Fuel Polishing System

[osirissail]

Simplicity is the key to getting around to using the system. Rather than setting up an external system of filters and pumps, I put a 3-way valve in the normal engine fuel supply system that enabled me to re-route the flow out of the fuel filter to the electric diesel fuel pump and then back to the fuel tank via the return line/hose.
- - All I have to do is turn on the electric diesel pump and move the valve and fuel is pumped from the diesel tank through the main filter(s) and then back to the tank. As a side benefit after changing fuel filters, I run the electric pump to suck the air out of the fuel filter.
- - As an extra added feature I added another valve after the electric diesel fuel pump to route the output back to the normal engine fuel supply lines. This allows me to pressurize the engine fuel system using the electric pump and then "bleed" the engine high pressure pump and fuel system a lot easier than the "old way."

[Pete7]

Now that is a clever idea

[Target9000]

We're in the middle of a repower and part of it is to change the fuel system and tanks. I didn't like the idea of having a fully separate fuel polishing system. Bud Taplin over at WorldCruiser sent/suggested the attached photo to create a very simple solution. Its close what osirissail suggested above but I thought a visual might help some folks.

[colemj]

Fuel polishing takes many runs through a filter to be effective. And the fuel flow must be matched to the filter rating. You also want to optimize the particle size limit of the filter as well as the filter capacity for polishing purposes vs. engine running purposes.

Systems utilizing a small, low flow electric pump and existing engine filters will not polish fuel unless they are run continuously, the filters used are not optimal for engine usage and one is willing to change them often. Also, one takes the risk that the filter will clog unexpectedly when needed for the engine. These systems simply will not agitate the fuel in the tank or be sufficient for taking care of any fuel problems. They may help slightly for fuel maintenance if you leave large amounts of fuel setting unused for long periods of time.

Please just take this as advice and not argument. I don't care what you install and am happy if you are.

Mark

[rdempsey]

This is my approach as well. Works Great!

Originally Posted by osirissail

Simplicity is the key to getting around to using the system. Rather than setting up an external system of filters and pumps, I put a 3-way valve in the normal engine fuel supply system that enabled me to re-route the flow out of the fuel filter to the electric diesel fuel pump and then back to the fuel tank via the return line/hose.
- - All I have to do is turn on the electric diesel pump and move the valve and fuel is pumped from the diesel tank through the main filter(s) and then back to the tank. As a side benefit after changing fuel filters, I run the electric pump to suck the air out of the fuel filter.
- - As an extra added feature I added another valve after the electric diesel fuel pump to route the output back to the normal engine fuel supply lines. This allows me to pressurize the engine fuel system using the electric pump and then "bleed" the engine high pressure pump and fuel system a lot easier than the "old way."

[motion30]

Originally Posted by colemj

Fuel polishing takes many runs through a filter to be effective. And the fuel flow must be matched to the filter rating. You also want to optimize the particle size limit of the filter as well as the filter capacity for polishing purposes vs. engine running purposes.

Systems utilizing a small, low flow electric pump and existing engine filters will not polish fuel unless they are run continuously, the filters used are not optimal for engine usage and one is willing to change them often. Also, one takes the risk that the filter will clog unexpectedly when needed for the engine. These systems simply will not agitate the fuel in the tank or be sufficient for taking care of any fuel problems. They may help slightly for fuel maintenance if you leave large amounts of fuel setting unused for long periods of time.

Please just take this as advice and not argument. I don't care what you install and am happy if you are.

Mark

The professional fuel polishing guy in my area uses a pump that can pump 16gal per min. I think that is the same as the gas station pumps. I do believe the biggest problem is getting the tank stirred up enough to carture all the junk. It seem a rough water ride will stirr things just fine. Nothing like being in a 8' following seas and have the filter stop the motor

[Target9000]

Originally Posted by motion30

The professional fuel polishing guy in my area uses a pump that can pump 16gal per min. I think that is the same as the gas station pumps. I do believe the biggest problem is getting the tank stirred up enough to carture all the junk. It seem a rough water ride will stirr things just fine. Nothing like being in a 8' following seas and have the filter stop the motor

Maybe this is the time you should be sailing (only) while running the polishing system. Think of it as a free "boost" for the polisher.

[osirissail]

Yes, the biggest problem is getting to the fuel that is "below" the pickup tube in the fuel supply system plumbing. Normally, the fuel supply tube is arranged so that it is a few inches above the bottom of the tank.
- - How anybody is going to get to the sludge and water that accumulates below is a good question. I have never seen any fuel tanks with a large size access valve to the tank where one might insert a hose or tube to probe the bottommost corners of the tank.
- - In my description of my system I did not specify the size of the electric diesel pump so you could choose a high flow or lower flow pump as you desire. I use the Walbro pump as it is the only one at the time that was UL approved for permanent installation. Other pumps might not be so approved which might jeopardize your insurance coverage.
- - Also my system has the Racor Vacuum guage installed on top of the filter so I can see how much clogging there is in the filter cartridge.
- - The system diagram from World Cruiser Yacht Co (post #19) has the electric fuel pump BEFORE the filter. I feel this is rather dangerous for two reasons. First, some filter assemblies are only designed for suction pressures and might leak if positive pressure is applied to them. And secondarily, putting a positive pressure on the filter element may cause a rupture or allow dirt to be forced through the filter membranes and subsequently into the engine system.

