Surface Tolerant Epoxy Solutions: Belzona 5831 (ST Barrier) vs Belzona 5831LT 

What is Belzona 5831 (ST Barrier)?

Belzona 5831 (ST barrier) is a two-part surface tolerant epoxy coating specifically formulated for application on wet and oil-contaminated surfaces, as well as for underwater applications. The coating displaces water from the surface ensuring maximum adhesion to wet substrates. This makes it the ideal solution for corrosion and deterioration in various critical areas such as equipment in splash zones, sweating pipework, joints and flanges, tanks and bunds, and submersible equipment

Once cured, it forms a robust barrier coating, offering equipment long-term protection against corrosion and deterioration. This product is the ideal choice for substrate temperatures in the range of 77 °F to 104 °F (25 – 40 °C). 

What is Different About Belzona 5831LT?

Specifically engineered for substrate temperatures ranging from 41 °F to 86 °F (5 – 30 °C), this surface tolerant epoxy coating stands as a tailored solution for lower temperatures or colder waters. However, this variant still inherits all the benefits of Belzona 5831 (ST Barrier), including moisture tolerance and the ability to displace surface contaminants. Both formulations provide long-term protection against corrosion, erosion, and environmental attack for metallic and non-metallic surfaces. A precise selection between the two products can, therefore, be made based on the thermal demands of the application.  

Benefits of Belzona 5831 Products:

  • Cures underwater and bonds to wet surfaces 
  • Tolerant to oil contamination 
  • No shrinkage, expansion or distortion 
  • Prevents galvanic corrosion  
  • No hot work 
  • Solvent-free, reducing health and safety risks 
  • Excellent bonding to many metal surfaces including steel, stainless steel and other specialist steels as well as to non-metallic surfaces such as concrete and brick 

Case Study: Belzona 5831 (ST-Barrier) Rescues Offshore Risers

Off the coast of Croatia, an offshore gas production platform faced severe corrosion issues with its risers. The problem was exacerbated by a previous coating failure which had left the substrate exposed. The Client needed a solution that could repair the existing corrosion damage and ensure long-term protection for the future. 

Why Did the Client Choose Belzona 5831 (ST-Barrier)? 

The Client chose Belzona 5831 (ST-Barrier) for its dual benefits of long term corrosion protection and excellent adhesion to wet and minimally prepared surfaces. Notably, these unique capabilities are well-suited to this challenging marine environment. Plus, the straightforward in-situ application process presented a practical, convenient solution. 

The standard temperature version of the coating was chosen as this application took place in the Adriatic Sea in sunny July, so the favourable weather conditions negated the need for the lower temperature version of the product. 

The surface of the riser was severely corroded

How Was the Solution Applied?

First, to prepare the surface it was grit blasted to remove the existing coating and the corrosion to achieve a surface cleanliness of Sa2½ with a minimum profile of 75 microns. The first coat was then applied using a short, bristled brush and a roller, scrubbing the product well into the surface to ensure complete wetting. The next day, a second coat was also brush-applied, completing the two-coat system with simple tools. With the in-situ application, a quick curing time and no need for hot work, the application process was safe and streamlined. 

What Was the Result?

The completed application is now safeguarding the integrity of these crucial components. The application of Belzona 5831 (ST-Barrier) not only successfully repaired and protected the riser from corrosion, but also exemplified this surface tolerant epoxy’s efficacy in safeguarding critical offshore infrastructure.  

Case Study: Belzona 5831LT Keeps the Power Flowing

At a New Jersey power peaking plant, Corrosion Under Insulation (CUI) posed a significant threat. Four fuel oil heater cylinders, crucial for the power generation process, were severely corroded due to years of service in cold weather. This corrosion increased the risk of oil leaks, which would create environmental contamination. Furthermore, a breakdown of one of the cylinders would necessitate an unplanned shutdown, resulting in millions of dollars of estimated daily losses

The cylinders were suffering from severe corrosion under insulation

The cylinders were suffering from severe corrosion under insulation

What is the Role of the Cylinders? 

The heating cylinders are integral to the power generation process. They house oil heating elements to warm fuel during cold weather, facilitating the smooth flow of oil to boilers. This produces heat, generating steam that drives the turbine for electricity. Their vital role in delivering a dependable supply of extra electrical power during demand spikes, it was imperative to repair and protect them before the worst of the coming winter. 

Belzona 5831LT: Tailored for Cold Weather 

The Client opted for Belzona 5831LT as this surface tolerant epoxy was specially tailored for lower temperatures, making it an ideal choice for the outdoor, in-situ application required during the cold New Jersey winter. The metal was so corroded that grit blasting was impractical, due to the risk of further damaging the metal substrate. Therefore, Belzona 5831LT‘s tolerance for surface contamination as well as its excellent long-term corrosion resistance made it the optimal solution.  

How Was the Solution Applied?

Due to how advanced the CUI had become, the surface was meticulously prepared using a power tool to achieve SSPC-SP11 bare metal conditions. A short, bristled brush was then used to apply the product, forcing into the surface to ensure maximum adhesion. The next day, a second coat was applied in the same manner, completing the system and ensuring long-term corrosion protection.  

A cost-effective solution using surface tolerant epoxy coating Belzona 5831LT

A cost-effective solution using surface tolerant epoxy coating Belzona 5831LT

What Was the Result:

The three-day repair, proved to be a highly cost-effective solution. Belzona 5831LT not only addressed the corrosion challenges but also ensured long-term protection, extending the equipment service life. This proactive approach using Belzona’s surface tolerant epoxy coating safeguarded the plant from unexpected shutdowns, saving them millions of dollars, minimising financial impact and averting environmental risks from potential oil leaks. As a result, the power peaking plant is now well-prepared for winter operations, ensuring the reliability and longevity of its essential components.  

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