JP-8

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JP-8, or JP8 (for "Jet Propellant 8") is a jet fuel, specified and used widely by the US military. It is specified by MIL-DTL-83133 and British Defence Standard 91-87, and similar to commercial aviation's Jet-A.

A kerosene-based fuel, JP-8 is projected to remain in use at least until 2025. It was first introduced at NATO bases in 1978. Its NATO code is F-34.

Usage[edit]

It was specified in 1990 by the U.S. government as a replacement for government diesel fueled vehicles.

The U.S. Air Force replaced JP-4 with JP-8 completely by the fall of 1996, to use a less flammable, less hazardous fuel for better safety and combat survivability.

The U.S. Navy uses a similar formula, JP-5. JP-5 has an even higher flash point of > 60 °C (140 °F), but also a higher cost.

Apart from powering aircraft, JP-8 is used as a fuel for heaters, stoves,[1][2] tanks,[3] by the U.S. military and its NATO allies as a replacement for diesel fuel in the engines of nearly all tactical ground vehicles and electrical generators, and as a coolant in engines and some other aircraft components. The use of a single fuel greatly simplifies logistics.

JP-8 is formulated with icing inhibitor, corrosion inhibitors, lubricants, and antistatic agents, and less benzene (a carcinogen) and less n-hexane (a neurotoxin) than JP-4. However, it also smells stronger than JP-4. JP-8 has an oily feel to the touch, while JP-4 feels more like a solvent.

Problems[edit]

When used in highly supercharged diesel engines with the corresponding low compression ratio of about only 14:1 or below, JP-8 causes troubles during cold start and idling due to low compression temperatures and subsequent ignition delay because the cetane index is not specified in MIL-DTL-83133G to 40 or higher. Because lubricity to the BOCLE method is not specified in MIL-DTL-83133G, modern common-rail diesel engines can experience wear problems in high-pressure fuel pumps and injectors. Another problem in diesel engines can be increased wear to exhaust valve seats in the cylinder heads, because a minimum content of sulfur is not specified in MIL-DTL-83133G. Sulfur in fuel normally contributes to a build-up of soot layers on these valve seats. According to the notes in this standard, it is intended to include a cetane index value in one of the next releases.

Alternative Fuel Technologies, Redford, Michigan, (Founder, James McCandless) has successfully completed work, through an Army/SBIR (Small Business Innovation Research) grant (Phases 1 and 2), on mitigation of the valve-wear issue pursuant to using JP-8 fuel in common rail diesel engines, and recently received an award granted by The National Science Foundation, (http://www.sbir.gov/sbirsearch/detail/193600) and has been selected by NSF to work with them on fuel injection research for alternative fuels. The Army has recently selected Alternative Fuel Technology to move forward with Phase 3 SBIR after successful completion of the Phase 2 work. Phase 3 is commercialization. Contracts are currently being negotiated. https://www.armysbir.army.mil/Commercialization/PhaseIIIBrochures.aspx

Workers have complained of smelling and tasting JP-8 for hours after exposure. As JP-8 is less volatile than standard diesel fuel, it remains on the contaminated surfaces for longer time, increasing the risk of exposure.[4]

Variants[edit]

JP-8+100 (F-37) is a version of JP-8 with an additive that increases its thermal stability by 56°C (a difference of 100°F). The additive is a combination of a surfactant, metal deactivator, and an antioxidant, and was introduced in 1994 to reduce choking and fouling in engine fuel systems. Commercially, this additive is used in police helicopters in Tampa, Florida.[citation needed] JP-8+100 is also used for Canadian Forces CP-140 Aurora, CC-130 Hercules and the CC-115 Buffalo.

See also[edit]

References[edit]

  1. ^ Modern Burner Units, JP-8 is used by Army Food Service Specialists (cooks) to fuel MBUs, in accordance with U.S. Army Field Feeding Manual FM 10-23
  2. ^ Babington Airtronic Burner burns JP-8 and other distillate fuels, and is the current common heat source for Marine Corps food service equipment.
  3. ^ the M1 Abrams series of battle tanks uses JP fuel in its gas turbine engine
  4. ^ Day, Dwayne A. "Aviation Fuel". U.S. Centennial of Flight Commission. 

External links[edit]