Equipment World Digital Magazine
Issue link: http://read.dmtmag.com/i/605412
T he high pressure, com- mon rail diesel fuel injections systems used on almost all of today's Tier 4 Interim and Tier 4 Final engines require exceptionally clean fuel. Good fuel fi lters today can screen out particles as small as two or three microns, but sludge build up from microbes in the fuel can clog fi lters or lead to injector failures resulting in expensive repairs and downtime. Treatment of fuel with biocides can alleviate the problem, but for mission-critical applications such as emergency generators and key construction machines, a fuel polishing system may be in order. Dow Chemical experts say that one of the biggest obstacles to get- ting contractors to take these prob- lems seriously is that that few fl eet operators recognize the economic impact of uncontrolled microbial contamination. These effects are often subtle, and rarely identifi ed as the cause of fuel problems. ULSD and microbes According to fuel additive manufac- turer Bell Performance, the removal of sulfur from ultra low sulfur diesel makes the fuel more prone to microbial activity than it was in the past. This makes it imperative that you monitor and control microbe growth in your fuel regardless of the age of the engine. Biocides serve two functions. As shock treatments, they are designed to kill existing microbial contami- nants within a few hours. Shock treatment should achieve a greater than 99 percent kill rate within eight hours after dosing. The actual time required depends as much on mixing as it does product selection. To be effective, the biocide must be distributed uniformly through- out the contaminated system rather than just poured into the top of the vessel. The ideal treatment would be introduction of the biocide when the tank is being fi lled. In lieu of that, you may have no alternative other than to pour the treatment in the fi ll orifi ce. Prevention is best cure Keeping your fuel cool and dry goes a long way in preventing microbe buildup. Under ideal conditions, diesel fuel can be stored between six and 12 months. If the fuel can't EquipmentWorld.com | December 2015 71 maintenance | by Preston Ingalls and Richard Le Francois two treatments to ensure the highest quality fuel BIOCIDES AND FUEL POLISHING: Tier 4 Interim and Tier 4 Good fuel fi lters today can screen Compact fuel polishing systems are typically mounted on individual bulk storage fuel tanks.