DIESEL FUELS & DIESEL FUEL SYSTEMS

Application and Installation GuideDiesel Fuels & Diesel Fuel SystemsAppendix 2Crude Oil FuelNote: Crude oils are not suitable foruse as fuel in all engine applications.The suitability of these fuels for useis determined on a case-by-casebasis. A complete fuel analysis isrequired.NOTICE: Use of permissible crude oilfuels can result in highermaintenance costs and in reducedengine service life.NOTICE: Caterpillar does notrecommend using any of the heavierfractions such as residuals orbottoms in engines that areconfigured to use distillate dieselfuel. Failure to follow thisrecommendation will result in severewear of components and enginefailure.Residual fuels or blended fuelswith residuals are unsuitablebecause they have a high viscosityrange, low ignition quality and highvanadium and sodium contents thatshorten engine life. Such fuels maycause high wear rates in the fuelsystem, on the piston rings, cylinderliners, and exhaust valves. Also,filter problems and deposits in thepiston ring belt may be evidenced.Special crude oil fuel pretreatmentequipment may be required and isavailable from suppliers of fueltreatment equipment. Also, it maybe essential to start and stop theengine on a better quality, ASTMNo. 2-D type fuel to preventplugging and sticking fuel systemcomponents and to permitsatisfactory starting capability.The same diesel power ratings maynot always apply for Caterpillarengines burning crude oil.Reasonable engine service life canbe achieved when proper proceduresare followed. However, the greaterrisks involved make it good practiceto include slightly higher than normalmaintenance costs when figuring theoverall economics to be gained.A fuel analysis should beperformed. Include a distillationcurve. Operation at light load is notrecommended. On occasion,operation at 50% load hasreportedly caused smoking.Engines for crude oil fuel operationshould be equipped with highertemperature thermostats, bypasscentrifugal oil filter, and fuel injectorpushrod keepers.Pretreatment of Crude Oils1. The crude may contain excessiveamounts of sediment and waterthat will require removal beforethey get to the engine. This canusually be accomplished with asettling tank, Figure 11, acentrifuge or special filteringequipment or a combination ofthese methods. The crude mayalso contain solid particles ofwax at ambient temperature thatwould plug the filters rapidly. It isimpractical to try to remove thewax, but the crude can be heatedsufficiently to dissolve it. Theamount of heat needed will varyfrom one crude to another and©2005 Caterpillar®All rights reserved. Page 49