Gate Valve Pipe Rehabilitation
Restoring Structural Integrity and Leak Prevention in a Critical Cooling System
At a major power plant, Gate Valve Pipes (GVPs) play a crucial role in the cooling water system by regulating the flow of water through the main cooling water header. These pipes function as “gates” that can close to restrict water movement when necessary.
Over time, the GVPs had severely corroded, becoming structurally compromised with through-wall failures and leaks. Due to project timelines, full replacement was not a viable option, and a rapid, long-term rehabilitation solution was required.
Experience always overcomes challenges
The pipes had degraded to the point of failure, requiring a solution that could restore strength without full replacement.
Work had to be completed without extended downtime, ensuring the plant’s cooling water system remained operational.
Inspection and Preparation
CFES implemented a comprehensive approach to inspection and preparation:
Condition Assessment:
Inspection revealed severe external corrosion, leaks, and structural weakness in the GVPs.
Through-wall failures were identified as critical areas requiring immediate reinforcement.
Surface Preparation:
SP-5 Grit Blasting was performed to remove corrosion and create an optimal bonding surface for CFRP application.
The pipes were cleaned and dried thoroughly to ensure maximum adhesion of the composite system.
Innovative Repair Methods
Advanced materials and techniques were employed to ensure reliable and durable repairs:
Carbon Fiber Reinforcement:
CFES wrapped the external surface of the GVPs with high-strength CFRP, providing:
Structural reinforcement to restore mechanical integrity.
Leak-tight sealing to prevent further water loss.
Chemical-Resistant Epoxy Liner:
A chemical-resistant epoxy coating was applied for:
Long-term durability against environmental and operational stresses.
Additional leak prevention and enhanced resistance to cooling water exposure.
Key Outcomes
Structural Integrity Restored: CFRP reinforcement successfully stabilized the pipes, eliminating the need for costly and time-consuming replacement.
Leak-Tight Performance: The applied system sealed through-wall failures, preventing water loss and ensuring continuous system operation.
Minimized Downtime & Cost Savings: The rehabilitation was completed on schedule with no major plant disruptions, providing a cost-effective alternative to pipe replacement.
Long-Term Durability: The solution delivered a maintenance-free, long-lasting repair, ensuring continued performance under harsh operating conditions.
