Nicco Blog – NICCO ENGINEERING SERVICES LIMITED

Restoring an Aged Concrete Wall in a Power Plant with Belzona 4111

admin — Tue, 05 May 2026 08:34:45 +0000

The Challenge

A power plant was facing a serious concrete deterioration issue on an external wall structure that had been in service for nearly 25 years. Over time, continuous exposure to the plant environment, elevated operating temperature, weathering, moisture ingress, and natural aging had caused significant degradation of the concrete surface.

During inspection, the wall showed visible signs of distress, including surface cracking, spalling, exposed and damaged concrete sections, staining, and large areas of uneven, weakened substrate. In some areas, the deterioration had progressed deeply, creating an irregular surface profile and raising concern over further damage if left untreated.

The operating temperature in the area was approximately 120°C, making it essential to select a repair material capable of withstanding the service conditions while restoring the damaged concrete profile.

Conventional Repair Concern

A conventional civil repair would have required extensive surface removal, rebuilding, curing time, and possible disruption to nearby plant operations. The client required a practical, in-situ repair method that could restore the damaged concrete area without a lengthy outage or complex reconstruction work.

Why Belzona?

Belzona offered a cold-applied repair alternative that could be carried out directly on site. The solution allowed the damaged concrete surface to be rebuilt and profiled without hot work, helping the plant avoid unnecessary operational disruption while improving the condition of the aged wall.

Belzona 4111 was selected for the repair due to its suitability for rebuilding and resurfacing damaged concrete surfaces. The material provided a strong repair system for restoring the uneven and deteriorated wall section and creating a smoother, more protected surface.

The Belzona Solution

The damaged concrete wall was first inspected to identify loose, cracked, and weakened areas. All loose concrete, contaminants, dust, and friable material were removed from the repair zone to achieve a sound substrate for application.

After surface preparation, Belzona 4111 was mixed and applied to the damaged areas of the concrete wall. The material was used to rebuild the lost profile, fill irregular sections, and restore the surface geometry. Special attention was given to the severely degraded zones, cracks, edges, and uneven areas to ensure proper coverage and continuity of the repair.

The application was carried out in situ around the plant structure and nearby pipe supports. The Belzona material was carefully spread and finished to provide a uniform repaired surface over the affected concrete section.

Products Used

Belzona 4111 – Used for rebuilding, resurfacing, and repairing the deteriorated concrete wall.

Application Area

The repair was performed on a concrete wall structure in a power plant that had been in service for approximately 25 years.

Operating Conditions

The repaired area was exposed to an operating temperature of approximately 120°C.

The Outcome

The Belzona repair restored the damaged concrete wall surface and improved the condition of the deteriorated area without the need for major civil reconstruction. The before photographs showed heavy surface degradation, cracking, staining, and loss of concrete profile. After application, the affected areas were rebuilt with a smoother and more uniform finish using Belzona 4111.

The repair helped the plant address the aging-related concrete damage in a practical and cost-effective manner while avoiding the delays typically associated with conventional repair methods.

Key Benefits

✅ In-situ repair – Work was completed directly at site without major dismantling or reconstruction.
✅ Cold-applied solution – No hot work was required during the repair process.
✅ Profile restoration – Damaged and uneven concrete areas were rebuilt with Belzona 4111.
✅ Reduced downtime – The repair approach helped avoid a lengthy conventional civil repair process.
✅ Improved surface condition – The deteriorated wall section was restored to a smoother, more protected finish.

Conclusion

This application demonstrates how Belzona 4111 can be used as an effective solution for restoring aged and damaged concrete structures in demanding industrial environments. For this power plant, the repair provided a practical way to address deterioration on a 25-year-old concrete wall exposed to high operating temperature, helping extend the serviceability of the structure and reduce the need for extensive civil replacement work.

Belzona Seals Persistent Cooling Tower Leak at Outlet Pipe Interface

admin — Mon, 16 Mar 2026 07:38:11 +0000

A cooling tower at a leading industrial gas producing facility in India had developed a profuse leakage at the peripheral junction of the concrete wall and the outlet pipe section. The ongoing leakage created a maintenance concern for the plant and required a practical sealing solution that could be applied effectively on site.

The application was carried out in 2025 for an industrial gas producing facility asset with a concrete & metal substrate.

