18

Maintenance Section Fuel Specifications

Fuel Heaters

The fuel cloud point is related to problems with fuel filters. The heater heats the fuel above the cloud point before the fuel enters the fuel filter. This prevents wax from blocking the filter. Fuel can flow through pumps and lines at temperatures below the cloud point. The cloud point is often above the pour point of a fuel. While the fuel can flow through these lines, the wax in the fuel can still plug the fuel filter.

In some engine installations, small modifications can prevent problems that are caused by the cloud point. One of the following changes can prevent problems in many conditions: a change in the location of fuel filters and/or supply lines and the addition of insulation. In extreme temperatures, heating of the fuel may be required to prevent the filters from plugging. There are several types of fuel heaters that are available. The heaters use either engine coolant or exhaust gas as a heat source. These systems may prevent filter waxing problems without the use of de-icers. These systems may be ineffective when the fuel contains a large amount of dirt or of water. Use of a fuel heater can help eliminate some cold weather problems. A fuel heater should be installed so that the fuel is heated before flowing into the fuel filter.

Note: Only use fuel heaters that are controlled by thermostats or use fuel heaters that are self-regulated. Do not use fuel heaters in warm temperatures.

Select a fuel heater that is mechanically simple, yet adequate for the application. The fuel heater should also prevent overheating of the fuel. Disconnect the fuel heater or deactivate the fuel heater in warm weather. An unacceptable loss of fuel viscosity and engine power will occur if the fuel supply temperature is allowed to become too hot.

For additional information on fuel heaters, see your Caterpillar dealer.

De-Icers

De-icers lower the freezing point of the moisture in the fuel. De-icers are not generally needed when fuel heaters are used. If you experience trouble, consult your fuel supplier for recommendations of a compatible commercial de-icer.

i01111474

Fuel Recommendations

SMCS Code: 1250; 1280

Diesel engines have the ability to burn a wide variety of fuels. These fuels are divided into two general groups. The two groups are called the preferred fuels and the permissible fuels.

The preferred fuels provide maximum engine service life and performance. The preferred fuels are distillate fuels. These fuels are commonly called diesel fuel, furnace fuel, gas oil, or kerosene.

The permissible fuels are crude oils or blended fuels. Use of these fuels can result in higher maintenance costs and in reduced engine service life.

Diesel fuels that meet the specifications in Table 7 will help to provide maximum engine service life and performance. In North America, diesel fuel that is identified as No. 1-D or No. 2-D in “ASTM D975” generally meet the specifications. Table 7 is for diesel fuels that are distilled from crude oil. Diesel fuels from other sources could exhibit detrimental properties that are not defined or controlled by this specification.

Table 7

Caterpillar Specifications for Distillate Diesel Fuel

Specifications

Requirements

ASTM

 

 

Test

 

 

 

Aromatics

35% maximum

“D1319”

 

 

 

Ash

0.02% maximum (weight)

“D482”

 

 

 

Carbon Residue

0.35% maximum (weight)

“D524”

on 10% Bottoms

 

 

 

 

 

Cetane Number

40 minimum (DI engines)

“D613”

 

 

35 minimum (PC engines)

 

 

 

 

 

 

 

The cloud point must

-

Cloud Point

not exceed the lowest

 

expected ambient

 

 

 

 

temperature.

 

 

 

 

Copper Strip

No. 3 maximum

“D130”

Corrosion

 

 

 

 

 

 

10% at 282 ￿C (540 ￿F)

“D86”

Distillation

maximum

 

 

 

90% at 360 ￿C (680 ￿F)

 

 

 

 

maximum

 

 

 

 

Flash Point

legal limit

“D93”

 

 

 

(continued)