When storing diesel fuel, most everyone is familiar with the adverse effects of water or growth in their bulk tank. Are there other factors or elements that cause diesel fuel to degrade?
The simple answer is YES.
Storage life of any fuel is dependent on the storage conditions. Untreated diesel fuel can be expected to stay in a usable condition for approximately 12 months, when stored at an ambient temperature of 68°F; and 6-8 months when stored at temperatures exceeding 85°F.
As diesel fuel gets older fine sediment and gum forms in the diesel, brought about by the reaction of diesel components with oxygen from the air. Oxidation eventually leads to fuel darkening and stratifying (layers in fuel/separation). Sediment and gum will block fuel filters and burn inefficiently in the engine, often leading to carbon and soot deposits on injectors and other combustion surfaces. Let’s discuss conditions that accelerate the aging process, additives to counteract this process and suggestions for extending storage life.
5 THINGS TO HELP EXTEND STORAGE LIFE
Contact with Metals
Verify that the fuel is not in contact with any surfaces containing zinc, copper or compounds that contain these metals (e.g. brass). A metal deactivator may help if this is the case.
To remove any chance for fungus growth, create a regular maintenance program to remove water and dirt from fuel tanks. Condensation is the most common way for water to get into a fuel tank. The rate at which water collects via condensation varies depending on local climate and is higher in hot, humid areas.
Keeping a tank full is the easiest way to limit water in the tank as this reduces the space for water to condense. Tanks should have a well-defined low point, such as cone down bottoms, where water collects and can be drained. Water should be drained weekly in bulk fuel tanks. If the tank shows no tendency to collect water the frequency can be extended but should be done at least monthly.
Tanks should be emptied and cleaned at least once every 10 years, or more frequently if you have a major contamination. Establish a system for filtering the contents of the main storage tank through a recirculating filter system (filters should be checked and changed at regular intervals). Make this automatic and reduce problems by removing sediment and gums.
Replenish Fuel Stock
it is best to do this in the winter season November – March. This will ensure the fuel will not cause wax problems no matter what season it is used. Verify the winter fuel matches the cloud point for your area to avoid gelling caused by wax drop out in cold weather.
Use and Replace Fuel
If possible, plan to use the fuel within one to three years and replace it with fresh fuel.