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JP-8

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For the Roland synthesizer, see Roland JP-8000.

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-1, but with the addition of corrosion inhibitor and anti-icing additives.

It was first introduced at NATO bases in 1978. Its NATO code is F-34.

Usage

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The United States Air Force replaced JP-4 with JP-8 completely by the end of 1995, to use a less flammable, less hazardous fuel for better safety and combat survivability.[1] In 2014, they completed the process of converting all JP-8 installations within the United States to instead use commercial Jet A-1 fuel with additional additives.[2]

JP-8 is formulated with an icing inhibitor, corrosion inhibitor–lubricants, and antistatic agents, and contains less benzene (a carcinogen) and 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.

The United States Navy uses a similar formula, JP-5. JP-5 has an even higher flash point of > 140 °F (60 °C), but also a higher cost. The U.S. Navy Seabees use JP-8 in construction and tactical equipment.

Single-fuel concept

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JP-8 was specified in 1990 by the U.S. government as a replacement for government diesel fueled vehicles. This is in the wider context of the 1986 NATO Single-Fuel Concept agreement, in which F-34 (JP-8) is to replace F-54 (diesel fuel) in land vehicles and F-40 (JP-4) in land-based turbine aircraft to simplify logistics.[3] It is also used as coolant in engines and some other aircraft components.

Beyond use in vehicles from trucks to tanks[4] to planes, JP-8 is used in U.S. Army heaters and stoves.[5][6]

Problems

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Diesel problems

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When used in highly turbocharged diesel engines with the corresponding low compression ratio (e.g. 14:1 or lower), 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 maximum sulfur content 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.[citation needed] MIL-DTL-83133J sets the maximum sulfur content at 0.30%. It however only requires a cetane number of 40 after addition of FT-SPK (synthetic jet fuel).[7]

The use of jet fuel in diesel engines has caused some minor issues, none of which were discovered in the Fort Bliss test with JP-8. During Desert Shield and Desert Storm, commercial Jet A1 was used as the single-fuel and failed engines with Stanadyne fuel-injection pumps missing an elastomer insert retrofit.[8] Other than that, JP-8 slightly reduces torque and fuel economy due to its lower density and viscosity compared to diesel fuel. Engine modification can offset this issue.[9]

Health concerns

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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.[10]

In 2001, Texas Tech University's Institute of Environmental and Human Health and the United States Air Force conducted an 18-month study of the health effects of JP-8 on 339 active duty personnel at six US Air Force installations. The study found that Air Force workers who were exposed to JP-8 were no more likely to seek medical attention than workers who were not exposed to JP-8 on the job.[11]

Variants

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JP-8+100 (F-37) is a variant of JP-8 augmented with the additive Spec-Aid 8Q462, also known as Aeroshell Performance Additive 101, created by BetzDearborn (now GE Betz).[12] The additive increases the thermal stability of JP-8 by 100°F (56°C), hence the designation "+100". Spec-Aid 8Q462 was introduced in 1994 to reduce choking and fouling in engine fuel systems and is a combination of a surfactant, metal deactivator, and an antioxidant. It is added to JP-8 at a ratio of 256 ppm to create JP-8+100, at an added cost of $5 per 1000 gallons of fuel.[13] 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, CF-18 Hornet and the CC-115 Buffalo.

F-35 is a variant without icing inhibitor. The only required additive is a static dissipater.[7]

JP-8+100LT is a variant of JP-8+100, with additives to facilitate low-temperature performance. It is considered as a logistically friendly low-cost replacement of the JPTS fuel for the Lockheed U-2 airplane.[13]

F-24 is commercial Jet A fuel (ASTM D1655) with the additive package required for JP-8 (SDA, CI/LI, FSII) added by the military.[14] The intention is to lower costs by using commercially-available fuel. The resulting fuel has identical properties to JP-8, save for a higher freezing-point specification.[15] The U.S. military has switched to F-24 in domestic (excluding Alaska) sites in 2012.[16] In 2018, it was found that the F-24 mixture could deteriorate during transport causing much reduced thermal stability, but addition of the +100 (8Q462) additive was enough to salvage degraded fuel.[17]

