Fact: Poor fuel quality causes generator failure. Water and the microbial growth in stored fuel can destroy engines and leave you high and dry when you need your engine most.
Critical facilities spend millions of pounds on emergency power systems and generator maintenance every year, to be assured that in the event of an emergency, their facility would
have the power they require to continue operation without interruption. But the fuel itself, the “life blood” of the whole uninterruptible power supply (UPS), is often overlooked.
Diesel begins to deteriorate as soon as it leaves the refinery although this is not a problem for most applications as the fuel is consumed within a few weeks. But, for applications
like standby generators, fuel could sit in a storage tank unused for months on end.
In just three months, without effective condition maintenance, the fuel is likely to become seriously contaminated with solid debris, water and algae. With the heavier fuels, with lower cetane levels and poorer stability characteristics, now being produced by modern refining processes, fuels are even more susceptible to biological contamination.
Although new fuel is usually fairly dry, with 60 ppm to 80 ppm to be expected upon delivery, any water is a serious threat to machinery. And, because diesel acts not only as a fuel, but
also as a coolant and lubricating agent for injection-system parts, free water can displace the fuel leaving the water to act as “liquid sandpaper” and damaging injection system parts.
Fuel injection components are engineered to incredibly fine tolerances. Any water coming into contact with the heat of the combustion chamber (up to 1000°C), immediately turns to steam and often explodes the tip of the precision injector resulting in rapid wear and even leading to a catastrophic seizure. Today’s common rail diesel engines, with injection pressures of up to 35,000 psi are intolerant of even the slightest fuel contamination.
Another serious problem for engines is the presence of microbial activity. Diesel Bug is the generic name for the microbes that grow in the fuel tank. It is sometimes referred to as algae, however, it is in fact a mixture of several different types of bacteria, mould and yeast which thrive in the water of a fuel tank, living off the hydrocarbons in the diesel.
Not only does this cause the gradual performance degradation of the fuel but it also produces a bio-mass in the fuel which will block engine fi lters. What’s more, the acid
excretion from the Bug will, over time, cause corrosion of the fuel storage tanks.
Modern fuels, which are catalytically cracked diesel fuels are particularly susceptible to deterioration, and as these fuels age, they tend to re-polymerize, forming sub-micronic, highly abrasive particulates. As the process continues, the re-polymerized molecular chain becomes longer and longer, forming agglomerates and sludge.
Another hazard facing the manager of a modern diesel engine is biodiesel. Since it’s introduction in January 2011, the new European Fuel Directive has required ultra low sulphur diesel
(ULSD) to be used in all non-road mobile machinery (NRMM). Under this new directive, high levels of sulphur have now been removed from diesel resulting in a reduction of the fuel’s lubricity.
To restore it, biodiesel with its far superior lubricity, is added. As the percentage of biofuel in the petro-diesel rises it has a “cleansing effect” on fuel tanks stripping contaminants off
the tank wall and into the fuel chain. Furthermore biodiesel is prone to react with oxygen which can set off a chain reaction within the fuel. This begins with the formation of peroxide, which promotes the formation of organic acids, which in turn, cause formations of gums and resins in the fuel, which results in blocked filters.
Biodiesel also enhances the previously discussed risks of water in fuel as it absorbs as much as four times more water from the surrounding atmosphere than normal diesel. As the fuel temperature fluctuates, this dissolved water precipitates out the fuel to form free water in the bottom of fuel tanks which, in turn, accelerates the oxidation process. It is essential to ensure fuel is kept “clean and dry” with a water content of no more than 200 ppm (0.02%).
Continual removal of water and solid contamination from the fuel is essential. This process usually comprises water separators and media fi lters. Portable fi ltration systems can be located in position near the tank. Alternatively, stand alone, automated filtration cabinets can be permanently installed directly to the diesel fuel storage tank.
Talk to an experts like us, who offer impartial advice and guidance on the cleanliness and condition of your fuel including any recommended action
Diesel begins to deteriorate as soon as it leaves the refinery
- Fuel Tank & Pipework Installation
- Fuel Polishing
- Tank Cleaning & Contaminated Fuel Recovery
- Spill Clean-up
- On Site Oil Spill Response Training & Supply of Oil Spill Kits
- Legally Required 6 Monthly Interceptor Inspections
- Legally Required Annual Fuel Tank Pressure Test & OFTEC Inspections