Talk:JP-7

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If the flashpoint is only 60 degrees Celsius then there's no way a lit match will be extinguished in JP-7 (see the claim in the SR-71 Blackbird article. Which is wrong? Lisiate 22:52, 7 Jun 2005 (UTC)

In the book "Skunk_works", Ben Rich makes the claim that a lit match dropped on the Blackbird's fuel will simply go out. I'm fairly certain he specifically called it JP-7, but I don't remember if he mentioned its flashpoint. I'll check on that tonight...

OK:

"[...] five noninsulated fuselage and wing tanks that would heat up during supersonic flight to about 350 degrees; we turned to Shell to develop a special, safe, high-flash-point fuel that would not vaporize or blow up under tremendous heat and pressure. A lighted match dropped on a spill would not set it ablaze. The fuel remained stable at enormous temperature ranges: the minus 90 degrees experienced when a KC-135 tanker pumped fuel into the Blackbird at 35,000 feet, and the 350 degrees by the time the fuel fed the engines." (Skunk Works, p. 205)

"The fuel, JP-7, has a kerosene base and such an extremely high flash point that the only way to ignite it was by using a chemical additive called tetraethyl borane, injected during the start prodecure." (Skunk Works, p. 218)

If it's "stable" at 350 degrees, I'm guessing it didn't have a flashpoint of 60F.  :-) What's the source on that number, I wonder?

On second thought, I take it back. I reread Flashpoint, and realized I didn't (don't?) really understand that -- perhaps it's possible to have a 60C flashpoint but not be ignited by a match. Chemists feel free to help me out here.  :-)

Cheers for your response. Looking at the Flash point article, apparently there is a distinction between the Flash Point, where the fuel will ignite when exposed to a spark, and 'Fire Point' where the fuel will continue to burn Perhaps this is the answer here? That would seem to fit with the stability at 350 F (around 150 C?) in the absence of a spark anyway. Lisiate 21:52, 9 Jun 2005 (UTC)

I'm not a chemist, but I do work with aviation fuels, and I might be able to offer some insight here. Flashpoint refers to the temperature at which a fuel will give off enough vapours to generate a flammable fuel/air mixture. Above the flashpoint, any spark, no matter how small, can ignite the fuel. A common source of confusion is the idea that liquids can burn (they cannot, only the vapours can). Below the flashpoint a fuel stays liquid and is much more difficult to ignite. To ignite a fuel in this state, either the temperature must be raised 'til it vapourizes, or the fuel must be aerosolized into the air. A match will not provide sufficient heat to generate the vapours that it could ignite, therefore the bucket won't blow up. On another note, the fire point is related to the flashpoint because at the fire point, the flames from the fuel can generate enough heat to sustain the generation of flammable vapours from a fuel even if the ambient temperature is lower than the flashpoint. Reading back on this, it seems heavy and confusing. Leave a note if you'd like me to try and explain something better. -Lommer | ^talk 20:50, 18 August 2005 (UTC)

[edit] Single malt scotch

I seem to remember an anecdote that said that JP-7 was more expensive per volume than the finest single-malt scotch whiskey. Does this have a place in the article? Rusty 00:58, 20 August 2006 (UTC)