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Filtering of the Fuel
The quality of the fuel is an important consideration for maintenance of the fuel filters. A poor quality of fuel can reduce the service life of the fuel filter elements by 50 percent or more. To increase the service life of fuel filter elements, use a good quality of fuel. Monitor the readings of the fuel gauges and service the fuel filters at the recommended intervals.The secondary fuel filters that are supplied by Cat are mounted remotely from the engine. The filters are installed in the fuel supply line directly before the engine.
For heavy fuel oil with a viscosity of 40 cSt at 50 °C (122 °F), the viscosity of the fuel must be reduced prior to the fuel filters. This will allow fuel to pass through the filter elements without causing the elements to collapse. Reduce the viscosity to a range that is between 15 and 20 cSt at 50 °C (122 °F).
Overheating the fuel or the fuel filter can result in personal injury and/or damage to the engine. Use extreme care and caution for heating of the fuel filter.
Heating of the fuel filter will enable the viscosity to be reduced. The fuel temperature and warm-up time depend on the type of fuel and installation.
The viscosity of the fuel at the engine must be between 10 cSt and 20cSt. The temperature of the fuel at the engine must not exceed 135 °C (275 °F).
Heating of the Fuel
Precise temperature control of heavy fuel oil is critical for the most complete combustion, centrifugal cleaning, and settling of contaminants. If the temperature is not properly controlled, sludge and vapors can form. This material inhibits the treatment of the fuel. Also, combustion of the fuel is reduced. The result is a reduction of the service life of the fuel system components and the engine.Note: The temperatures that are required for controlling sludge and vapor mainly depend on the fuel quality. An analysis of the fuel is necessary to determine the proper temperature for both treatment and viscosity.The following parameters can be used as initial indications of improper temperature control:
Variation of the exhaust port temperatures
Viscosity of the fuel
Knocking
Fuel temperature
Opacity of the exhaust smokeUse the jacket water heaters before starting an engine with heavy fuel oil. Use of the jacket water heaters will reduce the viscosity of the fuel in the fuel injectors. Startability will be improved.Table 5 lists the jacket water temperatures that are appropriate for different fuel viscosities.
Table 5
Fuel Viscosity and Jacket Water Temperature
Fuel Viscosity Jacket Water Temperature
Less than 40 cSt at 50 °C (122 °F) 45 °C (113 °F)
More than 40 cSt at 50 °C (122 °F) 65 °C (149 °F) Normally, deactivate the jacket water heaters after the engine has started.Analysis of Heavy Fuel Oil
Caterpillar Inc. does not provide analyses of heavy fuel oil. Chemical labs throughout the world can evaluate fuel properties on a regular basis. Analyses of heavy fuel oil may also be obtained from these organizations: independent testing laboratories, oil companies