The Challenge

Leakage had been observed on the cooling tower wall throughout the periphery of the outlet pipe section, indicating a failure at the interface between the pipe and the surrounding concrete. Left unresolved, this type of leak can continue to undermine asset condition and leads to plant shutdown. Plant engineers needed a reliable, long-term repair approach that would address the leak without resorting to more disruptive remedial work followed by wrapping of the metal pipeline which was thinned out as well.

The Belzona Solution

Working closely with plant engineers, our Belzona sales engineer recommended a repair strategy using Belzona 4211 in combination with Belzona 4111 (Magma Quartz) for leakage arresting & Belzona 1161- Super UW Metal in conjunction with Belzona –9341 Reinforcement Tape for pipe surface restoration. The system was selected to seal the gap between the pipe and the concrete and create a durable protective layer over the repaired area.

Application Method

The repair was completed in accordance with Belzona Know-How System Leaflets TCC-9. Surface preparation began with chipping off the loose mortor of the concrete followed by manual abrading to ensure the area was properly prepared for application. The cracks and gap between the pipe and concrete were then sealed using Belzona 4211. Once this had been forced into the void, Belzona 4111 was applied over the treated area to complete the repair and provide a robust sealed finish.

Visual Repair Progress

The project photographs show the progression of the repair from visible leakage on the cooling tower wall near the outlet pipe section, through the insertion of Belzona 4211 into the gap, to the final over-application of Belzona 4111 across the repaired area. The completed repair presents a sealed and uniform finish around the pipe interface.

Result

By combining effective surface preparation with a proven Belzona sealing system, the plant was able to address a long-term leak at a critical cooling tower location. The repair delivered a practical in-situ solution and demonstrated how Belzona materials can be used to restore integrity and improve reliability in concrete cooling tower structures.

DM Water Drainage Line Reclamation Using Belzona Solutions

admin — Mon, 17 Nov 2025 10:00:35 +0000

The DM (Demineralized) Water Drainage Pipeline in a critical utility section had suffered extensive corrosion damage due to prolonged exposure to water and environmental factors. Upon inspection, NESL’s service engineers identified severe metal loss and pitting corrosion on both the inner and outer surfaces of the carbon steel line.

Challenge

Replacing the damaged section of the drainage line would have required shutdown of the water treatment unit, extensive cutting, welding, and hydro-testing—making it a costly and time-consuming process. The client therefore sought a cold-applied repair solution that could:

Be executed in situ while the plant remained in operation.
Provide long-term corrosion protection against continuous exposure to DM water.
Eliminate the need for hot work and replacement.

Proposed Solution

NESL recommended a Belzona polymeric repair and protection system comprising:

Belzona 1161 (Super UW-Metal) – for rebuilding and profiling the heavily pitted surface.
Belzona 1321 (Ceramic S-Metal) – as a corrosion-resistant topcoat providing a smooth, hydrophobic finish.
Belzona 9341 Reinforcement Sheet – used to strengthen the repair in high-stress or structural areas.

Application Procedure

All work was carried out by NESL’s certified Belzona applicators under live plant conditions.

Surface Preparation

The pipeline surface was mechanically cleaned using power tools and abrasive blasting (where accessible) to achieve a minimum SA 2.5 surface cleanliness and a surface roughness of 75–125 microns.
All corrosion products and loose scales were removed, and the area was thoroughly degreased using Belzona 9111 (Cleaner/Degreaser).

Rebuilding of Metal Loss

Deep pitting and wall thinning were rebuilt using Belzona 1161.
The material was mixed in the prescribed ratio and applied using a steel spatula to rebuild the original profile of the pipeline.
In areas where the pitting exceeded 3 mm depth, Belzona 9341 reinforcement sheet was embedded into the first layer to provide additional mechanical strength.

Surface Smoothing and Coating

After initial curing, the surface was lightly abraded to achieve a smooth transition.
A full overcoat of Belzona 1321 (Ceramic S-Metal) was then applied in two coats, with contrasting colors to ensure uniform coverage and desired DFT (Dry Film Thickness).
This coating provided an impermeable, corrosion-resistant barrier against DM water and environmental moisture.

Quality Checks and Curing

Coating thickness was verified using a DFT gauge, ensuring consistent coverage (minimum 500 µm total).
After full cure, a spark test was conducted to confirm coating integrity.
The system was then allowed to cure before exposure to service conditions.

