is DEF fluid flammable?

I've was a diesel mechanic for 15 years before I started driving. Pretty sure I know what I'm talking about. DEF is mostly H2O...the other stuff in it is primarily to keep it from freezing. Running a couple of gallons of water to get you out of a mess hasn't ever hurt any trucks I know of...especially when you top if off with 16-20 gallons of DEF when you get to a pump.

Why run out? Because we only have specific places that we are allowed to buy it. Those places are closed at night and on the weekends. When you share a truck with an incompetent nut job that is too lazy to top it off on his shift...you have to make something work.

 

15 years ago as a mechanic you didn't really have to deal with DEF. If someone does not believe me then consult the engine manufacturers about addiing water to the DEF tank. DEF needs to be a certain percentage around 32%, the rest yes is water. Distiller or demineralized water. The contaminants in normal tap water WILL cause failure of the SCR.

Hey if you run out of diesel you can mix gasoline and motor oil and it will run right? No problems there either I'm sure. Radiator empty? Just put a couple cases of Coca Cola in it, it will get you to your next stop, not a problem. Just because you CAN do something does not mean it is a good idea to do so.

 

No sense in going out of your way to be a smarta$$. I simply posted what I have personally done...a few times on 2 different trucks I drove well beyond 500K miles and it didn't hurt a thing. Nowhere did I say this was something practiced on a regular basis. Only when there was no other option. Don't spin it.

And BTW, I was still turning wrenches when DEF became mandatory. I said I did it for 15 years...not 15 years ago. I've worked on (serviced, repaired and replaced) my share of DPF's, DEF systems and parts.

 

DEF is approximately 2/3 water, and 1/3 urea. Yes i know it is actually a bit more than 2/3 water, but close enough. Urea can be actual animal urine from horses, pigs, cows etc. But is more commonly made synthetically. It is not flammable, but does freeze easily. It is corrosive as is all urine, ever look closely at an older horse trailer? The horses peeing caused the corrosion you see. You can freeze DEF and thaw it out without harming it. And while it doesn't last forever, it has a long shelf life so don't worry about buying it in bulk.

 

I never used DEF. Thankfully I got out before I had to. I take Wikipedia with a grain of salt, but this article seems right to me. WIKIPEDIA DEF ARTICLE.

 

Urea is commonly used as a fertilizer, it replaces ammonia nitrate as fertilizer, as it is cheaper. I know a farmer that makes his own DEF, mixing liquid urea fertilizer with water, for pennies a gallon. I wouldn't do it myself, but he's been doing it a couple of years with no ill effects.

 

Thats how the DEF we haul every once in a while is made. They mix granulated urea fertilizer and warm water. Ive hauled in consecrations up to 60% urea for a coal power plant. Ive also hauled urea fertilizer in a pneumatic trailer and blown it into at tank of 200 degree water. Had to go slow enough as to not cool the water off below 140 degrees. It was a strange process.

 

DEF is water and ammonia. Water don't burn last time I checked.

 

It feels flammable when you get it on your skin and it starts to dry out.

 

Someone needs to check again on the makeup of DEF.