As water infrastructure ages, pressure pipes have traditionally been excavated for repair or replacement. This has disrupted communities and increased costs and time scales.
“The Water Services Association of Australia (WSAA) found that in Australia, there is around 40,000 kilometres of asbestos cement pipe,” says Will Zillmann, Interflow’s National Product Manager.
“When you dig it up, a lot of precautions have to be taken, so the expense is significant. If you leave it in the ground and lay new pipe alongside it, you have to make sure nobody ever digs it up, which adds more administration expense. There are a lot of issues.”
As corrosion from aggressive soils attacks underground pipes, including those made from cast iron, a trenchless renewal option for such pipelines becomes increasingly attractive.
Comprehensive renewal solutions should not just fix a specific problem, Zillmann says, but should reset the lifespan of the pipeline. They should essentially perform as a new product.
“Proactive trenchless renewals are one of the keys to defending our critical water and wastewater services in a sustainable and cost-effective way,” Zillmann says. “New or rehabilitated pipes can last decades, reducing the need for frequent interventions.”
“Our objective was to build a suitable suite of proven solutions that enable us to match the right product or approach to the pressure pipeline’s condition, material, size and location.”
In response to the threats raised by the much-discussed infrastructure cliff, and by the fact that a significant percentage of Australia’s water reticulation networks are made from asbestos cement, Interflow developed the Rediflow bundle.
Rediflow includes their Titeflow die-reduction lining as well as Infrastop line-stopping technology.
Together, the innovations provide a complete reticulation renewal system that empower asset owners to conduct proactive renewal projects, dramatically reducing unexpected network shutdowns.
The Rediflow bundle is at the core of Interflow’s suite of solutions, and includes a polyethylene liner technology known as Titeflow.
It’s a structural liner that has its diameter reduced with a die during installation, so it can be drawn into the host pipe. Once inside, it expands again to press against the host walls, creating a new pipe within the existing pipeline.
As a lining technology, it fits within the ISO classifications for trenchless solutions, primarily at Class A (can survive failure of host pipe and is a fully structural solution).
It’s a solution that balances performance, safety and environmental impact, with the many benefits including:
As the triple bottom line of environmental, social and economic impacts becomes increasingly important to water authorities and government, sustainable pipeline renewal methods will become the norm, Zillmann says.
Interflow’s purpose is to improve lives, which extends to the communities and environments they operate within. This has led them on a journey to find, assess and develop renewal solutions that are sustainable and support the needs of the industry, customers and their communities.
On this journey, and to ensure the trenchless solutions do what they promise, Interflow ran an exhaustive and ongoing research project.
“To enable renewal programs and decrease the reliance on excavating and replacing ageing pipes, the water industry has been searching for renewal solutions specifically optimised for pressure pipelines that meet the needs of asset owners and their communities.”
“We were active participants in WSAA’s Cooperative Research Centre for Smart Linings for Pipe and Infrastructure Project,” Zillmann says.
This involved water authorities, suppliers and delivery partners collaborating over several years to research and trial the effectiveness of emerging lining technologies for water and wastewater assets.
“This type of industry-led research is critical for objectively assessing technologies that are entering the Australian market for effectiveness and suitability … and for creating product documentation and decision tools,” he says.
Through such research projects, and by working closely with customers, Interflow has been able to push the boundaries of common approaches like slip lining and large diameter die-reduction lining.
“For example, we’ve had success renewing longer lengths of water main using both of these technologies by thinking differently about how we store, string out and weld pipe sections, and how we facilitate insertion,” Zillmann says.
“As a result of these approaches, we can now offer renewal options for pressure pipes in varying condition states and covering a large range of sizes and materials. Our approach to renewal opportunities is to be solution-agnostic and develop an optimal methodology based on project-specific network capacity needs, pipe condition and material, internal diameter, access constraints, budget and community needs.”
Interflow’s research led to the use of the trenchless pressure pipe solution in real projects, which further added to the data-set utilised to inform the algorithm that predicts such information as pulling load, die size, insertion diameter, and more.
“The algorithm is where the real magic is,” Zillmann says. “If you get it right, by the time you get to the site everything is relatively easy.”
Of course, there is always room for greater performance and more innovation, which is why the project is ongoing.
“We’re always working on optimising the performance of the solution, because its main drawback is that it naturally reduces the diameter of the pipe,” he says.
“That can have an impact on flow capacity. But as long as we keep working on the materials and the algorithm, we can reduce that effect as much as possible.”
