Contamination in fuel can cause fuel system components to fail, resulting in costly repairs and downtime. There are a variety of different types of contaminants that can be contained in the fuel that reaches your engine.
These contaminants are generally bundled into two broad categories: organic contaminants and inorganic contaminants.
Organic contaminants
These are generally residual components from the refining process, they form due to degradation of the fuel, cold temperatures or a reaction to additives.
These contaminants are as follows:
• Asphaltenes – From the refining process
• Paraffin wax – Which is normally present in diesel fuel and becomes more of an issue in colder climates
• Microbes (or bugs) – Present filter clogging issues and arise more commonly in bulk storage tanks
• Water – The most common form of contamination in diesel fuel, causes corrosion, loss of lubricity and potentially damaging to the injector tips
Mostly, these types of contaminants result in premature filter plugging or the development of corrosion which leads to hard particle damage.
Inorganic contaminants
Responsible for premature wear through contaminants causing abrasion and filter plugging.
These contaminants are as follows:
• Wear Metals – Which are inherent in the fuel system due to metal component degradation (sometimes caused by the corrosion aforementioned)
• Dirt – The generic term for any other types of hard particle such as sand and dust etc. that enters the fuel system from external sources
Inorganic particles can enter fuel through various sources. They can be introduced at fuel production, fuel transport vessels, storage tanks, transfer equipment, pumping stations and vehicle fuel tanks.
The increase of contamination can be accumulative through all the processes involved in moving fuel along the path from production to the engine. Each process adding more and more contamination to the originally clean fuel, rendering it unfit for use by the time it gets to the sensitive components of the fuel system.
There is no silver bullet when it comes to cleaning up dirty fuel with a single filter. If fuel is relatively clean, a quality and well selected filter can help ‘polish’ the fuel so that it meets the cleanliness specifications demanded by fuel injector equipment manufacturers. However, we don’t live in a perfect world, and even if a filter has a high efficiency, the dirtier the fuel, the more particles that pass through the filter.
Simply put, if a filter is 99.5 per cent efficient (for a given micron range), that still means 1.3 per cent of contamination in the pre-filtered fuel will get through. Let’s suppose that relatively clean fuel contains 1000 particles of a given size for every 1 millilitre of fuel. At 99.5 per cent efficient the filter would only let 5 particles through.
But let’s say the fuel is relatively dirty, with 100,000 particles of given size in the same volume of fluid, then that same filter would let 500 particles through. That’s 100 times the amount of contaminants and will accelerate wear of fuel components despite the filter still being 99.5 per cent efficient.
So, it is important to manage the filtration of fuel at the various points of distribution, handling and storage to keep the level of contamination under control.
Additional filtration may be required to do some heavy lifting when it comes to pre-cleaning fuel on a vehicle. Fleetguard Diesel Pro, Fuel Pro and Industrial Pro filters are designed for this purpose and provide excellent on-board, pre-filtering features to help greatly reduce the burden on vehicle fuel filters when dealing with dirty fuel.
The Pro Series filters have high efficiency media, large dirt holding capacity and excellent water removal capabilities over the life of the element. This will result in extending the life of the fuel system equipment and reducing filter change intervals, resulting in lower total cost of ownership of the engine. Pro Series filters are easily retrofitted to any vehicle fuel system.
It’s also important to understand how clean your fuel really is (or isn’t). Fleetguard Filtration has invested in equipment that may assist in investigating the cleanliness of fuel for aiding system improvement solutions. They have introduced an effective field test kit; FK36000, that can help quickly and easily identify if diesel fuel passes cleanliness requirements.
Managing fuel cleanliness is about understanding all of the processes that fuel travels through and identifying trouble spots for introducing additional, effective filtration to deal with practices that may not be up to scratch.
For information on fuel contamination and filters designed with Filtration Science go to fleetguard.com.