JP-8
Encyclopedia
JP-8, or JP8 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.
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, limiting its use to aircraft carriers and other situations where the danger of fire is greatest.
Outside of powering aircraft, JP-8 is used as a fuel for heater
s, stove
s, tank
s, by the U.S. military 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 inhibitor
s, lubricant
s, and antistatic agent
s, 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
.
s 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 following ignition delay because 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 engine
s can be the increased wear in outlet valve seats in the cylinder heads, because a minimum content of sulfur is not specified in MIL-DTL-83133G. Sulfur in fuels contributes normally to build up damping soot layers in these valve seats. According to the notes in this standard it is intended to install a value for the cetane index
in one of the next releases.
Workers have complained of smelling and tasting JP-8 for hours after exposure. As JP-8 is less volatile, it remains on the contaminated surfaces for longer time, increasing the risk of exposure.
, 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 Boeing
aircraft operated by KLM, and in police helicopters in Tampa, Florida
. JP-8+100 is also used for Canadian Forces CP-140 Aurora & CC-130 Hercules aircraft.
Jet fuel
Jet fuel is a type of aviation fuel designed for use in aircraft powered by gas-turbine engines. It is clear to straw-colored in appearance. The most commonly used fuels for commercial aviation are Jet A and Jet A-1 which are produced to a standardized international specification...
, 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
Kerosene
Kerosene, sometimes spelled kerosine in scientific and industrial usage, also known as paraffin or paraffin oil in the United Kingdom, Hong Kong, Ireland and South Africa, is a combustible hydrocarbon liquid. The name is derived from Greek keros...
-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
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
JP-5 or JP5 is a yellow, kerosene-based jet fuel developed in 1952 for use in aircraft stationed aboard aircraft carriers, where the risk from fire is particularly great. JP-5 is a complex mixture of hydrocarbons, containing alkanes, naphthenes, and aromatic hydrocarbons that weighs and has a...
. JP-5 has an even higher flash point of > 60 °C (140 °F), but also a higher cost, limiting its use to aircraft carriers and other situations where the danger of fire is greatest.
Outside of powering aircraft, JP-8 is used as a fuel for heater
Heater
A heater is an object that emits heat or causes another body to achieve a higher temperature. In a household or domestic setting, heaters are usually appliances whose purpose is to generate heating...
s, stove
Stove
A stove is an enclosed heated space. The term is commonly taken to mean an enclosed space in which fuel is burned to provide heating, either to heat the space in which the stove is situated or to heat the stove itself, and items placed on it...
s, tank
Tank
A tank is a tracked, armoured fighting vehicle designed for front-line combat which combines operational mobility, tactical offensive, and defensive capabilities...
s, by the U.S. military as a replacement for diesel fuel in the engines of nearly all tactical ground vehicles and electrical generators,
and as a coolant
Coolant
A coolant is a fluid which flows through a device to prevent its overheating, transferring the heat produced by the device to other devices that use or dissipate it. An ideal coolant has high thermal capacity, low viscosity, is low-cost, non-toxic, and chemically inert, neither causing nor...
in engines and some other aircraft components. The use of a single fuel greatly simplifies logistics.
JP-8 is formulated with icing inhibitor
Fuel System Icing Inhibitor
Fuel system icing inhibitor is an additive to aviation fuels that prevents the formation of ice in fuel lines. FSII is sometimes referred to by the registered, genericized trademark Prist. Jet fuel can contain a small amount of dissolved water that does not appear in particulate form...
, corrosion inhibitor
Corrosion inhibitor
A corrosion inhibitor is a chemical compound that, when added to a liquid or gas, decreases the corrosion rate of a material, typically a metal or an alloy. The effectiveness of a corrosion inhibitor depends on fluid composition, quantity of water, and flow regime...
s, lubricant
Lubricant
A lubricant is a substance introduced to reduce friction between moving surfaces. It may also have the function of transporting foreign particles and of distributing heat...
s, and antistatic agent
Antistatic agent
An antistatic agent is a compound used for treatment of materials or their surfaces in order to reduce or eliminate buildup of static electricity generally caused by the triboelectric effect. Its role is to make the surface or the material itself slightly conductive, either by being conductive...
s, and less benzene
Benzene
Benzene is an organic chemical compound. It is composed of 6 carbon atoms in a ring, with 1 hydrogen atom attached to each carbon atom, with the molecular formula C6H6....
(a carcinogen
Carcinogen
A carcinogen is any substance, radionuclide, or radiation that is an agent directly involved in causing cancer. This may be due to the ability to damage the genome or to the disruption of cellular metabolic processes...
) and less n-hexane
Hexane
Hexane is a hydrocarbon with the chemical formula C6H14; that is, an alkane with six carbon atoms.The term may refer to any of four other structural isomers with that formula, or to a mixture of them. In the IUPAC nomenclature, however, hexane is the unbranched isomer ; the other four structures...
(a neurotoxin
Neurotoxin
A neurotoxin is a toxin that acts specifically on nerve cells , usually by interacting with membrane proteins such as ion channels. Some sources are more general, and define the effect of neurotoxins as occurring at nerve tissue...
) 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
Solvent
A solvent is a liquid, solid, or gas that dissolves another solid, liquid, or gaseous solute, resulting in a solution that is soluble in a certain volume of solvent at a specified temperature...
.