Results

The Belzona-applied section was reinstated within 24 hours, avoiding any production loss.
The pipeline integrity was fully restored without any hot work or welding.
The client achieved significant cost savings—over 70% compared to replacement—and gained a durable corrosion protection system expected to last over 5 years in continuous service.

Conclusion

The use of Belzona 1161 & 1321 with 9341 reinforcement provided a cold, safe, and efficient repair method for the DM water drainage line.

This case highlights how NESL’s expertise in polymeric repair technology enables industrial plants to restore critical assets without costly shutdowns, ensuring operational continuity, safety, and sustainability.

In-Situ Repair of Worn Coal Mill Shaft Using Belzona 1111

admin — Wed, 28 May 2025 06:50:46 +0000

The Challenge

A leading thermal power plant in India experienced severe wear at the bearing area of a coal mill shaft. Upon initial inspection, our service engineer observed:

Significant material loss and surface degradation around the bearing zone

Irregular shaft diameter causing potential misalignment with bearings

Signs of accelerated wear likely due to abrasive conditions and operational stress

Risk of imminent failure if left unaddressed, which would lead to extended downtime

This wear was causing operational inefficiencies and posed a risk of unexpected shaft failure, demanding urgent intervention.

Conventional Solution

The traditional repair involved welding metal buildup followed by machining to restore shaft dimensions. This method would require at least 72 hours of downtime and Involves heat input, risking shaft distortion and misalignment. Considering the time and cost constraint involved in replacement of the shaft, client choose to go with cold repair method.

The Belzona Solution

Our service engineer recommended Belzona 1111 (Super Metal). Belzona 1111 is a 2-part epoxy-based repair composite designed for metal repair and protection. It Cures rapidly, minimizing downtime and provides strong adhesion and excellent wear resistance suitable for heavy industrial use.

Application Process

The repair was carried out adhering strictly to Belzona System Leaflets:

Thorough degreasing and cleaning of the shaft surface

Abrasive blasting to near-white metal cleanliness (SA 2.5), ensuring optimal surface profile for adhesion

Verification of surface roughness and cleanliness per Belzona standards

On-site mixing and application of Belzona 1111 by our trained technicians

Entire process completed within 12 hours, allowing fast return to service

The Outcome

60 hours of downtime saved compared to traditional welding and machining

No heat input, so no risk of shaft distortion or misalignment

Shaft restored to precise dimensions with improved wear resistance

Avoided costly shaft replacement and extended operational disruptions

Thermal power plant resumed production promptly with confidence in the repair’s reliability

Restoring ACW Pump Rubber Joint with Belzona Composite Repair System

admin — Thu, 17 Apr 2025 05:35:50 +0000

The Challenge

A major power plant in India encountered a critical maintenance challenge with one of its ACW pipeline components. The rubber expansion joint at the discharge side of the ACW pump had deteriorated severely. Constant exposure to extreme heat and environmental conditions had caused the rubber joint to crack, tear, and degrade significantly. The joint had developed multiple leak points, posing a threat to the operational safety and efficiency of the cooling system.

Conventional Solution:
The traditional approach would be to replace the rubber joint entirely — a process that is time-consuming, costly, and would require extended shutdowns, negatively impacting plant productivity.

Why Belzona?

Considering the downtime and cost constraints involved in replacing the rubber joint, the client turned to a reliable alternative — Belzona’s cold-applied composite repair system. This offered a non-intrusive, fast, and long-lasting solution to restore the joint’s structural integrity without replacement.

The Belzona Solution

Surface Preparation:
The rubber joint was first cleaned thoroughly to remove dust, debris, and loose rubber fragments to ensure proper adhesion of Belzona products.

Products Used:

Belzona 2911 – Applied as a conditioner to promote adhesion on the rubber substrate
Belzona 9341 – Reinforcement tape used to strengthen the repair
Belzona 2211 (MP Hi-Build Elastomer) – A flexible, high-performance elastomer used to rebuild and seal the damaged rubber surface

Application Process:
The system was applied in accordance with the guidelines from the Belzona System Leaflet. The repair was carried out on-site with minimal equipment and no hot work, ensuring the safety of personnel and avoiding unnecessary operational disruptions.

