Whether they hold water, chemicals, or fuel, corrosion poses issues for storage tanks. Left unchecked, it can lead to the following:
- Structural Degradation
- Environmental Hazards
- Expensive Tank Failures
It can be effectively mitigated when handled correctly, so we’ll demonstrate which strategies to use to protect both interior and exterior surfaces of storage tanks throughout this article.
The Corrosion Process
Corrosion happens after metal reacts with oxygen and moisture and creates rust (iron oxide). Once this happens, the tank’s surface is compromised, leading to material degradation. However, the severity of corrosion depends on the following:
- The Tank Material
- Environmental Factors
- Exposure to Corrosive Substances
Corrosion usually does the most damage for storage tanks that are exposed to the elements, chemicals, or fluctuating temperatures – particularly common in industries like oil and gas. The tank’s lifespan ultimately diminishes if you’re not protected against this, causing anything from leaks to environmental hazards.
Key Strategies to Prevent Tank Corrosion
Fortunately, there are protective measures you can employ to minimise the likelihood of corrosion – potentially saving you a fortune in the long run:
1. Choose the Right Tank Material
Prevention starts with the material itself. Any tank that’s been with corrosion-resistant metals like stainless steel or materials such as fiberglass reinforced plastic is going to be far less prone to rusting.
However, cost and application can influence the choice of materials. Steel tanks are common but require additional corrosion protection measures to enhance durability.
2. Use a Protective Coating
Shield your tank from rust with a protective coating if you can’t get a metal with inherent corrosion resistance. We’d recommend using our cold spray solutions for this as you’ll have a low-maintenance fix that can even restore the original geometry of the metal.
Polyurethane coatings are also fine alternatives if you need something for the interior and exterior surfaces of storage tanks. Either options mentioned are solid as they form a barrier that prevents moisture and corrosive agents from ever reaching the metal beneath.
Additionally, epoxy-based and rubberized coatings offer durable solutions for specific applications, such as tanks storing aggressive chemicals. The proper application of these coatings ensures a seamless, impervious layer that prevents corrosion over time.
3. Employ Cathodic Protection Systems
For metal tanks, installing a cathodic protection system is a proven method to combat rust. This technique involves redirecting the corrosive reaction from the tank’s surface to sacrificial anodes made from materials like zinc or magnesium. These anodes corrode instead of the tank, preserving the structural integrity of the storage system.
Impressed current cathodic protection systems (ICCPs) provide an alternative for larger tanks, using an external power source to maintain protective currents and prevent corrosion on critical surfaces.
4. Optimise Maintenance for Existing Tanks
Preventative maintenance is key to extending the lifespan of existing tanks. Regular inspections identify early signs of rust, particularly on weld seams, corners, and less visible areas. Make sure you keep things like sandblasting and power washing in mind here so you can remove any rust – this lets you prepare the tank’s surface for recoating.
For older tanks, combining corrosion protection techniques like retrofitting with sacrificial anodes or applying new protective coatings can restore their durability.
5. Implement Environmental Controls
The following environmental conditions significantly impact corrosion and will accelerate the process:
- High Humidity
- Exposure to Salts
- Temperature Fluctuations
To mitigate these effects:
- Install dehumidifiers or air circulation systems to reduce interior moisture in closed storage tanks
- Use insulation to minimise condensation on the tank’s surface
- For tanks in coastal or industrial areas, select coatings with added resistance to salt and pollutants
6. Monitor and Repair Damage
Even with the best prevention strategies, tanks can develop weak points over time. Conduct regular ultrasonic or visual inspections to assess the condition of the tank material. Early intervention is how you stop something that’s ostensibly minor from escalating into significant damage.
When corrosion is detected, repair the affected area by:
- Cleaning
- Applying a Primer
- Recoating to Maintain The Tank’s Structural Integrity
Specialty Applications: Addressing Unique Challenges
Interior Surface Protection
The interior surfaces of tanks often face the harshest conditions, particularly in water tanks or those storing chemicals. Polyurethane coatings provide a durable, flexible solution for lining interiors, ensuring that the stored substance doesn’t react with the tank material.
Exterior Surface Protection
Exposure to the elements makes the exterior of a tank equally vulnerable. Applying protective coatings combined with cathodic protection systems ensures comprehensive defence against rust. For added resilience, consider UV-resistant coatings to combat sun damage.
Retrofitting Existing Tanks
For older or corroded tanks, retrofitting with our cold spray technology can breathe new life into the structure. This way, you can both prevent corrosion and restore the tank’s original geometry – it’s also far more cost-effective compared to full tank replacements.
The Role of Sacrificial Anodes
A cornerstone of cathodic protection systems, sacrificial anodes play a vital role in tank corrosion prevention. These anodes are deliberately designed to corrode, sparing the tank from the same fate. Choosing the right anode material depends on factors like tank size, contents, and environmental exposure.
Magnesium anodes are ideal for water tanks due to their high reactivity, while zinc anodes are preferred for marine or coastal applications. Regular monitoring and replacement of these anodes ensure the continued effectiveness of the protection system.
The Cost of Neglecting Corrosion Protection
You’ll face more than just financial losses if you don’t prioritise corrosion prevention – tank failure results in:
- Environmental Contamination, Particularly in Cases of Fuel or Chemical Leaks
- Operational Downtime and Reduced Productivity
- Expensive Repair or Replacement Costs
Why Prevention Matters
Whether you’re designing a new storage tank or maintaining your existing one, corrosion protection strategies are essential. The right combination of tank material, protective coatings, and cathodic protection systems will:
- Extend the Tank’s Lifespan
- Protect the Environment
- Reduce Overall Maintenance Costs
Investing in polyurethane coatings or our cold spray technology might seem like an upfront expense, but it’s nothing in comparison to how much you’ll save by preventing corrosion and minimising downtime.
Final Thoughts
Stopping a tank from rusting requires a proactive approach that considers every factor contributing to corrosion. From selecting high-quality tank materials to implementing solid cathodic protection systems, each step matters and will help you safeguard the following:
- A Water Tank
- Chemical Storage Units
- Fuel Reservoirs
Once you’ve got an understanding of the corrosion process and employ some of these proven prevention methods, your storage tanks will be able to withstand the test of time.
