SPI Coatings: Non-Shielding Below Grade Insulative Coating System

The Challenge: Cathodic Shielding and Corrosion Under Insulation (CUI)

For decades, the pipeline industry has battled a hidden enemy: Cathodic Shielding. Up to 85% of all external pipeline corrosion occurs under disbonded, CP-shielding coatings. Conventional below-grade insulation materials, such as concrete and metal jacket systems, frequently lead to severe Corrosion Under Insulation (CUI).

When these traditional systems fail, they trap moisture against the pipe while simultaneously blocking the cathodic protection current from reaching the steel. This creates a highly corrosive environment that is incredibly difficult to detect without costly excavations. The industry urgently needs a solution that provides effective thermal insulation without compromising pipeline integrity.

The Solution: A Revolutionary Dual-Purpose Coating

Developed in cooperation with the largest interstate pipeline operator in the U.S., SPI Coatings has engineered a groundbreaking solution: The Non-Shielding Below Grade Insulative Coating System.

This innovative system is specifically designed to tackle the challenges of underground infrastructure, such as fuel gas heater lines, glycol water piping, and biodiesel lines. It acts as a dual-purpose barrier, providing both effective thermal insulation and enhanced corrosion protection by ensuring that cathodic protection currents can reach the pipe surface.

How it Works

The SPI Coatings solution is a multi-layered system designed for maximum performance and durability:

1. Base: Applied over standard Fusion Bonded Epoxy (FBE) or any cathodic disbondment-rated primer.
2. Insulation Core: An advanced acrylic-based thick film insulative coating (HPC® Coating).
3. Structural Reinforcement: Wrapped in a proprietary polyester mesh to provide rigidity and structural strength without sacrificing CP compliance.
4. Sealant: Top-coated with a marine-grade epoxy to seal the entire surface against water ingress.

Crucially, both rigorous laboratory testing and extensive field trials have proven that this composite coating system does not cause cathodic shielding.

The Game Changer: Controlled Shop Application

One of the most significant advantages of this new system is the application method. Unlike traditional insulation that is painstakingly installed in the field under challenging environmental conditions, the SPI Coatings system is designed for controlled shop application.

Benefits of Shop Application

• Eliminates Variables: Stop fighting the elements. Shop application removes weather-related delays and quality control issues.
• Consistent Quality: Delivers a perfect, controlled coat every single time, ensuring the system performs to its exact specifications.
• Ready for Installation: Pipes, tanks, and vessels are delivered to the site pre-coated and ready to go into the ground.
• Fast Turnaround: Significantly reduces open trench durations, excavation needs, and on-site labor requirements, leading to faster project completion and enhanced job site safety.

Optimized for Rapid, Non-Destructive Inspection

Maintaining asset integrity requires ongoing monitoring. The SPI Coatings system is uniquely designed to support modern, cost-effective inspection strategies that eliminate inefficient “blind” or time-based digging programs.

• Non-Intrusive Screening (LRUT): The system is fully compatible with Long Range Ultrasonic Testing (LRUT). This allows operators to rapidly screen hundreds of feet of pipeline from a single, minimal excavation point, identifying areas of interest and minimizing unnecessary digging.
• Through-Coating Measurement (PEC): Pulsed Eddy Current (PEC) technologies can be utilized to obtain quantitative average wall thickness measurements directly through the coating, avoiding the need for costly coating removal.
• Reusable Inspection Ports: For precise visual inspection or Phased Array Ultrasonic Testing (PAUT) over critical areas like weld joints, inspection “windows” can be easily cut into the thick film coating. Once the inspection is complete, the cutaway square is simply placed back and sealed with silicone until the next inspection cycle.

Benefits to Asset Owners

The Non-Shielding Below Grade Insulative Coating System offers a comprehensive suite of benefits designed to protect assets and improve the bottom line:

• Prevents Cathodic Shielding: Ensures your CP systems work as intended, protecting your infrastructure.
• Mitigates CUI: Replaces problematic conventional jacket insulation, drastically reducing the risk of hidden corrosion.
• Superior Thermal Performance: Effective insulation for a variety of fluids, from freeze protection to maintaining process temperatures.
• Drastically Reduced Inspection Costs: Enables advanced NDT screening and targeted excavations.
• Long-Term Cost Savings: Reduced on-site labor, faster installation, less excavation/shoring, and extended asset life.
• Award-Winning Innovation: This technology has been recognized for Energy Star for excellence in performance and CUI protection.