Diesel Fuel Quality Management
|Diesel Fuel begins to degrade after only 22 days from the time it is refined. As such, any industry that requires diesel fuels to be stored for long periods must look towards technologies or systems that can help slow down or prevent the degradation. Diesel fuel that is maintained in a condition as close to newly refined fuel will outperform a diesel fuel that is poorly maintained. The solution is to employ corrective measures that ensure fuel stability and cleanliness (AXI International).|
|Contamination is defined as the presence of unwanted foreign substances in fluid systems or fluid wetted parts. Contamination alters the properties of fluids, causes damage of fluid systems, and prevents systems and components from attaining the desired reliability and durability. Contamination is the primary cause of fluid system failures.
– Cat Commercial Diesel Engine Fluids Recommendations
|Contaminants in diesel fuel that can cause injector wear are: water droplets, particles of dust and dirt. From the terminal tank to the diesel engine tank the potential sources of contamination are (BP, U.S.):
• Dust • Water • Water & Dirt • RustFuel Quality Management Recommendations:
|A measure/treat /fuel polish strategy is the best method of protecting your diesel fuel storage tanks. Contaminants of all types can be controlled by following contamination control practices
What causes water condensation in diesel fuel tanks?
Diesel fuel tanks are subject to water condensation because unlike gasoline, diesel fuel has no vapor pressure to displace air. When a fuel tank is warm, the air expands and is forced out. As the tank cools at night, humid air is drawn back into the tank and water condenses out on the cooler tank walls. This is one reason to keep diesel fuel tanks topped off if possible. Additional water can enter a fuel system through an open fill port, a defective tank, or when rain enters a drum that has been left open. Or it can simply be transferred from another tank that is contaminated with water.
Water – A Diesel Engine’s Worst Enemy
Problems caused by water in diesel fuel systems:
- Rust – The presence of water in diesel fuel systems causes a variety of problems. Water causes steel and iron components to rust, forming loose particles of iron oxide. These rust particles can quickly clog fuel filters. Micron sized and smaller rust particles may pass though fuel filters to reach injectors, scoring surfaces and ruining fuel injection spray patterns.
- Bacteria – Standing water at the bottom of a fuel tank provides an excellent environment for a wide variety of soil bacteria to flourish. These bacteria enter through tank openings and during dispensing. Fuel and water form an interface that provides a comfortable home where bacteria can feed on diesel fuel in a moist environment. These bacteria form a slime layer that often breaks free to rapidly clog fuel filters and disperse bacteria throughout the fuel system. A fuel filter that is plugged with bacterial slime will have a dark layer of wet gel on the upstream surface. Living bacteria pump out acids as a waste product, further corroding and damaging fuel system components.
- Reduced Lubrication – Finally, any water that makes its way through to the fuel injectors reduces the lubrication properties of the diesel fuel along the way. This leads to galling, premature wear, damaged injection tips, and further corrosion of sensitive fuel system mechanical components.
- When is the best time to remove water? – When diesel fuel contaminated with water is pumped from a fuel tank, the water leaves the tank as visible floating droplets which are relatively easy to remove from the fuel using a quality fuel/water separator. If the water is not removed prior to passing through the pump, the diesel fuel/water mixture forms a stable emulsion making it very difficult to remove the water. Water dispersed this way may pass through the fuel system to be burned, but more likely, some will settle in, and corrode sensitive components.
For additional information or to schedule fuel polishing services please contact:
Power Systems Product Support