With the recent changes in diesel fuel, the shelf life has decreased, and problems like fuel contamination and tank rusting have become more frequent. Many generally use steel tanks to store fuel, as they are durable and non-porous. They can withstand bigger impacts than heavy-duty plastic tanks and don’t absorb fuel. 

However, steel fuel storage tanks have properties that are prone to rusting due to condensation, excessive heat, and exposure to UV light. Water formation is a common issue in storage tanks due to heat gain and evaporation, and results in microbial growth and fuel-water contamination, which causes leaks, spills, and other dangerous conditions. 

Also, with corrosion, the oxidation of hydrocarbon ingredients increases, further damaging the fuel, increasing sludge buildup, obstructing release detection, clogging filters, reducing fuel lubrication, and leading to equipment and machinery failure.

Common Types of Fuel Tank Corrosion

  • Weld Metal Corrosion: Occurs due to electrolytic action when dissimilar metals interact with metal in the tank.
  • Local Corrosion: Found in areas where water accumulates or flows
  • Pitting Corrosion: Typically found at the bottom of the tanks, along the horizontal surfaces, or wherever water builds up and becomes thicker than one-third of the wall depth, which leads to external problems
  • General Corrosion: Can occur anywhere in the tank 
  • Uniform Corrosion: When water comes in contact with metal, the surface oxidises to form a uniform layer of rust. 
  • Microbial Corrosion: When oxygen is absent, microorganisms cause microbiologically influenced corrosion (MIC). Sulphate-reducing bacteria produce hydrogen sulphide, which causes sulphide stress cracking. 

Ways to Detect Corrosion in Fuel Storage Tanks

Did you know that 62% of equipment failures occur due to tank rusting, sludge buildup, or bacterial contamination? It’s crucial to implement effective measures early on to prevent accidents. You can use several methods to test for corrosive environments in the fuel storage tank.

  • Haze Test: Quick visual checks to identify bacterial growth or corrosive elements in the fuel.
  • Acid Number Test: This test determines how much potassium hydroxide base is needed to neutralise the acid in the sample. It also helps to detect both weak and strong organic and inorganic acids. 
  • Water Content Test: The Karl Fisher Titration chemical analysis method detects water formation and concentration.
  • Measuring the pH Level: The pH represents the corrosion level in the oil in its current state. Unlike the acid number test, it does not measure the concentration of the acid content. 

Expert-Recommended Suggestions to Prevent Corrosion 

Like infrastructure corrosion, which is inevitable due to climate change, small amounts of corrosion are also standard in fuel storage tanks, considering the nature of the product. However, there are ways to keep the tanks safe from the risk of moisture and corrosion. 

Use a Double-Skinned Tank

A double-skinned tank has leak detection properties and provides twice the protection against corrosion and leakage. The double skin keeps the fuel within a vacuum to prevent air or moisture from getting in. 

Apply Rust-Free Metal Paint 

There are many corrosion-resistant metal paints on the market. Use popular ones, like the Hammerite Direct to Rust Metal Paint, to repel water and prevent rust formation underneath the tank. 

Use the Nitrogen Blanketing System

Nitrogen blanketing is a practical measure to block corrosive elements in the tanks. The process begins by introducing nitrogen gas into the tank, which creates an inert atmosphere and prevents oxygen and other corrosive elements from building up inside the tank. Nitrogen blanketing also removes oxygen to avoid an explosion and creates a barrier between the fuel and air to prevent oxidation and fuel degradation. 

Implement a Routine Checkup 

Regularly scheduled checkups are essential to identify potential risks and safety hazards, whether in the gutters, plumbing system, or fuel storage trailers. Make it a point to check water levels periodically and document each inspection. If you don’t have the necessary equipment to perform a manual inspection, consult a professional. From gutter cleaning to corrosion control, professionals have the skills, equipment, and resources to perform the necessary inspections and address corrosion problems more effectively. 

Keep the Tank Full

Finally, keeping the fuel tank topped up also means leaving less space for air and water, which reduces the chances of condensation and rust formation. 

Proper fuel tank care and maintenance are necessary to prevent rust formation in new or classic models. So, without further ado, follow these suggestions to maintain your tank in top condition.