The Outcome

✅ Rapid Turnaround – Repair was completed in a fraction of the time needed for part replacement
✅ Cost-Effective – No need to source and install a new rubber joint
✅ Durable & Flexible – The restored joint can now withstand thermal stress and vibration
✅ Extended Service Life – Increased the lifespan of the equipment with a proven, reliable Belzona solution

Thanks to the quick response and robust performance of Belzona’s elastomeric repair system, the power plant was able to avoid equipment replacement, minimize downtime, and ensure the long-term reliability of its cooling system. This case stands as a strong example of how Belzona empowers industries with innovative and efficient cold repair solutions.

NESL Restores Ship’s Conduit Pipe and Junction Box with Belzona 1311 & Belzona 5811

admin — Mon, 07 Apr 2025 07:59:28 +0000

At NESL, we pride ourselves on delivering cutting-edge solutions to complex marine Enviornmental challenges. Recently, our team undertook a critical project to restore a severely corroded conduit pipe and junction box on a ship without any hot work at the location, showcasing our expertise in fabrication, repair, and advanced coating technologies. This case study highlights the step-by-step process we followed to bring this vital infrastructure back to peak performance, ensuring durability and reliability for our client.

The Challenge: Severe Corrosion Threatening Operational Integrity

During the initial inspection, our team identified profound corrosion in the ship’s junction boxes and conduit pipes. The condition of the junction boxes was compromised, with deeply corroded components posing a risk to the vessel’s electrical systems. The conduit pipe, a critical element for protecting wiring, had also suffered extensive damage. Left unaddressed, these issues could have led to operational downtime, safety hazards, and costly replacements.

Assessment and Preparation

The restoration began with a thorough assessment of the damage. After an initial cleaning of the deeply corroded conduit pipe, our technicians used power tooling to remove rust and debris, preparing the surface for repair. This meticulous preparation ensured a strong foundation for the subsequent steps.

Fabrication of New Components

To address the corrosion, NESL’s skilled engineers fabricated new flanges and covers from scratch. This process, carried out with precision in our state-of-the-art facilities, ensured that the replacement parts met the exact specifications required for the ship’s junction box system. The newly fabricated flanges were cold bonded to the junction boxes using Belzona 1311, a high-performance epoxy-based composite known for its exceptional adhesion and durability.

Repairing Profound Damages

The corroded flange and cover were removed, and repairs commenced immediately. Using Belzona 1311, our team expertly repaired profound damages to the conduit pipe and junction box. This advanced material not only restored structural integrity but also provided long-term resistance to future corrosion.

Protective Coating Application

To safeguard the restored components, we coated the flanges with Belzona 5811, an industrial-grade protective coating designed to withstand harsh marine environments. The final wrapping and coating were completed using Belzona 5811 in conjunction with reinforcement tape, ensuring a robust barrier against moisture, salt, and other corrosive elements.

Final Inspection and Results

The project concluded with an aerial view of the restoration, showcasing the seamless integration of the repaired and newly fabricated components. The conduit pipe and junction box were fully restored, exceeding industry standards for reliability and longevity. Our client was thrilled with the outcome, confident in the enhanced performance and extended lifespan of their ship’s infrastructure.

Why NESL?

This project exemplifies NESL’s commitment to excellence. By combining advanced materials like Belzona 1311 and 5811 with our expertise in fabrication and repair, we delivered a solution that not only addressed immediate concerns but also provided lasting value. Our ability to tackle complex challenges with innovative techniques sets us apart as a trusted partner in industrial restoration.

Thank You for Your Trust

We extend our gratitude to our valued client for entrusting us with this critical project. At NESL, we’re dedicated to pushing the boundaries of what’s possible, ensuring that every job—big or small—is completed with precision, care, and a focus on customer satisfaction.

Restoring Wind Girder Integrity at a Leading Chemical Plant in India with Belzona Coatings

admin — Wed, 19 Mar 2025 07:57:22 +0000

In the construction of storage tanks, wind girders (or stiffening rings) play a critical role. They prevent the tank walls from buckling under wind loads, especially when the tank is empty, ensuring structural stability and safety. However, when these girders are compromised by corrosion, the entire tank structure becomes vulnerable.

The Challenge:

A renowned chemical plant in India encountered this exact issue. Their storage tank’s wind girder had suffered severe corrosion, with rust, pitting, and metal flaking visibly compromising the girder’s integrity. If left unaddressed, the structure faced potential failure under environmental stress.

