Fuel Polishing System Installation

[Rustic Charm]

Originally Posted by Mr Filter

If you use a fuel polisher you need to use a fuel conditioner as well.
If you don't you will break the fuel down quicker.

Why? All fuel 'polishing' is doing is running the fuel through a filter. Why does this 'break the Fuel down'?

[Aloha_float]

A conditioner is not going to help


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[Mr Filter]

A proper additive will help to stabilize the fuel. Because the fuel is be moved the stabilizers would be used up. Been doing this for 25 years. I have boats that have never had a fuel problem in 25 years.
With a proper additive you need to have a demulsifier in it to remove the water.
This is a very complex issue. But can be solved very simply.

[Rustic Charm]

Originally Posted by Mr Filter

A proper additive will help to stabilize the fuel. Because the fuel is be moved the stabilizers would be used up. Been doing this for 25 years. I have boats that have never had a fuel problem in 25 years.
With a proper additive you need to have a demulsifier in it to remove the water.
This is a very complex issue. But can be solved very simply.

Why do you say running fuel through a filter will 'break it down'?

[Mr Filter]

When you move fuel the stabilizer that is put in will be used up. Fuel today
has a shelf life of about 30 days before it starts to separate. The biggest cause of the separation is time and heat. That is why stabilizer should be added to prevent this from happening.

The best thing to do for fuel is to transfer what you are going to use. On large ships the day tank is what you consume that day. They clean the fuel prior to the day tank and then it is consumed.

When most fuel polishing systems are installed they are not put in correctly. The polisher should have its on separate tube in the tank so it cleans the fuel at a lower point then the engine pick up tube. If you don't then you should just use the filters for the engine.

By using a separate tube you can strip the tank of contamination instead of polishing the fuel. By stripping the fuel at a lower point then the engine pick up tube you have more room for cleaner fuel.

We can go into great depth when ever you want. I would first treat the fuel first with the proper additive before you spend a fortune on a polisher.

[ErikFinn]

Originally Posted by Mr Filter

When you move fuel the stabilizer that is put in will be used up. Fuel today
has a shelf life of about 30 days before it starts to separate. The biggest cause of the separation is time and heat. That is why stabilizer should be added to prevent this from happening.

The best thing to do for fuel is to transfer what you are going to use. On large ships the day tank is what you consume that day. They clean the fuel prior to the day tank and then it is consumed.

When most fuel polishing systems are installed they are not put in correctly. The polisher should have its on separate tube in the tank so it cleans the fuel at a lower point then the engine pick up tube. If you don't then you should just use the filters for the engine.

By using a separate tube you can strip the tank of contamination instead of polishing the fuel. By stripping the fuel at a lower point then the engine pick up tube you have more room for cleaner fuel.

We can go into great depth when ever you want. I would first treat the fuel first with the proper additive before you spend a fortune on a polisher.

I believe you are referring to Petrol/US "gas" ?
The fuel polishing system here is for diesel fuel.

[Mr Filter]

No that is for diesel. Diesel for many years has been made with different types of crude oil. And it is now being cracked. This is where the problem starts. Also now the fuel companies are using a cutting crude oil and we are seeing bigger problems now. We are now seeing a 2 to 5 micron metal catalyst that is in the fuel and is scoring pumps and injectors in the newer engines.
I deal with engine OEMS every day and the problems with fuel are becoming very bad. On older engines you do not see these problems.

[Aloha_float]

I find it frustrating to read the "expert advice" on the fuel topic when this is something that we research daily.

Diesel Fuel has three key issues -

1. oxidative stability - yes fuel corrodes - and there are many factors that play a role in this. Shorter chain chemistry and hydro treating has resulted in the formation of hydroperoxides which is acidic and contributes to oxidation - physical stability (the precipitation of asphaltenes) is no longer the major issue however, some insoluble do precipitate out of the fuel over time - but not significant enough to impact quality unless a significant amount of time passes and other contributing factors

2. water - diesel fuel contains water naturally and has a natural absorption rate however, excess water will allow the formation of microbial colonies that contribute to modifying the overall acid number of the fuel which contributes to oxidation stability issues

3. corrosion - now this can be handled in a couple of ways - either through the use of metal deactivators in fuel additives or at the refinery and with the use of microscopic coatings known as filming amines. Both can be effective however, filming amines can replace adhesions of biofilm from tank walls eliminating microbial contamination. Corrosion by-products (metal salts) play a role in catalyzing some of the reactions in fuel that result in oxidation.

