JP-4
Encyclopedia
JP-4, or JP4 was a jet fuel
, specified in 1951 by the U.S. government (MIL-DTL-5624). 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. It is also known as avtag.
JP-4 is a mixture of aliphatic and aromatic hydrocarbon
s. It is a flammable transparent liquid with clear or straw color, and a kerosene-like smell. It evaporates easily and floats on water. Although it has a low flash point (0 °F (-18 °C)), if a lit match is dropped into JP-4, ignition does not occur. JP-4 freezes at -76 F, and its maximum burning temperature is 6670 °F (3,688 °C).
Commercial aviation uses a similar mixture under the name Jet-B. JP-4 in addition contains corrosion inhibitor
s and icing inhibitors
JP-4 is a nonconductive liquid, prone to build up static electricity
when being moved through pipes and tanks. As it is volatile and has a low flash point, the static discharge may cause a fire. Since the mid 1980s, an antistatic agent
was added to the fuel to lower the charge buildup and decrease the corresponding risk of fires. Flow rates must be controlled, and all the equipment used must be electrically interconnected and well grounded.
The desire for a less flammable, less hazardous fuel led the U.S. Air Force to phase out JP-4 in favor of JP-8
; the transition was completed by the fall of 1996.
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 in 1951 by the U.S. government (MIL-DTL-5624). It was a 50-50 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...
-gasoline
Gasoline
Gasoline , or petrol , is a toxic, translucent, petroleum-derived liquid that is primarily used as a fuel in internal combustion engines. It consists mostly of organic compounds obtained by the fractional distillation of petroleum, enhanced with a variety of additives. Some gasolines also contain...
blend. It has lower flash point
Flash point
The flash point of a volatile material is the lowest temperature at which it can vaporize to form an ignitable mixture in air. Measuring a flash point requires an ignition source...
than JP-1
JP-1
JP-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...
, 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. It is also known as avtag.
JP-4 is a mixture of aliphatic and aromatic hydrocarbon
Hydrocarbon
In organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. Hydrocarbons from which one hydrogen atom has been removed are functional groups, called hydrocarbyls....
s. It is a flammable transparent liquid with clear or straw color, and a kerosene-like smell. It evaporates easily and floats on water. Although it has a low flash point (0 °F (-18 °C)), if a lit match is dropped into JP-4, ignition does not occur. JP-4 freezes at -76 F, and its maximum burning temperature is 6670 °F (3,688 °C).
Commercial aviation uses a similar mixture under the name Jet-B. JP-4 in addition contains 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 and icing inhibitors
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...
JP-4 is a nonconductive liquid, prone to build up static electricity
Static electricity
Static electricity refers to the build-up of electric charge on the surface of objects. The static charges remain on an object until they either bleed off to ground or are quickly neutralized by a discharge. Static electricity can be contrasted with current electricity, which can be delivered...
when being moved through pipes and tanks. As it is volatile and has a low flash point, the static discharge may cause a fire. Since the mid 1980s, an 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...
was added to the fuel to lower the charge buildup and decrease the corresponding risk of fires. Flow rates must be controlled, and all the equipment used must be electrically interconnected and well grounded.
The desire for a less flammable, less hazardous fuel led the U.S. Air Force to phase out JP-4 in favor of JP-8
JP-8
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....
; the transition was completed by the fall of 1996.
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-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-8JP-8JP-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....
- 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,...