Diesel Fuel & Storage Questions

[MadReferee]

</font><font color="blue" class="small">( I store my diesel fuel at the gas station. Let them keep the stuff. )</font>

Well you had better ask the station owner how much water is at the bottom of his underground storage tank. He should have a monitor that signals too much water and the more expensive monitors will tell how much. Typically there is 2" to 6" of water at the bottom. When I had my station that's what was in my tanks and I was told that is the norm. BTW, there is water at the bottom of gasoline storage tanks too.

 

[PineRidge]

MadReferee is correct. We used to stick underground tanks for water and chart the results. When it got to an extreme the water was then manually pumped from the tanks.

TC-40D SS web pictures click here

 

[cp1969]

And when he says, "an inch and a half" or "four inches" what do I ask next? "Well, how far is your pickup above the bottom of the tank?" or "Hey, how about them Republicans?" because either question has about the same relevance to me. Any given tank, on any given day, will have a different amount of water in it, up to the point where the pickup inhales it. I don't know about you, but I'm not going to look up the station owner and ask him how much water is in his tank every time I buy fuel.

But the bigger question is how does storing fuel at home change any of this? The fuel you get at home came from a storage tank, with water on the bottom, just like every storage tank has.

 

[PineRidge]

<font color="blue"> But the bigger question is how does storing fuel at home change any of this? The fuel you get at home came from a storage tank, with water on the bottom, just like every storage tank has.

</font>

My guess is that a good majority of folks that store large amounts of fuel at their business or home have some provision on the bottom of the storage tank to drain any water if and when it collects. And that coupled with a good quality water filter at the dispensing hose is as good as it gets IMHO.

TC-40D SS web pictures click here

 

[tomrscott]

Just had an interesting thought today that I wanted to share, on the subject of keeping water vapor out of a storage tank. The issue is that you have to have a vent so the tank can breathe with changing temperature, not to mention dispensing and filling.

Well, I am getting my air compressor ready to hook up to a new plasma cutter and the plasma rigs require very clean and dry air so there are a wide variety of pneumatic filters and water separators ranging from a few dollars to ten times that, and 50microns to 5microns of filtering.

So I'm sure you've guessed where I am going, why not put an inexpensive pneumatic air filter and water separator on the air breather port on a storage tank. That way if there is any water vapor in the air (I live in Oregon, so our air is damp once and awhile /forums/images/graemlins/grin.gif), it will mostly be trapped in the separator as the tank breathes.

Not to say that all the other techniques aren't a good idea too, but it would be pretty cheap to add just a bit more insurance. Should keep most of the water out of the tank in the first place, which should be a good thing.
/forums/images/graemlins/ooo.gif

 

[Junkman]

If the service stations pump pickup is located above the static water line, then you should be getting pure diesel fuel without water in it. I have heard the statement that all diesel fuel has water in it, then that must mean that there is water molecules that have bonded with the oil molecules. If this is so, then where did the expression "oil and water don't mix" come from. I test my home heating tank for water every few months, and I have not had any water problems in the tank since I switched oil companies. The old company had a lot of water in there fuel, but the new one is clean for the past 12 years. No water and no problems after the original water was pumped out. I use an electronic tester that is so sensitive that if you put your finger to your tongue and then touch the sensor, it will set off the signal.

 

[MadReferee]

From experience I know that ALL underground fuel storage tanks have some amount of water in them.

Now, as you say, if the pickup tube is below the static water line then you will be sucking water with your fuel. Also if you purchase just after a delivery truck put a few thousand gallons in the tank then you might get water too as the static water will be mixed with the fuel.

However, all underground tanks are required to have water sensors and water alarms. So unless the station owner is both blind and deaf he should never be pumping when the water level is too high.

 

[tomrscott]

I was specifically referring to the fact (I believe it is a fact) that any storage tank must have an air vent, and that when the relative humidity is high (dew at night, and changing weather...) and the tank is cooling, that water vapor will enter the tank through the air vent and may condense inside the tank and remain as water in the fuel.

It seems to me that a certain amount of this is inescapable. Maybe it isn't often a big problem, but it seems like, day after day, a little bit at a time, it would add up. Here in Oregon, we have lots of moisture all most year round, so I am more sensitive to it. Probably a bigger problem here than Arizona or Nevada. /forums/images/graemlins/ooo.gif

 

[cowboydoc]

I think you are making way more of that air vent. The vents on our tanks do not allow moisture in. Yours may be an older one or broken and possible allow water in. How long does your fuel sit before you use it?

 

[LBrown59]

Yes, you are correct about the giant cotton swabs. It really confused me when I was pulling into a car show a few years ago and a DOT cop asked me to stop in my diesel pickup. He then pulled out this giant cotton swab. (yeah, I was getting nervous, but not for the fuel reason ). It wasn't until after he'd run it down into my fuel tank on my pickup that he told me what he was looking for. Boy, was I relieved. He still had a whole box of those cotton swab looking things and I didn't want him doing any other probing!!

Dargo

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Just put an anti siphoning screen in the fuel filler neck of the tank.

No way to swab it then