Our Solution:

Upon inspection by our experienced service engineers, we identified the extent of the damage and offered a turnkey solution with our skilled application team, ensuring not just product supply, but a comprehensive service.

Surface Preparation:
The team meticulously prepared the wind girder surface using non-abrasive hand tools, removing rust and ensuring a smooth, clean base without compromising the substrate.

Application of Belzona 1111:
We used Belzona 1111 (Super Metal), our high-performance composite repair material, to rebuild and restore the girder’s surface. Its superior adhesion and resistance to corrosion made it ideal for this application.

The Outcome:

The wind girder was fully restored to its original profile and strength.
The plant benefited from minimal downtime and a cost-effective, long-term solution without the need for structural replacement.
The client praised the seamless coordination, technical expertise, and quality of Belzona products.

If your facility faces similar challenges, reach out for a free consultation. Let us help you safeguard your assets.

Extending the Life of a Corroded & Cavitated End Suction Pump with Belzona Solutions

admin — Mon, 06 Jan 2025 07:04:54 +0000

The Problem

A critical end suction pump used in a continuous service application suffered severe corrosion throughout its inner casing. Over time, the harsh operating environment led to pitting and rusting of the metal surfaces, significantly compromising the pump’s performance and efficiency. The client faced a pressing challenge: the need for a quick, cost-efficient repair solution that would not only restore the pump’s integrity but also extend its operational life. Adding to the urgency, the client required the repair to be executed within a minimal outage window to ensure the system’s continuous operation.

Inspection by NESL Belzona Team

Nicco’s expert service engineers conducted an in-depth inspection of the pump to evaluate the extent of damage. The assessment revealed extensive pitting and corrosion across the pump’s inner casing. The team determined that a traditional repair approach, such as replacing the pump or welding, would be time-consuming and cost-prohibitive. Instead, the team recommended a cold repair solution using Belzona composites. This method was chosen for its proven ability to restore damaged surfaces efficiently and with minimal downtime.

In pump, cavitation occurs when the hydrodynamic pressure exceeds the vapour pressure of a moving liquid. Gas bubbles form within the liquid, which thus becomes a two-phase system. These bubbles will be crushed against the metal surface at high speed, an attack that leads to cavities with rounded contours. This degradation is caused by the combination of a mechanical effect and corrosion of the metal.

Corrosion occurs due to presence of salts in sea water, while erosion occurs due to consistent dynamic activity of sea water (act as erosive agent here) over a period.

Application Situation

The client prioritized three main objectives for the repair:

Restore the pump’s structural integrity and operational efficiency.

Implement a solution resistant to future corrosion and erosion.

Minimize the system’s downtime to maintain production schedules.

Given these requirements, Nicco’s engineers proposed using the Belzona 1311 (Ceramic R-Metal) and Belzona 1321 (Ceramic S-Metal) systems, which are renowned for their durability and performance in aggressive environments.

Application Method

The repair process was meticulously planned and executed as follows:

Surface Preparation:
The corroded and pitted inner casing of the pump was thoroughly cleaned. This included grit blasting the metal surface to an SA 2.5 standard, achieving a surface profile of 75 microns. This preparation step ensured optimal adhesion of the Belzona materials to the substrate.

Repairing the Surface:
Belzona 1311 was carefully applied to fill the pitted and rusted areas of the casing. This versatile composite material is designed to rebuild and restore metal surfaces, providing a strong and durable foundation.

Applying the Protective Coating:
Two coats of Belzona 1321 (Ceramic S-Metal) were applied over the repaired surface. This coating system is engineered for exceptional resistance to erosion and corrosion, making it ideal for environments with high fluid flow and abrasive particles. Its relatively thin film thickness ensures that the pump’s performance is not adversely impacted by flow restrictions.

The Outcome

The repair was completed within the client’s tight outage window, allowing the pump to return to service without disrupting production schedules. The Belzona system restored the pump’s inner casing to its original profile and provided a protective barrier against future corrosion and erosion. As a result:

The pump’s operational efficiency and reliability were fully restored.

The repair extended the pump’s service life, significantly delaying the need for costly replacements.

The client achieved substantial cost savings compared to traditional repair or replacement methods.

