Reason for Water in Diesel?

[RWHP]

I am hopping someone on this board can give me a good explination of why/how Diesel absorbs water. A friend of mine made a bet with me that Diesel cant absorb moisture, and will actualy completly separate if placed in the same area.

I know this is partly true but, I also know that water is a big reason for fine diesel filtration.

Any input on this subject would be great.

[BD]

Your friend is right in that diesel and water will separate if left undisturbed. Now I am not saying that there is absolutely zero percent water in diesel as it leaves a refinery - but it is way less than 1 percent - I will check on the specifications tomorrow.
The water that is found in diesel fueling systems typically comes from condensation of water vapor in the air as the storage tank heats and cools during the day. If diesel and water are agitated it forms an emulsion that takes time to separate.
Here is some information on it - along with lots of other information from Hastings Filters - http://www.hastingsfilter.com/engineering/tsb_95-1.html

Bill

[a bear]

Low vapor pressure causes diesel storage to breath as temps change. Fuels with high vapor pressure such as gasoline is allways venting which prevents condensation from entering tank. A good example in when you get that puff of pressure when you open a gas can. Positive press no condensation can enter. Once water enters most will settle at bottom and cause other problems if left there. But thats another story. smile.gif

[george morrison]

Diesel fuel is hygrosopic: that is, diesel fuel will literally draw water into itself and hold it either in a loose suspension or as an emuslification, depending on the chemical advantages, contaminants, etc.
As opposed to gasoline which will not hold water in suspension. Period...
And yes, if diesel fuel is allowed to sit motionless, mother nature will begin working on the heavy water droplets and it will settle out as free water. Not completely though. Some water will continue to stay in emulsion.
It is impossible to keep water out of diesel fuel. It is always there to some degree. Which is why JK and I are firm proponents of chemically "locking up" water molecules so they do not have a tendency to fall out as free water. Free water is a fuel system destroyer. Water that is locked up, surrounded by a lubricating chemical bond poses no problems for our Duramax engines.
George Morrison, STLE CLS

[MaxDiesel]

George,
Exactly what do you use to "chemically "locking up" water molecules" that you mention. Is there a particular brand and product? Is this an achohol base product?

Thanks

Jim

[RWHP]

Thanks a lot guys, printing your posts now.

[SPICER]

MaxDiesel,

I would never attempt to speak for George, but I feel pretty safe with this one.

George uses and sells Primrose 405 and 409(winter). They are both emulsifiers(bind water and let it pass ambiguously through the engine). They are also additives which will give your fuel the qualities of a Premium Diesel Fuel. Check out avlube.com.

These DO NOT CONTAIN ALCOHOL! Do NOT use any product containing alcohol.

John Kennedy uses and sells FPPF, a similar product that emulsifies. His site is Kennedydiesel.com. Both are great, I use Primrose...SPICER

[ 03-18-2003: Message edited by: SPICER ]</p>

[BD]

Excellent discussion on this topic - was talking to Mr. Morrison this morning about this as I was buying one of his oil pan magnets.

I was trying to remember why diesel tanks "breathed more than gasoline tanks - totally forgot about the vapor pressure issue.

Regarding the locking up of water - water has a high surface tension which allows it to collect into large drops. If you ever played with liquid mercury on glass you saw this phenomen to an even greater level. I believe what actually happens is that the chemical additive reduces the surface tension of the small water particles so that they cannot form large drops and consequently stay relatively uniformly distributed in the diesel as very small particles - if you will - very finely emulsified. My guess is that it would also contain some sort of biocide to stall or reduce bio activity/formation.

After typing all of this I went onto google and did a search on Primrose 405 which - see the attached link -http://www.primrose.com/wtds/405%20Power-Master%20WTDS.pdf COuld of saved myself a lot of typing:)

Bill

[MaxDiesel]

Cool...and thanks spicer

[Racor]

A little bit of info:

Back in the 80's We ran an experiment to prove that a even a fine emulsion would settle out in take of fuel. We filled a 12 inch diameter x 3 feet tall open plexiglass tube (with a bottom on it) with #2 diesel that had .25% water emulsified into it by a 7500 rpm centrifugal pump. The droplets ran 200 microns and less. A few large drops of water formed on the bottom over the next week, and the fuel remained cloudy. Over the next few weeks after that, the water just evaporated into the open air and the fuel cleared up. We were wrong. The result might have been different if it hadn't been inside at 75 degrees, but probably not. That test is why we have two SAE tests; a droplet removal test and an emulsion removal test. If the emulsion had settled, SAE might have opted for one droplet removal test.

