Keeping the wheels turning is a challenge at any time of year, but in the dead of winter it becomes even more pressing. Understanding the negative effects of cold weather will help you to ensure you get the best from your winter fuel storage.
Cold weather hazard #1: Wax buildup
When the temperature drops towards freezing, diesel fuels may react by gelling or waxing. Gelled fuel becomes part-solid, blocking fuel lines and feed pipes and causing stalls and breakdowns.
Gelling occurs when particular parts of the fuel’s complex mix of hydrocarbons drop out of solution, forming drifting crystals of wax. The process has been compared to the formation of snow, another cold-weather phenomenon — but the wax crystals look nothing like snowflakes. They’re more like pale-coloured needles drifting in the fuel mix. Because they’re long and thin, they can pass right through big pipes, but they’ll clog a filter or fuel line very effectively.
Gelling has always been a hazard in sub-zero conditions, but the problem is getting worse. That’s because the Renewable Transport Fuel Obligation (RTFO) allows fuel companies to increase the biofuel component of diesel. Biofuels are more prone than mineral oils to waxing and gelling.
There are two main ways to prevent cold-weather waxing. The first is to maintain higher temperatures. Can you keep your fuel in a heated building? That’s certainly the easiest solution, but not necessarily the most practical.
‘Plan B’ is to add a small amount of dispersant, a hydrocarbon which helps to limit the size of wax crystals. Dispersants won’t damage your engine and will keep your fuel flowing freely even if temperatures drop down to -22°C. Is there a catch? Yep! Dispersants won’t work on crystals that have already formed. You need to add these useful substances when the fuel temperature is still +2°C or higher.
Cold weather hazard #2: Water and sludge
Contaminated fuel is a problem at any time of year, but it’s particularly worrisome in winter, when low temperatures will tend to make any suspended water in the fuel condense into larger droplets. Besides the obvious impact on performance, the water droplets will become a site for microbial contamination, significantly accelerating corrosion in the tank, pipes and engine.
If you store large quantities of fuel in outdoor tanks, contamination testing should become part of your annual preparation. Take samples from the bottom, middle and top of the tank and have them analyzed for water, particulate and bacterial contamination.
If you find you’ve got a problem, hire a mobile ‘fuel polisher’ or install filtration systems of your own immediately. Removing water and heavy particulates will pay dividends year-round, not just in winter.
If you have any questions regarding winter fuel storage or would like to find out more about our storage solutions, get in touch with us on 01264 243116.