Belzona Facts

Belzona 1311 (Ceramic R-Metal):
A highly durable repair composite used for rebuilding and restoring corroded or pitted metal surfaces.

Belzona 1321 (Ceramic S-Metal):
A two-component epoxy-based protective coating designed for high-performance resistance to corrosion and erosion in aggressive fluid flow environments.

Key Benefits:

Rapid application and cure time minimize downtime.

Thin film thickness prevents flow restrictions, ensuring optimal pump performance.

Long-lasting protection extends equipment life and reduces maintenance costs.

This case exemplifies how Belzona composites provide innovative, cost-efficient, and reliable solutions to tackle even the most challenging repair scenarios.

If you have similar challenges or would like to discuss how advanced polymer technologies can benefit your projects, feel free to connect or leave a comment below! 

Corrosion Under Insulation (CUI) Q&A: Solutions for Long-Term Equipment Protection

admin — Tue, 15 Oct 2024 07:32:35 +0000

Introduction: The Urgent Need to Combat Corrosion Under Insulation (CUI)

Corrosion Under Insulation (CUI) is a significant challenge for industries that rely on insulated piping and equipment, such as the oil, gas, and chemical processing sectors. CUI accounts for up to 10% of all corrosion-related costs in these industries and is responsible for 60% of piping failures in refineries. Globally, corrosion is estimated to cost an astonishing $2.5 trillion annually.

The hidden nature of CUI beneath layers of insulation makes it difficult to detect until substantial damage has already occurred. The result? Increased maintenance costs, unexpected downtime, and compromised safety. With these issues in mind, adopting effective CUI prevention and maintenance strategies is critical for companies seeking long-term operational integrity and cost efficiency.

Factors Leading to Coating Failure in Corrosion Under Insulation (CUI) Prevention

Coating failure in systems designed to prevent CUI can occur due to several interrelated factors. Below are the key factors that can contribute to the breakdown of a coating system:

1. Improper Surface Preparation

Why it matters: Surface preparation is critical for ensuring a strong bond between the coating and the substrate. If the surface is not cleaned properly, contaminants like dust, oil, or rust can prevent the coating from adhering correctly.

Common issues: Inadequate cleaning, incomplete removal of rust or old coatings, and insufficient roughening (profiling) of the surface before applying the new coating.

2. Poor Application Practices

Why it matters: Even a high-quality coating will fail if it’s applied incorrectly. Factors such as improper mixing, incorrect application thickness, or failure to follow manufacturer guidelines can all cause premature coating failure.

Common issues: Coatings applied too thinly may not offer adequate protection, while coatings that are too thick may crack. Insufficient drying or curing times can also lead to issues like blistering or poor adhesion.

3. Thermal Cycling

Why it matters: Coatings are often subjected to constant heating and cooling cycles in industrial environments. If the coating lacks the flexibility to expand and contract with the substrate, it may crack, peel, or delaminate over time.

Common issues: Coatings with a high coefficient of thermal expansion that do not match the substrate can be prone to failure during repeated thermal cycling (Courtesy – University of Stavanger).

4. Chemical Exposure

Why it matters: Exposure to harsh chemicals, such as acids, alkalis, hydrocarbons, or salt, can degrade the coating over time. If a coating is not specifically designed to resist the chemicals present in the environment, it will break down more quickly.

Common issues: Incompatibility with aggressive chemicals, particularly in petrochemical or coastal environments (Courtesy –Corrosionpedia).

5. Moisture Ingress and Trapped Water

Why it matters: One of the main causes of CUI is water penetrating the insulation and reaching the substrate. If the coating becomes permeable over time or if there are small breaches, water can become trapped between the coating and the substrate, leading to corrosion.

Common issues: Blistering, underfilm corrosion, and loss of adhesion due to prolonged moisture exposure(Courtesy – Armacell).

6. Mechanical Damage

Why it matters: Physical damage to the coating can occur during installation, maintenance, or regular operation. Once the coating is compromised, the underlying metal is exposed to the environment, increasing the risk of CUI.

Common issues: Scratches, impacts, or abrasion during handling, insulation installation, or due to equipment vibration.

7. Inappropriate Coating Selection

Why it matters: Not all coatings are suitable for all environments. Factors such as temperature, humidity, and exposure to chemicals should all influence the choice of coating. Using a coating not rated for the operating environment can lead to rapid failure.