[SPICER]

Racor,
I don't know if I follow your point. I have read other threads on this topic but don't remeber your stance on the emulsifier vs. de-emulsifier issue. I am assuming you would prefer a water separator since your filters are designed for this purpose. Fill us in... SPICER

[Racor]

Emulsions do exist in the fuel delivery system between the refinery and your truck.

Emulsions persist, and in any form, they can cause corrosion in the injection system.

I support removal of the emulsion by the DMAX filter(with proper maintenance.)

I can't support any additives not approved by GM. However, if you must use an additive, de-emulsifiers that do not contain any type of alcohol are preferred over emulsifiers or anything containing any type of alcohol.

[george morrison]

Racor, regarding your statement " support removal of the emulsion by the DMAX filter(with proper maintenance.)" I would agree completely, if only the water removal really worked! I have 23 before and after fuel analysis performed on Duramax engines and in every single case the KF measured water "in" was the same as the "out".. This is not only true for the Duramax; the same is true for the Ford PSD, the VW TDI, etc. etc. I have not reviewed one single case of OEM filter/water removal system has had any impact whatsoever on entrained water. i.e. 66 ppm water into the filter, 66 ppm water out of the filter, Karl Fischer methodology.
This is the basis of my concern. Fuel that has this level of loosely emulsified water could well settle out anywhere in the system if allowed to be stationary, experience temperature changes, etc. By chemically locking up the entrained water, we ensure that the 66 ppm will indeed remain in the fuel, enclosed by a lubricating boundary, which then eliminates the corrrosion possibility, bacteria, etc.. Water left to its own loose makeup in diesel fuel is like playing Russian Roulette..
George

[TDIwyse]

Isn't the saturation point of No. 2 diesel around 60 ppm at room temp? IIRC in a different thread Racor said the Aquabloc seperated emulsified and free water, but not saturated water. So, if the KF is measuring saturated water in diesel would it not make sense that the level of water was the same pre and post filter?

[Racor]

TDIwyse is correct.

Approximate dissolved water saturation in diesel fuel at:

100F = 155 ppm by volume
75F = 102 ppm
50F = 67 ppm

There is no practical way to remove dissolved water. It is not an emulsion or small drops. Dissolved water concentration varies with air humidity and temperature. KF titration sees all the water, including dissolved. There is no evidence that dissolved water damages injection components.

[ 03-21-2003: Message edited by: Racor ]</p>

[george morrison]

To reiterate: all of our 'before & after' fuel analysis testing done on Duramax (and 6.5TD's) fuel system OEM, resulted in absolutely no reduction in total water. KF water 65 ppm in, 65 ppm water after OEM.. (with 60 ppm being a fairly representative average during summer/fall).
The analysis results are for Duramax locations in Columbus, Ohio, Florida, Colorado, Indiana and New Jersey.. A fair representatation. There were no anomalies: all results were within 5 ppm water KF of one another..
George Morrison

[Racor]

I agree that 65 ppm went in and 65 ppm came out.

65 ppm is background, dissolved water, and it is nearly impossible(and unnecessary)to remove it.

Again, diesel fuel, like air, has humidity and a saturation point.

No fuel filter can remove water that exists below the saturation point of the fuel. Once the saturation point is reached, you have free water and all the associated problems.

Your 65 ppm fuel is dry as a bone.

[george morrison]

Ay, but therein lies the rub. (or the galling, as it were).. So, fuel at 85 degrees with 70 ppm of entrained water passes through the fuel filter then the owner shuts down and lets sit overnight. The system temperature drops down to 35 degrees. Stagnent fuel, mother nature, gravity, now saturation point is lowered to 50 ppm. The water that was previously being held in suspension now begins to settle: in our fuel pump.. Free water, start up, piston gall.. It is that simple and unfortunately, that expensive..
Same situation, this time with an agressive water emulsifer that *prevents* the free water from settling even though we have lowered the apparent saturation point. Now the water does not react as normal as it is "locked" in suspension, surrounded by a protective lubricating shield.
This is what emulsifying water via fuel additization is all about
George