Shelf Life of Diesel Fuel

[boatpoker]

Scientific fact: Algae does not grow in your tanks. Certain types of bacteria grow at the interface of water at the bottom of your tank and the diesel but not algae.

Best way to keep your tanks clean and fuel in good condition is to actually use your boat. For summers here in Lake Ontario I keep only my day tank (80g) full and turn it over 7-8 times a season. When we run south we turn over all our fuel about every three weeks..... I once picked up a bad load of fuel that used a lot of filters but other than that I never had a fuel problem in 20,000 hours.

If adding a percentage of gasoline to your diesel make sure it does not contain ethanol as that stuff will absorb water and inhibit the blending of the gas and diesel causing a whole new set of problems.

[GordMay]

FUEL STORAGE INFORMATION:

BP on Diesel ➥ http://www.bp.com/liveassets/bp_inte...age_diesel.pdf

SAE on Diesel ➥ Long-Term Storage Stability of Diesel Fuels Effect of Aging on Injector Fouling-Stabilization By Additives Or Hydrotreating

Chevron on Diesel ➥ http://www.chevron.com/products/ourf...ech_Review.pdf

Chevron on Gasoline ➥ Technical Bulletin: Longer-Term Storage of Gasoline: Recommended Storage Practices

[idpnd]

Interesting topic, especially as I have just purchased a ton of fuel which must have been sitting there a couple of years.. Will probably put biocide in, then attempt to filter. I have also heard of people vacuuming the bottom of the tank to get rid of condensated water/dirt? Could there be rust issues down there if you have steel tanks?

[Highlander40]

Sorry here it is. Parker Fuel Polishing Module - Prevent Fuel System Corrosion

This is new technology. It uses piezo actuators to move a diaphram and pumps about 50 gal / day.

[Solitude]

Thanks for the links Gord

I read through the BP one and pulled this out...

Fungicides/Biocides

. These work by stopping fungus and bacteria from growing in the fuel and so prolong the life of the fuel. They are only effective on fungus and bacteria and will not stop other oxidation reactions from taking place. They are normally active at the water fuel interface where the fungus and bacteria grow. If fungus is present then a kill dose is required. Otherwise a maintenance dose is used to stop fungus growing. The disadvantages of biocides are:

• handling and mixing is hazardous because they are poisons.

• for a kill dose, killing the fungus can lead to a build up of dead matter which will block filters and also cause the fuel to oxidise.

• ideally, the fungus should be killed and then the tank emptied and drained out.

• maintenance doses are effective but no more so than regular water draining.

• disposal of water bottoms requires special handling with due regard to the environment.

[DRS]

As a truck driver in Canada I never added gas to diesel. We would on occasion add small amouts of Methyl Hydrate (1 gal MH to 200 Gal diesel)to thefuel tanks as it would disperse any water and prevent jelling.

[Highlander40]

The best way to deal with fuel is totally avoid all the disasters, tank cleaning and gunk buildup.
The FPM module that I posted does a real interesting thing. By moving fuel through the Racor at a slow speed (2 gal/hr) the filter is able to get the smallest droplets of water as they form. Not as water entering the tank but as water Leaving Solution with diesel. The key thing here, is that a change (drop) in temperature is required to form droplets of water. This happens every day as things cool down in the evening. The amount of water that fuel will carry in solution is so small that only by pumping super slow will the racors catch it, as it becomes a discrete water droplet.
By running the polisher every day or even round the clock, the tank will never have water in it.
This method also eliminates the need for a sump or pickup tube that sits on the bottom, because the fuel itself is the carrier that brings water to the Racor for collection.
No algae, no biocide needed. The constant movement may help with asphaltene buildup too but for long term storage an addative that will be burned as fuel (unlike biocides) is a good idea.

I know that I am sounding like a salesman here but I am just looking to have the best system for my boat. The FPM does something that no other system will. It keeps the fuel dry wether you run the engines or not!

Carl

[s/v Jedi]

Carl,

Explain to me why the FPM is better than a sump that is used to drain water and gunk regularly?

cheers,
Nick.

[Highlander40]

Nick,
Water tends to settle in the same places in the tank. Even with regular draining (weekly?) there will be some corrosion over time. With less than perfect maint, some scum may grow.
With the FPM I would think that the life of the tank would be determined by external problems like vibration, corrosion, wear, mostly due to poor installation. (no worries for you).
Think about this- the entire amount of water in your tank at any time would be equal to the smallest droplet that water can form. OR the total amount in the Racor bowl.

Carl

[s/v Jedi]

Carl,

Okay, I follow you now. We have aluminium tanks so there is no corrosion and all the water settles in the sump, where I can easily drain it plus any scum (I only get some very dark fuel in the sump plus a little water).

Water getting in the fuel tank is a continuous process. It gets absorbed from the moisture in the air and, if the tank isn't topped off, from condensation on the inside walls. The FPM will keep filtering while I let it collect and settle in the sump and drain it regularly.

What worries me is the FPM running that many hours in combination with the stiff price. I am not so sure it will be trouble-free. Also, you still have the same draining process that I have (from the filter bowl). I guess we'll have to wait for reliability reports from users that have it a year or so.

cheers,
Nick.

[Highlander40]

Nick,
Over the past 10 years I found that any water or any biocide that was added, ended up in the racor, a day later. My fuel tank has a sump and that combined with a flow rate of about one gallon per minute, vacuums up everything. I am curious about the FPM though.
The pump uses a piezo driven diaphram, they wont say more than that.
The current draw is almost nothing and even if it did fail there are no shaft seals to leak.

The dark stuff you drain from the sump? does it smell just like biocide?

Carl

[s/v Jedi]

I use Startron (the blue stuff) and that mixes up with the diesel completely. It also turns the diesel into a much lighter color after a couple of days.

The dark stuff are the heavier components in diesel that isn't top quality (it separates). This is like it is everywhere in the Caribbean. I mix it back in with polishing but some doesn't pass the 10 micron filter I use for polishing. I draw fuel from the sump while polishing.

FPM: I don't worry about it's power draw nor leaks... I worry about having to replace it every year or so which would make it too expensive.

ciao!
Nick.