Common issues: Coatings not designed to handle high temperatures or aggressive chemical exposure breaking down prematurely(Johns Manville).

8. Insufficient Inspection and Maintenance

Why it matters: Coatings require periodic inspection and maintenance to ensure long-term performance. Neglecting regular inspections can allow small defects, like cracks or blisters, to grow into larger issues.

Common issues: Failing to detect and repair early signs of coating failure, allowing corrosion to take hold unnoticed(Corrosionpedia).

To avoid these failure modes, it’s critical to select the right coating for the environment, follow proper surface preparation and application procedures, and perform regular inspections to catch any early signs of degradation.

In this Q&A guide, we’ll explore the key aspects of CUI, the importance of protective coatings, and the factors to consider when selecting and applying coatings to ensure long-term equipment protection.

Q&A: Choosing the Right Coating for Corrosion Under Insulation (CUI)

Q: Why is Corrosion Under Insulation (CUI) such a significant problem in industrial environments?

CUI is a challenging form of corrosion because it often goes undetected until serious damage has occurred. When water gets trapped beneath insulation, it remains in contact with the equipment's surface, accelerating corrosion. The problem is compounded in industries that operate with insulated piping, vessels, or equipment, where fluctuating temperatures cause thermal expansion and contraction, drawing in moisture. Over time, this moisture leads to localized corrosion, which weakens the material and can result in equipment failure, costly repairs, or even hazardous situations.

Q: How do coatings help prevent CUI?

 Coatings play a vital role in preventing CUI by acting as a barrier between the steel surface and any moisture that penetrates the insulation. A high-quality CUI coating provides protection from both external environmental factors and the corrosive reactions that occur when moisture is present. The key is to select coatings that can endure the thermal, chemical, and physical conditions in which the equipment operates. For example, the best CUI coatings resist cracking, handle thermal cycling, and maintain strong adhesion to the substrate, even under challenging conditions like fluctuating temperatures or chemical exposure.

Q: What are the key characteristics to look for in a good CUI coating?

When selecting a CUI coating, the following characteristics are essential:

Thermal Resistance: The coating should be capable of withstanding the operating temperatures of the equipment without degrading. Coatings that can handle both high temperatures and the thermal cycling that occurs during shutdowns or changes in process conditions are crucial.
Moisture Resistance: A good CUI coating should be impermeable to water and vapor. This helps prevent moisture from penetrating to the steel surface, where it could cause corrosion.

Adhesion and Flexibility: High adhesion ensures that the coating remains firmly attached to the steel, even when subjected to thermal expansion or contraction. Flexibility is also important to prevent cracking, which could allow moisture to reach the underlying metal.
Chemical Resistance: The coating should resist the various chemicals commonly found in industrial environments, including acids, alkalis, hydrocarbons, and oils. This ensures the coating continues to protect the surface, even in the presence of harsh substances.
Ease of Application: In real-world conditions, perfect surface preparation isn’t always possible. Look for coatings that can be applied to surfaces with minimal preparation, such as directly over hot surfaces or onto lightly corroded steel, to save time and reduce downtime during maintenance.

Q: Are there coatings that work better in different temperature ranges?

Yes. Different CUI coatings are designed to handle specific temperature ranges, which is crucial for selecting the right solution for your equipment. For instance, in environments where the equipment operates at medium temperatures (30°C to 80°C or 86°F to 176°F), a robust, solvent-free coating can provide excellent protection. These coatings often excel in bonding to grit-blasted or prepared steel surfaces, maintaining strong adhesion while resisting thermal cycling. On the other hand, for high-temperature applications (up to 150°C or 302°F), a heat-activated coating may be more appropriate. These coatings are designed to be applied directly to hot surfaces, curing as they are exposed to heat, and forming a highly durable and corrosion-resistant layer.

Q: How can I ensure the coating will withstand physical stresses, such as impacts or temperature fluctuations?

It's important to choose a coating that has been tested for impact resistance and thermal cycling durability. For example, some coatings can withstand hundreds of thermal cycles without cracking, which is critical for equipment that experiences repeated heating and cooling. Additionally, coatings that demonstrate high impact resistance ensure they remain intact even if the equipment is subject to physical knocks or vibration during operation.

Q: What should I look for in terms of chemical resistance for a CUI coating?