So we see a circular relationship with these three key factors - todays conventional additives typically deploy old-school detergents which have been proven ineffective with modern fuels and modern engine technologies (see some SAE studies on this topic).

The use of metal deactivators is still quite common and can be a very effective short term solution to the catalyzing of oxidation however, if the source of metal salts (corrosion) is not dealt with, then the solution is simply temporary.

Lubricity improvers have been deployed as well as the "new" ULSD has lost significant lubricity due to the stripping of aromatics from the fuel during the distilling process.

Some are now also experimenting with water emulsifiers and de-mulsifiers and this is still being debated. Whatever you do, do not use alcohols as this allows water to disperse in globules and you will quickly find yourself looking for a mechanic to change your injectors that are either seized or destroyed.

in short - most additives are temporary solutions and biocides are not very effective at ridding of a badly contaminated tank and not all biocides are the same as the strain of bacteria in your fuel may vary due to heat, chemistry and water content and there are specific biocides to kill specific bacteria. That is why we get different scripts every time we go to the doc for different bacterial infections.

but what do I know? not much except that most still refer to it as algae which is also misleading (unless you have a glass tank exposed to the sun)

fuel polishing is simply filtering out sloughing deposits and not fixing the problem. Yes you get clear fuel in your racor but you maintain a beautiful biofilm inside you fuel system that is setting up beautiful little corrosion sites that accelerate corrosion issues and tank failures that remain unexplained - or are they? Could this be MIC? microbially influenced corrosion?

My background? materials engineering
My experience? offshore marine industry?

I will be presenting a paper to the offshore marine sector next week in Singapore if you find yourself moored in the area...or sailing in Phuket the following week in the monsoon...

Best of luck to those still trying to find the right solution to this problem.

[Dockhead]

Originally Posted by thinwater

That was 3b. Via breathing. Actually, it's worst in the spring, when the tank is cold but the air is warm and moisture laden. My comment was to point out that with a silica gel vent filter, condensation is eliminated and degradation due to air exposure is reduced at least 50% based upon lab and field testing. We've tested this with gasoline and diesel.

. . . .

While there are some that will deny condensation, since empty tanks don't fill, we were able to re-create the effect repeatably. Additionally, underside roof corrosion is such a point of concern in large tank farms that inspectors are required to inspect the the roof structure before tank entry; I've found corroded beams that fell and were on the floor! Condensation, of course, was the cause. Clearly, having fuel in the tank changes the dynamic though the effects of organic vapors, absorption, and precipitation. Complicated, but demonstrable.

Condensation of water in fuel tanks comes from the fuel, not from the air (initially). An empty tank will suffer less condensation than a full one. So you guys concerned about it should keep your tanks closer to empty -- the less fuel in them, the less condensation.

I keep mine nearly empty in the winter time, and never found a drop of water in it (I open it up and clean it out every two years).

The reason is explained pretty well here:

As a physical chemist and mechanical engineer, who has for nearly 40 years worked deeply in fluid and thermal sciences, the ultrapurification of fluids (including exotic 'oils', dielectric oils, etc. etc. for the electric power generation, semiconductor, ultrapure chemical, bio-pharma industries, etc. ), etc. etc. etc. .... Mr. Pascoe is essentially correct, not totally correct but close. Sorry to state this; but, most of you who somehow 'intuitively' oppose Mr. Pascoes statement are not correct.

1. Most oil made from cracking or distillation are almost completely dehydrated by the heat of the process - water content essentially nil.
2. When in CONTACT WITH **ATMOSPHERIC** AIR, water (as vapor and as free gaseous molecules) enters the mass of oils, etc. due to ***vapor pressure equilibrium drive (partial pressure of the water vs. the partial pressure of the oil)***.
3. Water in oil exists in various 'states':
a. molecular water (azeotropic mixture) ... insensible without using 'instrumentation', etc.
b. emulsified water (water that is held 'in suspension') ...insensible without using instrumentation, etc.
c. free water ... sensible water that can be observed *without* instrumentation, etc. In typical oil mixtures, free water is the only 'phase' of water able to 'gravimetrically settle out'.