[motion30]

I am lucky in that my tanks have a 3/4'' npt fitting at the bottom of each tank Putting the pump before the filter subjects the pump to all the junk in the tank Probably not good for the health of the pump

[ATC]

We clean fuel tanks daily and we have old salts that want their fuel polished. We also have customers that request their tanks be clean. For these two applications we take two different approaches. We use two different pump/filtration systems because the processes are different.

We gain entry to the tank usually via the fuel sending unit where we focus on the bottom of the tank. For polishing we will remove all of the fuel from the tank while filtering at 10 microns, placing the fuel in clean containers. Then we change filters from 10 micron to 2 microns and return the fuel to the tanks.

For tank cleaning, we use a different pump, one that has the ability to create agitations in the tank. We gain entry to the tank usually via the fuel sending unit where we focus on the bottom of the tank. At the bottom of the tanks is the home where all of the demons rest. We will agitate these demons and pull them from their lair, capturing them in our filtrations system while sending clean fuel back into the tank at a very high velocity. The end results you have a clean tank and clean fuel. The fuel is not filtered down to 2 micron during these process because the agitation is required.

We can tell if bio-cides have been used in a fuel tank, the bottom of the tanks are covered with a thick matt of small granular size bugs. We do not endorse the use of bio-cides for the very reason they do not treat the source of the problem, which is water. Water is the only food source for the micro-bio growth (also refered to as algae). Therefore do alway with the food and there is no need for a bio-cide.

When we come across farm/construction equipment, a truck, a boat, anything with saddle type tanks, we find one tank to have a higher degree of contamination, largely due to the orientation while being stored for long periods. The side facing one direction will see a greater temperature change causing condensation to develop, again the food source for the demons.

When a customer demands his fuel be polished I reply "this is like putting the baby back in the dirty diaper".

Any filtration is good, but don't be sucked into thinking all is OK.

[osirissail]

I am just curious how access is obtained in sailboats which do not have "fuel sending units." I assume that label is talking about a fuel quantity gauge sending probe.
- - There are a lot of sailboats that do not have such things and getting access normally involves removing either the fuel fill hose or something else. In any case, the removal and re-installation of the hose, etc. needs to be expertly done to prevent diesel fuel leakage into the interior of the vessel.

[DeepFrz]

Mark (colemj) has my vote for the way to do things except I would run the return line all the way down (within an inch of the bottom). If you are installing a fuel polishing system do a proper job and install one that is separate from the engine fuel system and with enough capacity to stir things up in the tank.

Also, its a good idea to make sure the tank is clean and to keep it clean or at least inspect it on a regular basis. As the man said, why bathe the baby and put it back in a dirty diaper.

[ATC]

Originally Posted by osirissail

I am just curious how access is obtained in sailboats which do not have "fuel sending units." I assume that label is talking about a fuel quantity gauge sending probe.
- - There are a lot of sailboats that do not have such things and getting access normally involves removing either the fuel fill hose or something else. In any case, the removal and re-installation of the hose, etc. needs to be expertly done to prevent diesel fuel leakage into the interior of the vessel.

Your reference to the "fuel quantity gauge sending probe" would be the same as a FSU, however when you have to but a new gasket you may have to explain to the clerk just waht you are doing.

We do come across both sail and power that no not and have never had any means to determine the quanity of fuel on board. When this occures we simply drill a 1.5" diameter hole in the tank, drill and tap five screws, then install a FSU gasket & plate that the owner can in the future either drill ant tap the plate then use a dip stick or replace the plate with a FSU from the likes of West Marine. Access to some tanks can be very difficult, there are times we may opt to cut a hole, install a Beckson type hatch for future maintenance.

As for the removal of fuel lines, this is something we try to avoid. I have an agreement with all of the mechanics, "we don't turn wrenches, they don't clean tanks". Our network of qualified mechanics not only include the marine segment, but all so heavy equipment, farm equipment, emergency generators and fleets. We keep our fuel work very simply, get in, clean, determine the issues and make recommendation to the clients.

We carry millions of dollars in insurance just to be able to come on site at most marinas, military installations, country clubs, etc. However we will be dragging 1" ID black rubber hoses in to the interior space of luxury yachts with wall to wall white carpet. We are currently doing more jobs in gasoline contamination but a higher volume in gallons in diesel.

[Cap]

Ok, again thanks for all the input, lots of great information. I bought a Racor 500FG turbine filter. It says it will do 60gph, and that's all the fuel I carry, two 30 gal tanks. I don't know what pressure my existing fuel system can handle, two 13hp diesels, so what is the best choice for a pump to make this system work?

[osirissail]

Using Racor 500's on such small engine systems is really overkill and a lot of wasted money. Racor 100 series would work better.
- - The Racor 500's Turbine filters need a significant fuel flow through them to activate the "turbine" effect for water separation. Too low a fuel flow defeats the turbine and you end up having a filter that does nothing more than process the fuel through the pleated cartridge. Bigger is not always better.