does.

[Cap]

Thanks to all for the input. As far as layout goes, what is the best way to accomplish this? I don't have room for a day tank, so that option is out. I was thinking of mounting everything on a piece of poly, a kind of control panel, then mounting that in the boat. One issue I have is placement. I really don't have any space to mount the system in a central location. Will mounting it in one hull affect the fuel flow for the other side? I guess what I'm asking is what affect, if any, will plumbing lines from the far side to the control panel and back have on the amount of fuel going to the engine? Does anyone have a schematic for a polishing system on a catamaran? I've looked at several that were for mono's, but I'm not sure they would be the same as far as distance? Maybe I'm making this harder than it is...

[colemj]

For polishing, you will want a high flow pump that matches the recommended filter flow. Racors need a good flow to do their best work, and you will want to have several tank quantities run through the filters for each polishing period. Small flow pumps like Walbro do not do the job well unless small filters are used with long run times. You will need a gear pump and large Racor-type filter. We use a Reverso pump, but there are other similar ones out there.

As for layout, you can break the system up and put the elements where ever it is convenient. Attached is a picture of part of our system showing the Racor 1000 and Reverso gear pump. Valves, if needed, can be put anywhere. Everything is connected by fuel hose.

A good system will ideally have separate intake and returns to the tank and the intake will go to all the way to the bottom. The return should go half way down to promote mixing and reduce foaming. Ideally, the intake and return would be at opposite locations on the tank. Also, you should use large diameter fuel hose to keep pressures down when using the gear pump.

Mark

[chris07732]

Originally Posted by sailnautilus

Each size of RCI fuel filter has a specified fuel flow rate at which it is effective; do you have the right size filter for your flow rate?? Have you visually inspected your tanks; is the fuel dirty?? Do you have Racors that are getting dirty??

Robert Fox at RCI is extremely helpful; you may want to contact him at bobfoxatrcieast@aol.com with questions.

Our fuel had contamination problems and I purchased one of these units after seeing the fuel cleaning services use them. If the fuel is clean and water-free, very little, if anything, is drained from the fuel purifier. The first few passes of dirty fuel required draining the unit frequently.
Hope this helps.... check your flow as that is critical.
Dr. Michele

sailnautilus: Looking at RCI unit for a polishing sytem, I note that there are no filtration specs units, just a claim for 99.9% water removal and 95-98%% solids/contaminents. All other makes claim 2,10,30 micron etc. Any idea what the RCI's effective micron rating is?

In your real world application, how does RCI handle sludge, algae that might happen with low use/storage of boat? With filter elements, you'd change out the element and be good to go. RCI, you have to blow it out??

The unit is attractive, just concerned about it's long term effectiveness in storage/low use applications

Chris

[zeehag]

best "system " i saw was home build , 2-3 racor sets and 2 electric fuel pumps. isnt rocket science. wasnt that expensive for the fella to make and worked great.