Problems
When used in highly supercharged diesel engineDiesel engine
A diesel engine is an internal combustion engine that uses the heat of compression to initiate ignition to burn the fuel, which is injected into the combustion chamber...
s 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 following ignition delay because cetane index
Cetane index
Cetane index is used as a substitute for the cetane number of diesel fuel. The cetane index is calculated based on the fuel's density and distillation range . There are two methods used, ASTM D976 and D4737. The older D976, or "two-variable equation" is outdated and should no longer be used for...
is not specified in MIL-DTL-83133G to 40 or higher. Because lubricity
Lubricity
Lubricity is the measure of the reduction in friction of a lubricant. The study of lubrication and mechanism wear is called tribology.-Measurement of 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 engine
Diesel engine
A diesel engine is an internal combustion engine that uses the heat of compression to initiate ignition to burn the fuel, which is injected into the combustion chamber...
s can be the increased wear in outlet valve seats in the cylinder heads, because a minimum content of sulfur is not specified in MIL-DTL-83133G. Sulfur in fuels contributes normally to build up damping soot layers in these valve seats. According to the notes in this standard it is intended to install a value for the cetane index
Cetane index
Cetane index is used as a substitute for the cetane number of diesel fuel. The cetane index is calculated based on the fuel's density and distillation range . There are two methods used, ASTM D976 and D4737. The older D976, or "two-variable equation" is outdated and should no longer be used for...
in one of the next releases.
Workers have complained of smelling and tasting JP-8 for hours after exposure. As JP-8 is less volatile, it remains on the contaminated surfaces for longer time, increasing the risk of exposure.
Variants
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 surfactantSurfactant
Surfactants are compounds that lower the surface tension of a liquid, the interfacial tension between two liquids, or that between a liquid and a solid...
, metal deactivator
Metal deactivator
Metal deactivators, or metal deactivating agents are fuel additives and oil additives used to stabilize fluids by deactivating metal ions, mostly introduced by the action of naturally occurring acids in the fuel and acids generated in lubricants by oxidative processes with the metallic parts of...
, and an antioxidant
Antioxidant
An antioxidant is a molecule capable of inhibiting the oxidation of other molecules. Oxidation is a chemical reaction that transfers electrons or hydrogen from a substance to an oxidizing agent. Oxidation reactions can produce free radicals. In turn, these radicals can start chain reactions. When...
, and was introduced in 1994 to reduce choking and fouling in engine fuel systems. Commercially, this additive is used in Boeing
Boeing
The Boeing Company is an American multinational aerospace and defense corporation, founded in 1916 by William E. Boeing in Seattle, Washington. Boeing has expanded over the years, merging with McDonnell Douglas in 1997. Boeing Corporate headquarters has been in Chicago, Illinois since 2001...
aircraft operated by KLM, and in police helicopters in Tampa, Florida
Tampa, Florida
Tampa is a city in the U.S. state of Florida. It serves as the county seat for Hillsborough County. Tampa is located on the west coast of Florida. The population of Tampa in 2010 was 335,709....
. JP-8+100 is also used for Canadian Forces CP-140 Aurora & CC-130 Hercules aircraft.
See also
- JP-1JP-1JP-1 was an early jet fuel, specified in 1944 by the U.S. government . It was a pure kerosene fuel with high flash point and a freezing point of −60 °C...
- JP-4JP-4JP-4, or JP4 was a jet fuel, specified in 1951 by the U.S. government . It was a 50-50 kerosene-gasoline blend. It has lower flash point than JP-1, but was preferred because of its greater availability. It was the primary U.S. Air Force jet fuel between 1951 and 1995. Its NATO code is F-40...
- JP-5JP-5JP-5 or JP5 is a yellow, kerosene-based jet fuel developed in 1952 for use in aircraft stationed aboard aircraft carriers, where the risk from fire is particularly great. JP-5 is a complex mixture of hydrocarbons, containing alkanes, naphthenes, and aromatic hydrocarbons that weighs and has a...
- JP-6JP-6Jet Propellant 6 is a type of jet fuel developed for General Electric YJ93 jet engine of the XB-70 Valkyrie supersonic aircraft. JP-6 was similar to JP-5 but with a lower freezing point and improved thermal oxidative stability...
- JP-7JP-7JP-7 is a jet fuel developed by the U.S. Air Force for use in supersonic aircraft because of its high flash point and thermal stability. It is the fuel used in the Pratt & Whitney J58 engines, used in the Lockheed SR-71 Blackbird. The air compression of Mach 3+ cruising flight generates very high...
- JP-8
- JPTSJPTSJPTS stands for Jet Propellant Thermally Stable , and was created specifically for the Lockheed U-2 reconnaissance aircraft....
- Jet fuelJet fuelJet fuel is a type of aviation fuel designed for use in aircraft powered by gas-turbine engines. It is clear to straw-colored in appearance. The most commonly used fuels for commercial aviation are Jet A and Jet A-1 which are produced to a standardized international specification...
- Aviation fuelAviation fuelAviation fuel is a specialized type of petroleum-based fuel used to power aircraft. It is generally of a higher quality than fuels used in less critical applications, such as heating or road transport, and often contains additives to reduce the risk of icing or explosion due to high temperatures,...
External links
- MIL-DTL-83133 technical specifications (includes JP-8) United States Defense Energy Support Center
- MIL-DTL-46162 referee fuel Diesel and JP-8 United States Defense Energy Support Center
- Current United States Department of Defense Fuel Prices