Cold filter plugging point (CFPP) is the lowest temperature, expressed in degrees Celsius (°C), at which a given volume of
diesel type of
fuel
A fuel is any material that can be made to react with other substances so that it releases energy as thermal energy or to be used for work. The concept was originally applied solely to those materials capable of releasing chemical energy bu ...
still passes through a standardized
filtration
Filtration is a physical separation process that separates solid matter and fluid from a mixture using a ''filter medium'' that has a complex structure through which only the fluid can pass. Solid particles that cannot pass through the filte ...
device in a specified time when cooled under certain conditions. This test gives an estimate for the lowest temperature that a fuel will give trouble free flow in certain fuel systems. This is important as in cold
temperate countries
In geography, the temperate climates of Earth occur in the middle latitudes (23.5° to 66.5° N/S of Equator), which span between the tropics and the polar regions of Earth. These zones generally have wider temperature ranges throughout ...
, a high cold filter plugging point will clog up vehicle engines more easily.
The test is important in relation to the use of additives that allow spreading the usage of
winter diesel at temperatures below the cloud point. The tests according to
EN 590 EN 590 is a standard published by the European Committee for Standardization that describes the physical properties that all automotive diesel fuel must meet if it is to be sold in the European Union and several other European countries.
Based on ...
show that a CloudPoint of +1 °C can have a CFPP −10 °C. Current additives allow a CFPP of −20 °C to be based on diesel fuel with a CloudPoint of −7 °C.
The trustworthiness of the EN 590 have been criticized as being too low for modern diesel motors – the German
ADAC
ADAC, officially the Allgemeiner Deutscher Automobil-Club (), is Europe's largest motoring association. ADAC is the largest club (Verein) in Germany with around 21 million members. It would be more aptly described today as an individual m ...
has run a test series on
customary winter diesel in a cold chamber. All diesel brands did exceed the legal minimum by 3 to 11 degrees in the laboratory according to the legal DIN test. One of the real diesel motors however stopped working even before the legal minimum was reached, presumably due to an undersized
filter heater. Notably the experiments did not show a direct correlation between the CFPP value of the mineral oil and the cold start capability of the diesel motors – hence the automobile club suggest the creation of a new test standard.
Test method
The ASTM no. for the test method to define cold filter plugging point is ASTM D-6371.
See also
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Cloud point
In liquids, the cloud point is the temperature below which a transparent solution undergoes either a liquid-liquid phase separation to form an emulsion or a liquid-solid phase transition to form either a stable sol or a suspension that settles a ...
*
Petroleum
Petroleum, also known as crude oil, or simply oil, is a naturally occurring yellowish-black liquid mixture of mainly hydrocarbons, and is found in geological formations. The name ''petroleum'' covers both naturally occurring unprocessed crude ...
*
Pour point
The pour point of a liquid is the temperature below which the liquid loses its flow characteristics.
It is defined as the minimum temperature in which the oil has the ability to pour down from a beaker. In crude oil a high pour point is generally ...
References
External links
BP information
{{physical-chemistry-stub
Chemical properties
Fuel technology