With the worst of the winter weather just around the corner forklift trade association BITA is urging companies to ensure correct storage of fuel – and to check the specific fuel requirements in light of changing emissions legislation and the requirements of modern engines – particularly around the use of biodiesel and ultra low sulphur diesel.
BITA's Technical Consultant, Bob Hine explains: "Incorrect storage of fuel, potentially leading to contamination, can create real problems for forklift truck operators, particularly over winter with cold weather operation. Add into this the need to ensure that the correct grade of fuel is being used for trucks, means a winter of potential risks to operational effectiveness and efficiency."
Causes of contamination
Key causes include:
- Water in fuel
- Particle contamination/poor filtration
- Extended storage periods
- Diesel microbial contamination
- Irregular tank maintenance
Up to 7% of biodiesel can now be included in UK gas oil/red diesel and as biodiesel blends can absorb more water this can precipitate out of solution when the temperature changes. This in turn can create the conditions for microbial contamination, the 'diesel bug', leading to sludge problems. Biodiesel also oxidises and breaks down more easily in the presence of oxygen, creating peroxides that eventually form acids, leading to formation of gums and resins which can block fuel filters.
Fuel can also be contaminated with dirt, rust, sand etc which can result from simple bad fuel handling practices and cause real damage to an engine or machine and its fuel system.
- Buy from reputable sources: This will prevent the likelihood of microbe, water or particulate contaminant problems. A reputable fuel distributor turning over high volumes is more likely to be on top of preventing these problems.
- Maintain your tanks: Tanks need maintenance. There are treatments available to prevent water accumulation, but no additive can overcome a rusty tank that allows rain water in.
- Keep tanks full: This minimises development of condensation.
- Limit storage time: Ideally diesel should not be stored in excess of 12 months.
- Temperature control: Fuel should not be exposed to temperatures in excess of 35 degrees C.
- When moving fuel: Run through a filtration system.
- Regular testing for microbes and water: This will help you stay on top of stored fuel problems. Tanks should be dipped monthly to monitor water phase levels.
- Biocides should be used every 90 days to prevent the establishment of microbial contamination, especially with ultra low sulphur diesel (ULSD)
Another issue that can cause problems, both for modern diesel engines designed to meet stringent emissions legislation, and older engines designed to previous specifications, is ensuring that the correct grade of fuel is used.
Engines designed to run on 'European' grade diesel, with a cetane rating of 51 (the cetane number being the measure of how readily diesel burns under compression) can struggle to run effectively on UK red diesel, which has a cetane level of 45.
The advent of ULSD can also mean a reduction in the 'oiliness' of fuel, or lower 'lubricity'. This can potentially be an issue if used in older engines which were not designed to run on ULSD.
For some engines, fuel containing the maximum 7% of biodiesel can result in reduced cold-weather handling performance and more water pick-up potential, meaning a great possibility of corrosion in filters. This has led to some suppliers offering so-called 'FAME-free fuel' which claims to contain no biodiesel, but this is extremely difficult for a supplier to guarantee, given the prevalence of biodiesel in the supply chain, so relying on this has potential problems.
Alongside the use of the correct fuel and fuel storage protocols, general vehicle maintenance tips allied to fuel and efficient operation include observing the manufacturer's fuel filter service life recommendations, particularly around frequency of replacement, the daily draining of water from fuel filters, and replacing a vehicle's fuel filler cap immediately after refuelling.
Hine concludes: "To keep your fleet operating at maximum efficiency, with minimum downtime, effective fuel storage and tank maintenance is vital. If this is matched with a meticulous adherence to the fuel grade needs of your fleet, be it brand new or of a less recent vintage, it will help ensure that the winter weather won't stop your business in its tracks."