Pretty basic question but I don't have experience with diesel fuels. When diesel gets water in it does it combine, like alcohol absorbs water, or will it separate like gasoline and water? A friend had a question regarding an outdoor storage tank having condensation spoil the fuel and I was figuring water would separate to the bottom with diesel staying on top. Right or wrong?

Second question: can you add some alcohol to diesel to force it to combine with the water so you don't get fuel starvation?

Thanks....

 

Diesel will separate from water if you let it rest and it's not doted with any emulsifier.
Combining diesel with water and alcohol to make the water disperse in diesel is a very bad idea. Water is a corrosive to a lot of the parts in the fuel system. Since it doesn't lubricate too well the wear is also quite bad. There are some additives that will make the water fall out quicker, for the storage tank you just need to lower a thin piece of hose to the bottom of the tank and then suck the water out with a pump. (Standard procedure for fueling stations, only the hose is replaced with a fixed pipe.)
A good external supply has a floating pickup that will skim the clean stuff from the surface and will not agitate the fuel to avoid all the crud being brought to flotation.

HTH

AlpineRAM

 

Aha! Thanks for the excellent info, AlpineRAM! Sounds like a very practical way to eal with the problem. I was thinking if it separates then he could tip the tank mount a little so the dispensing valve is above the waterline but simply removing the water from time to time is the right way. Also the floating pickup would guarantee clean fuel each fill. Thanks!

 

if i ever feel that i may have gotten water in my fuel, i had 3 drops of demulsifier to it just too be safe.

 

Most above ground tanks have a tap on the bottom for a valve just for the purpose of draining water. The proper way to install the tank is with it tilted slightly towards the valve.
Big problem with water in your fuel tanks is that the water/diesel interface is the environment that diesel algae loves to grow. The algae resembles snot and does an excellent job plugging up filters.

 

So, it sounds like a fuel treatment of some type is good insurance in addition to the drains and skimming. What would be a good product for a storage tank?

 

If you do regular maintenance on the tank drain, to eliminate H2O... it's all you need. Without the water...algae can't grow and rust. etc will not form.

There are some good additives out there to increase cetane and upper cylinder lubricity, and also to keep fuel system clean. Use them if you like.

RJ

 

Down south they use anti-Algae additives to prevent stored diesel from growing in the tanks in the first place. Boat owners are particularly susceptible to this pattern. The boat sits all week in the blazing sun on the trailer or in the slip and without benefit of a fuel polishing system, the algae blooms in the tanks. Draining the fuel/water sep before every fill-up will help prevent damage to your engine.

 

One thing that was missed with the above ground tank is the rust that occurs
in the roof of the tank from the condesation. We have to run a marine type filters in our deisel equipment that is fueled from metal tanks. The Racor SM2000 or similiar is excellent for separating water and other materials from the fuel system. We don't run a filter in the racor, just use it to spin out the water and junk. The catch bowl on the racor can be easily drained, removing the junk.

I use to run a Racor on my 6.2 and 7.3. I've considered it on the Cummins, but never installed it yet. I would see water in the racor in the winter up north caused by the hot fuel return making the tank sweat.

Dave

 

Hey, thanks for the great info, guys, that helps a lot. I'm going to e-mail a link to this thread to my friend and let him read it for himself. I hope he joins up here as it's a great forum, one of the best for sure!

 

would there be a problem having a solid filter w/o a water saparator on the truck if ur driving it daily? where do the big trucks have the separators then? i can't see them...they're certainly not on the fuel filters

 

You could mount a separtor type small filter on the frame rail under the drivers door with no problems. It should work real good given the advantage of having a mechanical fuel pump in front of it.

Check with a marine dealer for a small racor filter like this one, RACOR
120R-RAC-02. This has a metal bowl on it. You can get them with a high impact clear bowl to see whats in there. This model has a spin on filter with the water serpartor attached to the filter.

Here is a link. Look at the Diesel Spin on Filters http://www.maesco.com/products/racor/racor.html

The best one is the turbine type filter. The SM2000 is a turbine type filter/separator. Don't know if that type is still available.

Dave