The following article is provided by CAT's Electric Power Advisor website. Click here to see original article.
"Preventive maintenance for generator sets should include a check of fuel condition. Clean fuel going into a tank does not assure clean fuel coming out. Condensation can occur in fuel tanks, whether a generator set is in regular use or sits idle for lengthy periods. Microbial growth can occur with the buildup of water. As the microbes feed on fuel and water, waste falls to the bottom of the tank. These microbial droppings are sometimes referred to as algae growth, but it bears no resemblance to real algae. It is sludge-like in nature and acidic, and can cause significant damage to engines.
This waste material can not only clog fuel filters, it can damage fuel injectors, causing downtime and expensive repairs. There is only one complete way to clean your fuel of microbial sludge – fuel polishing. Before discussing polishing, consider the drawbacks to partial steps that are not as effective. You can drain water and sludge from the bottom of the fuel tank or put biocides in the tank. Draining the tank removes most of the sludge but doesn’t remove entrained water, allowing new microbial growth. Biocides kill microbes but do not address the issue of existing sludge. And when additional fuel is added to the tank, the sludge is re-suspended.
With stricter environmental requirements, tight fuel system tolerances and pressures approaching 30-thousand psi, the smallest of contaminants or emulsified water can damage the fuel injectors and/or clog fuel filters. Fuel polishing removes the particulate matter and entrained water to greatly reduce the possibility of damage to fuel system parts. The process essentially loops diesel fuel out of and back into the fuel tank. There are three stages as the fuel is looped through the system – a centrifuge, a conditioning magnet and filters. By using this complete process to treat fuel, you eliminate the need to drain tanks.
You can make arrangements to polish fuel in one of two ways. You can add a polishing unit to your tank on site or you can include the process in preventive maintenance agreements to be performed at prescribed times. Either way, the cost is relatively inexpensive when compared to the damage the contaminated fuel can do to engines, and the cost of renting generator sets when downtime occurs.
When you consider fuel polishing, remember to use a system that includes all three stages of treatment. Some competitive offerings simply put a hose on the bottom of tanks and suck sludge from the bottom. As mentioned earlier, that is not a total solution and certainly does not remove entrained water. Remember, fuel polishing does not replace, but rather augments the filtering of fuel as it enters the tank.
Fuel polishing is an important part of your fuel quality management and will help generator sets perform up to expectations, giving you fewer worries. Please contact us for more information.
A special thanks to Dennis Albers with Carter Machinery for their participation in the development of this article."