Storage Tank and Diesel Fuel Cleanliness
Keeping diesel fuel storage tanks clean and dry is the best way to ensure that you are using quality fuel and limit the probability of unplanned downtime. Ideally, we would like to remove all water from our fuel. In reality, small amounts of water will always be present. Diesel fuel will suspend very small amounts of water and pass it through with the fuel and will essentially be “invisible” to the system causing no damage. When enough water is present that it cannot all be suspended, we get free water. If free water is left unchecked, it leads to microbial growth, fuel line freeze-ups, biodegradation of fuel, and corrosion in fuel tanks that can cause filter plugging and more serious problems within the engine such as fuel injector failures.
The most common source of water developing in a fuel tank is through condensation. When the tank inside and outside temperatures are different, condensation will form in any headspace available and “sweat” into the fuel. Water forming inside the tank in this way can be difficult to control. Painting above ground tanks white and/or supplying shade can help to keep the outside and inside temperatures of the tanks more consistent. This consistency not only helps with lessening condensation, but also can help to reduce evaporation of the fuel. For equipment tanks, filling at the end of the day helps by eliminating headspace in the tanks and equalizing the temperature of the fuel. This leads to less condensation as temperatures drop overnight.
For water detection, Hydrosorb filters can help. These filters absorb small amounts of water from the fuel as it passes through. A plugged Hydrosorb filter may be an indication that a larger amount of free water is present in the tank. This helps to find a problem, but it should not replace regular inspection of the fuel in tanks to find contamination early before it causes other issues.
Advise your customers to pull a sample from the bottom of storage tanks (not through the nozzle as this is filtered) and check that it is still clear and bright. Hazy fuel is an indication that water is building up. Darker than normal colored fuel is an indication of microbial growth or fuel beginning to break down. Particulates seen can be from rust, dirt, pollen, etc. Remember, contamination can occur in equipment tanks and transfer tanks just like in larger storage tanks. When free water is found, draining or removing this free water is crucial. Installing an above ground tank on an angle to allow for easy draining is recommended.
Free water left unchecked will cause microbrial growth, biodegradation, and corrosion. Once this happens, a tank cleaning may be required to completely get rid of any potential issues. To help your customers avoid unwanted downtime, be sure to help them check their tanks ahead of the upcoming planting season.