Barwon Water, Victoria’s largest regional urban water corporation, provides services to more than half a million residents during peak holiday periods. Interflow was engaged by Barwon Water to undertake their Major Sewer Relining works, rehabilitating 7.8km of gravity main over the course of the program.

The mild steel cement-lined pipeline DN900 PN12 runs underneath a busy street and has two Lining works were performed using Interflow’s patented Expanda solution, a full-bore spiral-wound liner that restores the structural integrity and reliability of ageing pipelines. CCTV inspections were performed before and after lining to plan and inspect the quality of works.

Under the rehabilitation program, Interflow needed to reline a 237m section of pipeline that ran under a busy rail yard. A vital access chamber was buried under live tracks, and disrupting rail services to access the chamber was not an option.

Thinking outside the box, the local crew identified a Remote Point Expansion kit in stores at Interflow’s Sydney headquarters. The innovative machine performed task of sealing and securing the liner at the access chamber junction without man-entry into the chamber.

Installing three liners at once required custom-built connections, designed by Primus Line and By embracing bespoke technology, the delivery team successfully relined the challenging section of pipeline, restoring it to optimum structural integrity and performance. This is one of many important sewer assets relined and restored under the program, supporting Barwon Water in their delivery of safe, reliable wastewater services to their community.

The challenge

While Interflow’s patented Expanda technology provided Barwon Water with a robust and reliable rehabilitation solution, delivering the lining program was not without its challenges.

A 237m section of DN450 pipe was located under a rail yard housing Victoria’s V-Line rail fleet. The access chamber was buried under live tracks along the rail corridor, inhibiting the team’s access to the sewer assets. Exposing the access chamber would have caused major disruptions to the regional rail service for several weeks while works took place.

Adding to the challenge, the alternate access point was over 80 metres downstream, and a sharp bend at the chamber site prevented the crew from simply lining through the chamber.

The solution

Interflow crews took the unexpected challenge in their stride and quickly got to work on a practical Taking the challenge in their stride, the team worked to find a trenchless lining solution for the difficult section of sewer.

Unable to enter the access chamber, the crew needed an alternate way to seal and render the ends of the liner to the host pipe. Interflow’s Sydney team was in possession of a Remote Point Expansion kit that could connect to the robotic pipe cutter and traverse the pipe, following the Expanda liner and securing it at the buried access chamber.

Using this innovative technology, Interflow installed two DN450 liners through the access chamber in a single day, restoring the section of sewer main to its peak performance.

Conclusion

Traditional dig-and-repair methods can have a significant impact on the community and the Reliable and robust wastewater systems are critical to the health and hygiene of our communities.

When faced with access restrictions during a major sewer lining program, Interflow rose to the challenge and identified a bespoke, remote-controlled solution that could take perform the works without the need for man-entry.

By harnessing this innovative technology, the delivery team was able to restore an ageing section of pipeline without disruption to Victoria’s regional rail network.