0323607 JOHNSON FITTING, Lube

Table 1
Cat NGEO SAE 40 Viscosity Grade Properties
Characteristic ASTM Test Ultra 40 Advanced 40 Cat EL350 Cat NGEO
Flash Point 0 ° C (32 ° F) "D0092" 247 252 247 252
Pour Point 0 ° C (32 ° F) "D0097" −21 −30 −21 —15
Viscosity (cSt) at 100 °C (212 °F) "D0445" 13 13 13.5 13.2
Viscosity Index "D2270" 95 min 103 97 98
Weight (Percent) of Sulfated Ash "D0874" 0.54 0.5 0.54 0.52
Total Base Number "D2896" 6 6 6.2 5.6 Engine Oil and Sour Gas Fuels
Many gaseous fuels contain sulfur compounds. These compounds are primarily composed of hydrogen sulfide (H2S). Gaseous fuels with less than 0.43 mg H2S/MJ (.45 µg H2S/Btu) are considered to be sweet gas.Gaseous fuels with more than 0.43 mg H2S/MJ (.45 µg H2S/Btu) are considered to be sour gas. Sour gas can reduce the service life of an engine and of the engine oil. When the sulfur compounds are combined with water, acids are produced in the engine oil. These acids attack the metals in the engine crankcase and in other components. This causes corrosive wear. To reduce the effects of these sulfur compounds, Caterpillar recommends the use of devices that treat the fuel. For further information, see this Special Publication, "Hydrogen Sulfide Effects on Engine Maintenance Costs" in the Fuel Specifications section.Note: Caterpillar does NOT recommend the use of engine oils with a high concentration of sulfated ash (greater than 0.6 percent) in order to reduce the harmful effects of sour gas. High levels of sulfated ash (greater than 0.6 percent) may produce excessive deposits on the valves and on the turbine wheel of the turbocharger. These deposits will reduce the service life of the engine. These deposits will also increase the cost of maintenance.Engine Oil and Bio-Gas Fuels
Bio-gas fuels that are generated from landfill or digester gas power plants can include contaminants that react with the engine lube oil. This can create varied combustion deposits. Excessive deposits on the piston, the liner, and the cylinder head can occur if the oil is not properly matched for the application. Laquering of the liner may also occur.Lube oils that are specifically designed for applications that use bio-gas are recommended. These oils should have a concentration of sulfated ash that is not greater than 0.6 percent. When possible, these oils should also be formulated with Group II base stock. Group II base stocks have been shown to provide reduced engine deposit buildup. The use of a lube oil with a high concentration of sulfated ash will result in excessive deposits in the combustion chamber. Because of the inconsistent, variable composition of most bio-gas fuels, the lube oil may react differently to the composition of a particular fuel. Use the S O S oil analysis program to determine the proper oil change interval.For new installations, sample the oil frequently in order to establish a consistent program for oil changes. Initially, sample the oil on a daily basis. The properties of landfill gas can change rapidly. Therefore, it is necessary to continue to monitor the oil on a weekly basis or two times per month in order to ensure adequate protection.Consult your local Caterpillar dealer for a recommendation for lube oil for your bio-gas application.S O S Services Oil Analysis
Caterpillar recommends the S O S oil analysis program in order to monitor the condition of the oil. The analysis can help determine the maintenance requirements for the engine. The S O S program is part of the preventive maintenance program. For further information about the S O S program, see this Special Publication, "S O S Services Oil Analysis" topic.