Contaminated diesel fuel can cause serious damage to your mobile equipment and infrastructure. Water, dirt, microbial growth or any other form of contamination can do a lot more than impact engine performance — they will cost you time and money.

While fixing problems after the fact is often an unfortunate part of life, the smarter move is prevention rather than cure. Simple, practical steps can ensure your fuel stays clean, dry, and fit for purpose.

Step 1: Start with Clean Fuel

A quality fuel supplier is your first line of defence:

• Request proof that the fuel meets ASTM D975 or equivalent local standards.
• Many reputable suppliers will provide fuel quality and cleanliness data.
• Initiate regular testing protocols for incoming fuel.

Step 2: Design and Maintain Tanks for Cleanliness

On-site fuel storage tanks impact the cleanliness of dispensed fuels. Design your infrastructure to maintain fuels in good condition:

• Ensure appropriate drain points: Use a tank with a built-in sump or install the tank at an orientation allowing water and debris to settle at one location for easy removal.
• Avoid drawing fuel from the tank bottom: Gravity is a good filter, and contaminants, including water, will settle to the bottom — a floating suction or elevated outlet pipe will allow cleaner fuel to be dispensed.
• Manage temperature: Tanks painted with reflective coatings or shaded minimise the impacts of thermal cycling. By reducing moisture ingression and maintaining a more constant fuel temperature, you will positively impact microbial growth, waxy solids, additive stability and fuel storage life.
• Turn over fuel often: Modern Ultra Low Sulphur Diesel (ULSD) and blended bio-diesel fuels have a shorter storage life than traditional mineral diesels. It pays to consult your fuel supplier for the recommended storage life of your fuel.
• Minimise dirt and water ingress:
  • Check seals, tank hatch covers, and breathers regularly.
  • Use deliquescent regenerative high-capacity breathers on all breather pipes.
  • Audit all infrastructure to identify points of contamination ingress

Step 3: Monitor Fuel Quality Regularly

Don’t assume clean fuel stays clean. Test your fuel and tanks periodically to:

• Check for free water, soft solids, and microbial growth
• Drain water routinely from low points
• Schedule tank cleaning as needed based on test results

Step 4: Filter Fuel in Bulk

Even fuel from a reputable supplier will carry amounts of contamination. Quality Bulk Filtration helps ensure that only clean diesel reaches your equipment:

• Clean on delivery to site: Install a single-pass filtration system at the tank inlet to remove dirt, water, and other impurities.
• Protect in storage: Use T.R.A.P.™ deliquescent breathers to block moisture and airborne particles from entering the tank vent during dispense cycles.
• Desorb moisture: For regions with high humidity issues, consider an Active Reservoir Vent (ARV) to dry fuels in storage.

Step 5: Polish Fuel at the Point of Use

The final step is also the most critical — filter fuel immediately before it is dispensed into the tank of your vehicle or machine:

• Point-of-use filters capture contaminants that may have come from the infrastructure.
• Providing your equipment with the best opportunity to perform and achieve longevity.

The Bottom Line

Clean diesel starts long before it hits your engine:

With proper design, regular monitoring, and critical location filtration, you can protect your investments, avoid costly downtime maximising productivity.