Problem: Recurrent Leakage in Pressurized Water Pipelines
In April, VIVABLAST completed a repair project on DN600 and DN900 potable water pipelines for SWIC in Ho Chi Minh City.
The pipelines had previously been repaired using hot welding. While this method temporarily sealed visible defects, leakage reoccurred shortly after the system returned to operation. This pattern is common in pressurized water pipelines where structural damage already exists.
Hot welding introduces localized high temperatures, causing repeated expansion and contraction at weakened areas. When combined with continuous internal water pressure, these thermal stresses accelerate crack propagation, making recurrence almost inevitable.
In potable water systems, repeated leakage is not merely a maintenance issue—it directly impacts safety, regulatory compliance, and operational continuity.
Why Hot Welding Underperforms in Potable Water Systems
From an engineering perspective, hot work repairs are inherently mismatched with pressurized pipelines due to three factors:
- Thermal stress concentration at damaged pipe sections
- Cyclic pressure loading during operation
- Material fatigue acceleration caused by heat input
These conditions explain why welded repairs often fail prematurely, even when executed correctly.
The Solution: Cold-Applied Composite Repair with Belzona 1111
To eliminate the root cause of failure, VIVABLAST applied a cold-applied composite repair system using Belzona 1111.
Unlike hot welding, Belzona 1111 is applied at ambient temperature, eliminating thermal input entirely. The material chemically bonds to the substrate and cures into a high-strength, chemically resistant composite layer that both seals the defect and structurally reinforces the pipe.
Key technical advantages include:
- No heat-affected zone
- Minimal structural stress on existing pipe material
- High adhesion under wet and pressurized conditions
Crucially, Belzona 1111 is NSF and WRAS certified, making it suitable for potable water applications where material safety is non-negotiable.
Measurable and Sustainable Results
Following application and curing, the pipeline returned to full operation without leakage or pressure loss.
Results achieved:
- Complete elimination of leakage
- Improved structural integrity of damaged sections
- Zero interruption to plant operations
- Reduced risk of future crack recurrence
When Cold-Applied Repair Is the Right Choice
Cold-applied composite repairs such as Belzona 1111 are technically superior to hot welding for pressurized potable water pipelines. By removing thermal stress from the repair process, they significantly reduce failure recurrence while extending pipeline service life.
For facilities prioritizing safety, compliance, and long-term asset reliability, cold-applied repair should be considered a primary solution—not a temporary fix.