Water that is 'condensing' on tank walls, etc. is the result of the ~'end stage' of the equilibrium changes to the oil being SATURATED with water ---- the oil is now becoming **fully SATURATED** with water (molecular water, emulsified water, AND free water). The same physical laws of vapor pressure 'equilibrium' which is temperature dependent can reverse the equilibrium direction so that the relatively warm oil, etc. begins to lose it water content ... and the water (as vapor) begins to condense on adjacent cooler surfaces. The greater the water saturation of the oil the greater the equilibrium drive now in the 'opposite direction' if the adjacent surfaces, etc. are cooler (and according to the partial pressure of the water, etc.) ... and the water vapor in the oil NOW condenses on the cooler tank walls ... only to gravimetrically fall/slide back down into fluid until it settles on the bottom.
If you took the same amount of oil and poured into an open 'pan' and exposed it to atmosphere .... it would 'pick-up' essentially the SAME amount of water as if it were in a 'tank' exposed to atmosphere ... and there would be NO evidence of 'condensation' !!!!

The water that gravimetrically settles to the bottom no longer becomes a 'true' part of the mixture (a 'liquid-liquid phase boundary' forms between the oil and free water) .. and this influences to the sum of the partial pressures 'above' the phase boundary ... but leaving the oil (+water mixture) above the boundary free to re-equilibrate and accept vapor migration from additional (humid) atmospheric air in contact with the oil surface. .... and now what is occurring (again by equilibrium) could be described as a 'pump with out moving parts' being operated solely by physical & chemical 'equilibrium'.

Water that is 'condensing' on the walls of a tank is primarily a SYMPTOM that the oil is SATURATED with water - chemical equilibrium (partial pressure equilibrium) moved the water vapor in the atmosphere into the oil.

Dont want 'water' in your oil, .... keep the MINIMUM amount of oil in your tank, put a desiccant trap (silica gel, activated alumina, etc.) on the vent line .... or if you have a 'vacuum rated' tank simply close the vent valve when the engine is off; the minimum mass/volume of oil will 'pick-up' the minimum amount of water vapor ... so DONT keep your tank 'topped-off' especially if you're not using the oil quickly !!!!! Its the MASS of oil in the tank and the sum of partial pressures (equilibrium) of oil AND water vapor that is causing the 'transfer' .... not a tank wall !!!!! Condensation is a SYMPTOM that oil is ALREADY becoming fully saturated with water.

In 'industry', ultrapure oils that have become saturated with water are typically placed into a vacuum chamber, a strong vacuum is applied (to change the partial pressures which reverses the equilibrium) ... and THEN, the oil is run through water absorbing 'filters' (filters that contain the starch hydroxymethylcellulose (the same stuff in "pampers") to achieve less than 1 ppm water content. If water saturation is your problem you can buy filters that contain a water absorbing starch (for gasoline fuels) from the 'typical' suppliers.

Question? If your 'intuitive' condensation hypothesis are correct, then why don't EMPTY tanks (exposed to atmospheric air) automatically fill up with water ????? :-)

BTW- My 'fuel system' includes a constant recirculation filtration stage (including a free water 'knock-out' trap), the tank VENT line includes a bio-blocking filter to retard **fungal spores**, and the vent includes a desiccant chamber to remove incoming water vapor down to -40 deg. dewpoint ....
I gots no water, gots no biological fouling, gets my 'filters' free but hardly ever change them, .... gots NO 'fuel problems' in a 100 gallon black iron fuel tank ... and I never have to down into the bilge during a heavy seastate to change out filters .... and 'power-puke' at the same time. My system also has a 2 gallon 'day tank' that stores filtered oil ... if there is ever a 'problem' I can simply open the 'weir valve' and vent valve on the day tank and let the oil 'drain by gravity' down to the engine .... for about ~2-3 hours run time - time enough to 'motor-away' from any danger, etc.

Water enters oil/fuel by *chemical equilibrium* (the sum of partial vapor pressures of the 'constituents'); the MORE oil, the MORE water. Condensation is a *symptom* that liquid is now FULLY SATURATED with water. Empty tanks (with atmospheric vents) dont automatically fill with water.

:-)"

Myth of Condensation in Fuel Tanks - Page 4 - SailNet Community


One of my sailing buddies here is an engineer with BP who designs maintenance programs for their enormous tank farms. He says exactly the same thing. Keeps his tank as empty as possible in the winter time.

My father, on the other hand, subscribes to the "keep your tanks full" myth, which means we waste an hour topping them off after every little cruise on his boat. We pump water out of his tank every year , and every couple of years he has an outbreak of diesel bug, despite religious use of biocides

[Rustic Charm]

I AM SO CONFUSED...

