Effect of Water in Diesel Fuel

Yes it is possible that diesel is contaminated with water. There are many reasons how this can happen. Diesel fuel may contain emulsified water or free water.

Water in Fuel drops the amount of energy output/ efficiency of fuel. It can lead to soot formation and make the environment polluted. Incomplete combustion leads to emittance like CO, NOx, SOx.  

Fresh refined fuel is clear and bright, free from moisture. Visual inspection of a sample which has water in it will be hazy and not as transparent as fresh fuel. 

Free Water – large droplets which are not emulsified readily settle down. 

Free water in diesel fuel could result in – damage to injector tip, filter plugging, power loss and corrosion of engine fuel system parts rusting of tank. 

Fine rust particles generally don’t get captured in filters, these damage precision components of the Engine. 

Several factors help to raise moisture accumulation such as climate conditions, fuel handling procedures and during transportation etc.. Temperature changes can cause suspended water in the fuel to settle out. 

Water condensation in diesel fuel storage tanks is a common problem. If water is allowed to remain in the diesel while it is stored, microorganisms or bacteria can form that feed on the hydrocarbons in the fuel. This results in slime, which can clog filters.

When the tank warms, humid air above the fuel cools and water condenses from the air. Underground tanks are often cooler than the air above ground. As fuel is dispensed, warm humid air takes its place. As the air cools, water condensation forms. Areas of high humidity accompanied by low temperature would be expected to experience greater formation of water accumulation from condensation.

Warm and humid climates can create problems with microbial growth. Warmer temperatures tend to be more susceptible to microbial contamination with the subsequent water contamination of the fuel phase.

Water presence often complains about engine stalling. This can happen while the Engine is on or at rest it may refuse to start normally. Such issues happen due to problems related to combustion and compression, which are because of the water.

The best way to avoid issues in the engine because of water would be to ensure

  1. Periodic checking of Storage Tank / Day tank for water using water finding paste
  2. Check diesel receipts from the terminal for the presence of water.
  3. Carrying out Fuel Filtration and Polishing activity in the underground tank to arrest the problem at the source.