F-27 is F-24 with the +100 additive package.[14]

JP-8+225 is a planned variant of JP-8 that increases thermal stability by 225 °F (125 °C). Such a fuel would match the thermal stability of JP-7 and become a lower-cost replacement should it exist.[18]

See also

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References

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  1. ^ "The History of Jet Fuel". archive.org. BP. 18 October 2012. Archived from the original on October 18, 2012. Retrieved 21 December 2014.
  2. ^ West, Brad (October 31, 2014). "Air Force completes historic fuel conversion". United States Air Force. Archived from the original on 2024-12-24. Retrieved 2025-01-01.
  3. ^ "Chapter 15: Fuels, Oils, Lubricants and Petroleum Handling Equipment: Military Fuels and the Single Fuel Concept". Retrieved 19 May 2023.
  4. ^ the M1 Abrams series of battle tanks uses JP fuel in its gas turbine engine
  5. ^ Modern Burner Units Archived 2011-07-16 at the Wayback Machine, 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
  6. ^ Babington Airtronic Burner Archived 2014-02-26 at the Wayback Machine burns JP-8 and other distillate fuels, and is the current common heat source for Marine Corps food service equipment.
  7. ^ a b MIL-DTL-83133J.
  8. ^ "The Reality of the Single-Fuel Concept". www.globalsecurity.org.
  9. ^ McKee, Heather; Fernandes, Gerald; Fuschetto, Jerry; Filipi, Zoran; Assanis, Dennis (2005-12-07). "Impact of Military JP-8 Fuel on Heavy Duty Diesel Engine Performance and Emissions #ADA573594".
  10. ^ Day, Dwayne A. "Aviation Fuel". U.S. Centennial of Flight Commission. Retrieved 21 December 2014.
  11. ^ Ronald K. Kendall; Ernest Smith; Leslie B. Smith; Roger L. Gibson (August 2001). "JP-8 Final Risk Assessment" (PDF). Texas Tech University. Archived (PDF) from the original on March 27, 2020. Retrieved April 18, 2021.
  12. ^ MIL-DTL-83133F DETAIL SPECIFICATION TURBINE FUEL, AVIATION, KEROSENE TYPE, JP-8 (NATO F-34), NATO F-35, and JP-8+100 (NATO F-37). From https://quicksearch.dla.mil/Transient/19C031269152438C816A666C97F37F4A.pdf
  13. ^ a b Simms, Christian G. (March 2001). "JP-8+100LT: A low cost replacement of JPTS as the primary fuel for the U-2 aircraft?" (PDF). Defense Technical Information Center. Archived (PDF) from the original on September 27, 2013.
  14. ^ a b MIL-STD-3004-1 w/CHANGE 1, available from https://quicksearch.dla.mil/Transient/230B5DB336074B18A1E558D105636331.pdf
  15. ^ "USMC POLICY ON CONVERTING CONUS AVIATION AND GROUND/TACTICAL EQUIPMENT FROM JP-8 TO F-24". www.marines.mil.
  16. ^ Paul J. Kern; Walker Mills; Erik Limpaecher; Matt Santoli; Ben Flanagan (29 June 2021). "An Albatross Around the US Military's Neck: The Single Fuel Concept and the Future of Expeditionary Energy". Modern War Institute.
  17. ^ Morris, Robert W. Jr; Shardo, James R.; Marcum, Grady; Lewis, William K.; Wrzesinski, Paul J.; Bunker, Christopher E. (2018-01-01). "Characterization of an On-Spec, Commercial Grade, Jet A and A Near-Off-Spec Military F-24; Evaluation of +100 Thermal Stability Package". Defense Technical Information Center.
  18. ^ Edwards, Tim (13 July 1998). Prospects for JP-8+225, a stepping stone to JP-900. 34th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit. doi:10.2514/6.1998-3532.
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