[Strait Shooter]

If you WEREN'T confused, I'd be concerned!

[Maine Sail]

Originally Posted by Dockhead

I keep mine nearly empty in the winter time, and never found a drop of water in it (I open it up and clean it out every two years).

Bingo! My tanks have been empty every winter for over 25 years. Never a single droplet... Last winter was the first winter I left it mostly full but not chock full. The only reason I did this was because I installed a diesel vent line drier and I wanted to see if the beads would go from blue to pink. It is now mid September and the beads have not changed color....

I also have this little beauty set up on the second floor of my barn under long term testing. I did this after a number of net experts strongly stated as a fact that an empty tank will condensate and miraculously accumulate with water..... I have never once even found moisture on the tank walls.

Tank is empty, all tappings were plugged except 5/8" vent which leads directly outside the building. This is a real sailboat fuel tank out of a Sabre... (note where my own sailboat is stored over the winter, the two tank vents are but 4' from each other and at nearly the same height off the ground.) My barn see wider temp swings though....



These are a few of my updates to the empty tank condensation testing:


EDIT 6/25/14: Just checked it again last night and it is still bone dry. Not even a hint of moisture. I chose to check it yesterday because humidity levels have been in the 90%+ range and night time temps have been dipping to the high 40's 47F - 49F and day time barn temps (second floor uninsulated roof) reaching 118F!!! That is approximately a 70F swing with 80-90% humidity.... Still dry......

EDIT 5/18/14: About two months ago I set it on some 2" thick stone pavers as some surmised the tank needs to remain cool as it would if in the belly of a boat at ocean temp. What the heck it took me five minutes to add this to the test. Up here in Maine, when hauled out for the winter on the hard, there is no "ocean temp" but I still placed it on the slower to change temperature stone pavers anyway.. I was fully expecting some drinking water in this tank but foolish me, STILL BONE DRY.....

[ontherocks83]

Maybe i am misundetstanding but am I reading it that if you add stabil and then filter the fuel does the filtering strip the stabil out of the fuel?

[Mr Filter]

No the extra stabilizer will help keep the fuel from separating into a sludge. What you see is the sludge which is crude oil going back into its original form.
When I get a chance I will send you a paper that I have been adding to since 1992 explaining the fuels over the years.

I am visiting boatbuilders in NC and will try to do it tonight

[Aloha_float]

Originally Posted by Maine Sail

Bingo! My tanks have been empty every winter for over 25 years. Never a single droplet... Last winter was the first winter I left it mostly full but not chock full. The only reason I did this was because I installed a diesel vent line drier and I wanted to see if the beads would go from blue to pink. It is now mid September and the beads have not changed color....

I also have this little beauty set up on the second floor of my barn under long term testing. I did this after a number of net experts strongly stated as a fact that an empty tank will condensate and miraculously accumulate with water..... I have never once even found moisture on the tank walls.

Tank is empty, all tappings were plugged except 5/8" vent which leads directly outside the building. This is a real sailboat fuel tank out of a Sabre... (note where my own sailboat is stored over the winter, the two tank vents are but 4' from each other and at nearly the same height off the ground.) My barn see wider temp swings though....



These are a few of my updates to the empty tank condensation testing:


EDIT 6/25/14: Just checked it again last night and it is still bone dry. Not even a hint of moisture. I chose to check it yesterday because humidity levels have been in the 90%+ range and night time temps have been dipping to the high 40's 47F - 49F and day time barn temps (second floor uninsulated roof) reaching 118F!!! That is approximately a 70F swing with 80-90% humidity.... Still dry......

EDIT 5/18/14: About two months ago I set it on some 2" thick stone pavers as some surmised the tank needs to remain cool as it would if in the belly of a boat at ocean temp. What the heck it took me five minutes to add this to the test. Up here in Maine, when hauled out for the winter on the hard, there is no "ocean temp" but I still placed it on the slower to change temperature stone pavers anyway.. I was fully expecting some drinking water in this tank but foolish me, STILL BONE DRY.....

Put the tank outside for that test. Inside the barn isn't a real fair test.

Corrosion in vapor space is from acetic acid.

All else is misleading...full tanks help prevent vapor space corrosion

There are additives designed specifically to handle vapor space corrosion

Read the battelle report


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