By Ron Hadaway
Improvements to Tier 4 engines have helped burn cleaner fuel and reduce air emissions in articulated dump trucks, excavators and wheel loaders, to name a few types of heavy equipment. To help meet U.S. Environmental Protection Agency fuel requirement standards for all off-road diesel engines in the United States, Tier 4-compliant engines – designed with high-pressure common rail (HPCR) systems and sophisticated fuel injectors – use ultra-low-sulfur diesel (ULSD) fuel.
Fuel refineries, distributors and construction business owners are learning how to best adjust to this significant fuel chemistry change – especially in relation to how water acts in fuel – in all seasons and temperatures.
Water can be introduced into fuel as early as the refinery stage and continue to be present through the terminal, distributor and pump stages. During extremely cold weather conditions, water molecules can detach from diesel molecules, and since they are heavier than diesel molecules, they tend to settle at the bottom of diesel fuel tanks in a machine and bulk storage tanks. It can cause potential engine problems in equipment and lead to bacteria growth within the tanks.
Today’s lower sulfur amounts in diesel fuel – which removes most harmful nitrogen and oxygen compounds – multiplies saturates, which increases the tendency of fuel to gel and plug the fuel filter during cold weather conditions as well.
Heavy equipment manufacturers and dealers can help you become more knowledgeable about diesel fuel management for advanced engines. Following these eight fuel best practices can help reduce machine downtime and costly injector-plugging from water, debris and other contaminants found in diesel fuel.
Tip No. 1: Test bulk fuel tanks every six months. Fuel is one of the largest operational expenses for construction business owners. So when storing diesel fuel, the last thing you want is water or other contaminants in your storage tank. Water can degrade the fuel chemical structure and eventually lead to pump, filter and injector problems.
Every six months, you or a professional diesel fuel-cleaning and inspection service should test your supply tanks for contaminants. A small amount of water can be removed, but if significant amounts of water or sludge are found the entire tank should be drained and cleaned. To help monitor your supply tank, maintain a preventive maintenance log for the tank that includes a maintenance history, filter changes and particle counts.
Tip No. 2: Keep supply tank fuel filters clean. Often machines are filled with a 5- or 10-gal. plastic container. How do you know that the container is completely clean or how the fuel was stored before adding it to the container? To bypass these issues, make sure any fuel entering a storage tank passes through a dispensing filter which will help increase the effectiveness of the machine’s fuel filter and help prevent contaminants from entering.
Additionally, fuel tank filters should be capped and the tank vent must be filtered. Tank filters typically have a 10-micron or fewer fuel filter to help remove moisture as fuel is dispensed through the vent.
Tip No. 3: Fill machine tanks at the end of each workday. Diesel fuel can reach high temperatures during the workday. As the machine cools, condensation can form in air gaps. Make sure every machine is filled with diesel fluid at the end of the day to reduce your maintenance costs and help reduce condensation.
Tip No. 4: Use 2-micron fuel filters. Some fuel filters chosen for HPCR engines are highly effective at trapping down to 2-micron contaminants and removing free and emulsified water. No filter will remove all contaminants; however, using the cleanest fuel possible and using an efficient fuel filter helps minimize the amount of particles entering the machine.
- Drain the water trap daily.
- Never prefill a new filter during installation.
- Never open fuel connections in the system upstream of the fuel filter.
- Use the manufacturer’s recommended replacement fuel filter.
In case contaminated fuel is used in a machine, it’s best to purchase an extra fuel filter for every Tier 4 HPCR engine equipped machine and keep it on the jobsite.
Tip No. 5: Prepare for cold weather. Much of the chemistry added in the ULSD fuel can present challenges for diesel fuel suppliers to consistently provide fuel that performs well in cold climates. However, you can utilize cold-weather practices, including removing trapped water from your machine’s fuel filter daily, maintaining your machine’s battery state of charge for optimum cranking speed, installing an engine block heater and choosing the best engine oil and hydraulic/hydrostatic oil for the temperature conditions.
Maintaining a cold-weather kit and following the cold-starting procedures in your Operation and Maintenance Manual, purchasing cold-weather accessories and switching to a special winter-blend fuel – typically No. 1 and No. 2 diesel fuel – can also help you prepare for cold temperatures.
Tip No. 7: Ask a supplier to confirm the fuel’s cloud point.A fuel’s cloud point is the temperature where wax begins to drop out of fuel, creating a translucent appearance. The wax forms crystals – 50 to 200 microns in size – that can quickly plug the fuel filter. Since the cloud point from the refinery is based on the geographic location and the time of year that fuel is intended to be used, make sure to ask your supplier to confirm the fuel’s cloud point. For instance, fuel in Texas during July will have a different cloud point than fuel available in North Dakota during September.
Tip No. 8: Identify the market’s poor-quality fuel suppliers. Seeking diesel fuel that meets your needs and choosing a reputable supplier are important. You may have to pay more for clean fuel, but investing in quality fuel that is blended appropriately for the climate may give you better peace of mind, lower your consumption, provide fewer filter changes and deliver long component life. Two questions you should ask suppliers before you buy include: “What micron level of filtration is used on your delivery line?” and “Is this the best fuel available for current conditions?” A good fuel distributor will provide diesel that meets specifications for all climate environments.
Ron Hadaway is a product manager with Doosan Infracore Construction Equipment America.