Online Cooling Water Leak Repaired with Belzona Composite Technology
A critical cooling water pipeline at a prominent refinery developed an active leak from a heavily corroded flanged connection. The line was operating at approximately 8 kg/cm² pressure and 50°C, making immediate intervention necessary to prevent further loss of cooling water and avoid disruption to plant operations.
Visual inspection showed extensive external corrosion across the flange, bolts, adjoining pipework, and bend. Water was escaping under pressure from the joint area, while the surrounding metal surfaces displayed significant rusting, scaling, and coating deterioration.
The Challenge
A conventional repair would have required isolation, depressurisation, cutting, welding and replacement of the damaged section. To minimise downtime, the client required an online, cold-applied solution capable of controlling the leak and reinforcing the weakened connection.
The Belzona Solution
A specially designed 304 stainless-steel strip system was installed to provide mechanical restraint and control the active leakage. The affected area was then reinforced using:
- Belzona 1161 (Super UW-Metal)
- Belzona 9341 Reinforcement Tape
The repair followed a site-engineered adaptation of Belzona Know-How System Leaflet VPF-11a for high-pressure pipe repairs.
Surface Preparation and Application
Loose rust, scale, failed coating and other contaminants were removed using hand and power tools. Surface preparation was not possible due to thinning of the pipeline surface.
Belzona 1161 was mixed at:
- 2:1 by volume
- 4:1 by weight
An initial layer was pressed firmly into the prepared surface to fill corrosion pits and improve substrate contact. Belzona 9341 was then saturated with Belzona 1161, wrapped around the repair area with suitable overlap and fully encapsulated with an additional layer of material.
The external substrate temperature was verified before application because Belzona 1161 has a published application range of 5°C to 40°C. At a surface temperature of approximately 40°C, the system required around 12 hours before full mechanical or thermal loading.
Safety and Quality Control
The work was carried out under the site’s permit-to-work procedure with a task-specific risk assessment, controlled access, suitable PPE and continuous coordination with plant operations. No welding or hot work was required.
The completed repair was inspected to confirm secure reinforcement, full encapsulation, sound edges, absence of visible voids and control of the leakage.
The Result
The combined stainless-steel and Belzona repair system successfully controlled the cooling water leak and reinforced the corroded connection without immediate pipeline replacement.
The client benefited from:
- Online leak control
- No hot work
- Reduced shutdown requirements
- Faster maintenance response
- Reinforcement of the damaged pipeline connection
Conclusion
By combining a 304 stainless-steel strip system with Belzona 1161 and Belzona 9341, the maintenance team delivered a practical cold-repair solution for a critical cooling water leak under demanding operating conditions.
