DIESEL FUELS & DIESEL FUEL SYSTEMS

Application and Installation GuideDiesel Fuels & Diesel Fuel SystemsFuel returning to the main tankmay, because of its volume, aid withcooling, but returning to the daytank is permissible.Fuel Tank DesignConsiderationsFuel Tank SizingThe fuel tank is typically one of theleast expensive items in aninstallation, and it is wise to providetoo much, rather than too little,storage capacity. However, whilethe minimum required capacities offuel tanks can be estimated, asoutlined in the previous discussion offuel tanks, some applications mayneed to meet the requirements ofoutside organizations, such as theU.S. National Electrical Code (NEC)or National Fire ProtectionAssociation (NFPA).Fuel Tank MaterialFuel tanks made from low carbonrolled steel are best.CAUTION: Zinc, either in the form ofplating or as a major alloyingcomponent, should not be used withdiesel fuels. Zinc is unstable in thepresence of sulfur, particularly ifmoisture is present in the fuel. Thesludge formed by chemical action isextremely harmful to the engine’sinternal components.Fuel Tank InstallationLarge capacity storage tanks allowbulk purchases and minimize dirtcontamination. Maintaining full tanksreduces condensation, particularly iffuel is seldom used.Tanks may be above or belowground level, but high fuel levelgenerally should not exceed theengine injector’s height. Thisprevents possible fuel leakage intocylinders.Above ground tanks provideaccessibility, allowing for easydraining of impurities and reducingthe danger of ground watercontamination.Underground tanks allow the earthto work as an insulator, limitingradical temperature changes whichcan cause flow restrictions,condensation, and possible powerloss. Seasonal settlings are alsoavoided when burying the tankbelow frost line. In undergroundtanks, the water must be removedby pumping through a tube placeddown the fill pipe.Regulations governing theinstallation and maintenance of bothabove and below ground fuel tanksmay apply.Locate storage tank fill tubes forconvenience and safety of fillingoperations. Vents are necessary torelieve air pressure created by fillingand prevent vacuum as fuel isconsumed.Fuel Tank DrainsAll fuel tanks should have easilyaccessible drain connections. Waterand sediment that collects in thebottom of the tank must beeliminated regularly. Provide cleanoutopenings for periodical removalof sediment and trash that settlesout of fuel tanks.Well-designed tanks have largeenough clean-out openings so the©2005 Caterpillar®All rights reserved. Page 17