COLD FILTER PLUGGING POINT (CFPP) OF DIESEL AND HEATING FUELS: D6371
(Equivalent Test Methods: IP 309 and EN 116)
EXPLANATION
The CFPP of a fuel is suitable for estimating the lowest temperature at which a fuel will give trouble-free flow in certain fuel systems. For diesel fuels used in European light duty trucks, the results are usually close to the temperature of failure in service except in some specific circumstances. Domestic heating installations are usually less critical and often operate satisfactorily at temperatures somewhat lower than those indicated by the test results. The difference in results obtained from the sample as received and after heat treatment at 45° C for 30 min can be used to investigate complaints of unsatisfactory performance under low temperature conditions.
This test method is applicable to distillate fuels including those containing a flow-improving or other additive intended for use in diesel engines and domestic heating installations.
TEST SUMMARY
Either manual or automated apparatus may be used. A sample is cooled under specified conditions and at intervals of 1 ° C, is drawn into a pipette under a controlled vacuum through a standardized wire mesh filter. As the sample continues to cool, the procedure is repeated for each 1 ° C below the first test temperature. The testing is continued until the amount of wax crystals that have separated out of the solution is sufficient to stop or slow down the flow so that the time taken to fill the pipet exceeds 60 s or the fuel fails to return completely to the test jar before the fuel has cooled by a further 1 ° C. The indicated temperature at which the last filtration was commenced is recorded as the CFPP.
TEST PRECISION
Repeatability: 1.76° C
Reproducibility: 0.102 (25 - X) ° C
Where X is the average of the two results.
There is no bias. There is no relative bias between manual and automated apparatus.
