Usage:
All Caterpillar Gas Engines
- SUPPLEMENT: JUNE 1998
Engine News SEBD9256, Article 16, Page 16, January 1998; "Gas Engine Fuel Specifications".
In the "Maximum Allowable Contaminant Limits" Chart, the last line is not correct. The correct information follows:
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Gas engines are configured to operate within specific fuel ranges. Each range requires specific air fuel ratios that must be accommodated by the engine. To operate successfully an engine must be configured to operate within one of the ranges in the "Typical Heating Values" chart that follows. All Btu values are lower heating value.
Fuel Methane Number is needed to determine if a gas engine will operate successfully on a particular fuel. After obtaining a fuel analysis, determine the Methane Number by using Methane Number Program LEKQ6378. Refer to the appropriate engine performance book to determine correct compression ratio and timing for a particular Methane Number.
Allowable contaminant levels for fuel and intake air are shown in the following chart.
1. Contaminant Limits
Limits given cover contaminants that are ingested in either the fuel or intake air. For example, if chlorine is being ingested in the fuel and in the air, the total amount may not exceed 20.0 ?gCl/Btu (1hv) of fuel.
2. Sulfur Compounds
Sulfur compounds are those which contain sulfur. Total sulfur should account for all sulfur compounds and be expressed as hydrogen sulfide (H/ic/2/ice/S). See the graph titled "Changes to the H/ic/2/ice/S Limit from PNA July 1997 on G3500" that follows.
Changes to the H/ic/2/ice/S Limit from PNA July 1997 on G3500
3. Halide Compounds
Halide compounds are those which contain chlorine, fluorine, iodide, or bromine. Total halides should account for all halides and be expressed as chlorine (Cl).
4. Total Particulate Level
Total particulate level must include organic and inorganic compounds.
Water Content
Water condensation in the fuel lines or engine is not acceptable. Relative humidity of the fuel must be below 80 percent at the minimum fuel operating temperature.
Temperature Limits
Temperature limits for gas fuels are 140°F maximum and 50°F minimum. At low temperatures, hydrocarbon fuels may condense. Liquids are never permitted in the fuel. Serious damage to the engine may occur if liquids are allowed into the engine fuel or intake air systems. Liquids must be removed from the fuel by either increasing the fuel temperature to the engine regulator, or by a coalescing filter.