The Problem

A 24” engineered steel watermain, which was previously protected with cold applied tape, encountered an unforeseen accident. It was struck by a fiber optic directional bore, causing a score at the bottom of the pipe. Over time, the damaged area succumbed to corrosion, and rust permeated through the steel, leading to the need for urgent repair to prevent water loss and maintain service integrity.

The Substrate

• CA6 Bedding with a FA6 backfill: A standard for underground piping, providing a stable base and proper drainage.
• Steel Pipe: The primary material of the watermain, known for its strength but also vulnerability to corrosion when damaged.

The Solution

The repair process required immediate and effective action:

1. Pipe Assessment and Removal: A section measuring 13 feet of the damaged 24” steel watermain was meticulously cut out. This section contained the area that was struck and had since rusted through.
2. Pipe Replacement: A new 13-foot section of steel pipe coated with fusion-bonded epoxy was prepared. This type of epoxy coating is known for its corrosion resistance and is often used in pipelines for its robustness.
3. Welding and Securing: The new pipe section was securely welded into place with new butt straps. These straps served to connect the new section seamlessly to the existing pipeline infrastructure, ensuring the structural integrity of the watermain.
4. Corrosion Protection Application: After the welds were completed, Viscotaq ST, a visco-elastic sealant tape, was wrapped around the welded seams. This product is chosen for its outstanding adhesion properties and its ability to prevent water ingress and corrosion.
5. Outer Protection: To provide additional protection and mechanical strength, a PVC Outerwrap was applied over the Viscotaq ST. Measuring 6 inches by 100 feet, this outerwrap ensured that the entirety of the repair site was shielded from environmental factors.

Products Used

• Viscotaq ST 12”x33’: A visco-elastic sealant tape providing a strong, water-resistant bond over the welded areas.
• PVC Outerwrap 6” x100’: Serves as the final protective layer to the repair site, enhancing durability.

The Outcome The emergency repair of the 24” steel watermain was executed swiftly and effectively, minimizing service disruption and preventing extensive water loss. The combination of Viscotaq ST and PVC Outerwrap ensured a watertight and corrosion-resistant seal, restoring the integrity of the watermain. This solution not only rectified the immediate problem but also contributed to the long-term reliability of the water distribution system, a vital resource for the community served by the water plant.

For durable and reliable watermain repair solutions, Unconventional Solutions offers the expertise and high-quality products necessary to address even the most challenging pipeline issues. If your infrastructure requires expert attention, contact us to ensure a swift and robust repair.