I'm looking at a system safety practice analysis we're doing and have a question - if a pool of diesel fuel is subjected to a spark, will it ignite usually? I seem to remember diesel fuel being much more difficult to burn in a situation like this than gasoline. Also, what if it were spraying out of a hole in a pressurized pipe and saw the spark? What about an open flame? Thanks, guys!
Chris

 

Diesel fuel is unlikely to be ignited by a spark, the flash point is too high. In your scenario of spraying out of a cracked pipe, the open flame would probably get it going, but a spark probably wouldn't do anything.

 

Great - thanks for the info.
Chris

 

It seems like spraying in a mist, it would be more likely to ignite. I have a fuel oil tank I've been slowly emptying. Pour a couple gallons on the trash pile when I'm ready for a burn. Usually takes more than a match to get it going. Still have to use news paper or something as an open flame. I'd also wonder about another, continuous type of heat source, such as hot metal, or electrical. Something that wouldn't necessarily be "doused" when the fuel hits it. Hope this helps ya.

 

Generally, the vapous of fuel, whether gasonline or diesel are much more flammable than the liquid itself.

 

I have put matches out in a pool of diesel. the best thing is to get a small amount and play with it. set up some experaments and test each of them. Post the results back here...

 

I like playing with fire 8) I wish we could have a Cummins that runs on every fuel. that way if gas is a lot cheaper like it is here in Ohio 1.69 for diesel and 1.44 for gas you can run the gas.
DM01

 

Well, actually only gas can burn. Liquid can't burn. So we need to produce a vapour to ignite the stuff. If a substance has a high vapor pressure at a given temperature it will form a vapour or steam on its own and will be easily inflammable. Under normal environment temps diesel won't have much of a vapour above it so it's safe to extinguish matches in a pool of diesel. ( I don't mean to do this all the time, just under controlled experimental conditions with proper safety gear etc !!!! ) - Whereas a burning match close to gas will ignite the vapor above the fluid and off we go. If you do the same experiment with a match , but preheat diesel to let's say 80C (176F ) you'll see that there is enough vapor to be ignited and it will burn good. So smoking while refueling your CTD with that canister that has baked on the bed in the sun in Texas......

Just my 2c

AlpineRAM

 

Nerd... : :P

 

[quote author=Hoss link=board=10;threadid=21115;start=0#msg199366 date=1066767296]
Nerd... : :P
[/quote]

Hoss -need I say more

 

I have to back Alpine on this one. There are a couple points that we're concerned with when talking about flammable items,...lower flash point, burn point, and upper flash point. The lower flash point is where there's enough vapor to create a flame when exposed to an ignition source, but it will only burn like a flash, then extinguish because all the available vapor is burned. The burn point is the temperature at which there is enough vapor being created to support ongoing combustion when an ignition source is introduced. The upper flash point is the point at which there is so much vapor being produced that when exposed to an ignition source the oxygen is the limiting factor, not the fuel vapor.

Lower flash point for gasoline is approx -40 F, and about 140 F for diesel.

-SFB

 

[quote author=dodgeman01 link=board=10;threadid=21115;start=0#msg198826 date=1066659176]
I like playing with fire[/quote]I remember my first time at the Navy FireFighting School in San Diego. That jet fuel was a beautiful purple geyser coming out of the floor when they opened the valve..... til they tossed the torch onto it.

 

Thanks shortfieldbreak- in discussions like these I really notice that english is not my mother tongue.

AlpineRAM

Hehe, and Hoss hasn't a half as good excuse ;D