Many industrial environments expose equipment to chemicals such as acids, alkalis, hydrocarbons, and oils. The coating you choose should have strong resistance to these chemicals to prevent degradation.

Q: What testing should a good CUI coating pass to ensure long-term durability?

 Industry standards, such as ASTM B117 for salt spray resistance and ASTM D1002 for adhesion, are commonly used to assess a coating’s performance. A good CUI coating should demonstrate excellent salt spray resistance, with no visible corrosion after prolonged exposure, and strong adhesion, even to less-than-ideal surfaces. Coatings that pass these rigorous tests provide reliable, long-term protection against CUI.

Q: What makes Belzona products particularly effective for CUI prevention?

Belzona coatings, such as those designed for CUI, exemplify many of the desirable characteristics mentioned earlier. These products have been rigorously tested for thermal cycling, impact resistance, and chemical durability, making them well-suited for industrial environments. For example, Belzona’s heat-activated coatings perform exceptionally well in high-temperature applications, with strong adhesion even on surfaces with minimal preparation. Additionally, their solvent-free, two-component coatings provide excellent protection in medium-temperature environments, offering robust chemical and corrosion resistance.
While every facility's needs will differ, choosing a coating with these superior parameters ensures long-lasting protection against CUI, minimizing downtime and extending equipment life.

Q: How do I know if a coating is suitable for insulated equipment?

Check if the coating has been designed for use under insulation and if it withstands moisture and heat retention. Ensure it meets key performance indicators like salt spray resistance, adhesion to steel, and impact strength.

Q: How important is salt spray resistance for a CUI coating?

Salt spray testing simulates corrosive environments to see how well the coating resists corrosion. Coatings that show no signs of corrosion after 1,000 hours of salt spray testing are highly reliable for long-lasting protection.

Q: Can I apply a coating to hot equipment, or does it need to be shut down?

Some coatings are designed for direct application onto hot surfaces, making it unnecessary to shut down equipment. These coatings begin to cure when they reach the required temperature.

Q: What about coatings for high-temperature equipment?

For high-temperature systems, use coatings that remain stable up to 150°C (302°F) and have high dry heat resistance to avoid degradation over time.

Q: Can these coatings be applied to rusty or partially corroded steel?

Yes, some coatings bond well even when the surface is not perfectly clean, such as rusted steel. While ideal surface preparation is recommended, these coatings can still deliver strong adhesion and corrosion protection.

Q: How do I ensure the coating will last long-term?

Regular maintenance and proper application are key. Choose a coating that’s been tested for chemical resistance, thermal stability, and impact strength. Perform routine inspections to ensure the coating remains intact.

Q: How does thermal cycling affect the performance of coatings?

Thermal cycling can cause expansion and contraction of the equipment, stressing the coating. A good CUI coating should be tested for thermal cycles and maintain its protective properties without cracking or peeling.

Q: What other factors should I consider when selecting a CUI coating?

In addition to the product's performance characteristics, consider the ease of application, the required cure time, and the specific environmental conditions of your facility. Coatings that can be applied during normal operations (for example, directly to hot surfaces) can save significant time and reduce the need for equipment shutdowns. Likewise, coatings with a fast cure time can allow you to return equipment to service more quickly.

Some Examples of Belzona Application on CUI

Overall, selecting the right CUI protection requires understanding your facility’s specific challenges and choosing a coating that combines durability, flexibility, and chemical resistance with ease of use. For more tailored recommendations, consult with a supplier who understands both the demands of your environment and the capabilities of modern CUI protection technologies.

References

https://www.jm.com/en/blog/2017/march/nace-study-estimates-global-cost-of-corrosion-at-25-trillion-annually/

https://www.corrosionpedia.com/understanding-the-causes-and-cures-for-corrosion-under-insulation/2/7297

https://www.uis.no/en/faculty-of-science-and-technology/corrosion-under-insulation-one-of-the-largest-integrity

NICCO is the sole distributor in India, Bangladesh, Nepal and Bhutan for Belzona® range of Cold Repair Polymeric Compounds, produced at the advanced facilities of Belzona® Polymerics Ltd., U. K., an ISO 9001:2008 & ISO 14001:2004 certified company.
The company has ready access to the latest technological breakthrough that helps to meet the increasingly stringent demands of modern industry.