Titeflow supports trenchless technology in projects

When it comes to minimal community impact, trenchless technologies are often sought after. That was the case when Interflow came on board for a challenging project.

When it comes to minimal community impact, trenchless technology is often sought after. That was the case when Interflow came on board for a challenging project.

Hunter Water reached out to Interflow to help deal with a water main that had failed at several points in Rutherford, near Newcastle, NSW. The pipe ran under a well-established and built-up industrial area with substantial traffic flow. While the water main was isolated, network capacity was reduced. This was an untenable situation, hence the call to Interflow.

The pipe ran under multiple properties, so digging up the whole pipe would disrupt the businesses affected. It’s why a trenchless solution was sought, as it would maximise the residual value of the water main.

Titeflow is Interflow’s die-reduction close-fit lining system which installs a brand-new HDPE water pipe. This offered cost benefits over other rehabilitation alternatives and would result in an acceptable internal diameter.

Allan Moran is the Hunter Region Delivery Manager for Interflow. He was in charge of what turned out to be a mammoth task.

“Titeflow works by pulling a standard HDPE water pipe through a static die, temporarily reducing its diameter,” said Moran. “Whilst under tension, it’s then pulled through the host pipe. Once the new pipe is in place, the pulling load is released, and the pipe reverts to near its original diameter. This means it fits tightly against the host pipe and provides the maximum potential internal diameter. With a wall thickness of 48 millimetres, extreme force was needed to winch all 560 metres of pipe into its place and stretch it through the static die – 85 tonnes in total.”

New records

At 560 metres, this was the longest single installation of Titeflow that Interflow has ever installed. It nudged out the previous record of 550 metres in 2014. Interflow has completed many Titeflow installations using similar diameter pipelines and is using this experience to install longer lengths in single pulls.

Hunter Water and regional and local councils were invited to watch the installation and the die-reduction process, see a record-breaking pull, and further their understanding of this process.

“We had people from Liverpool Plains, Port Macquarie, and other local government authorities from the region,” Moran said. “It was a great opportunity to teach them what we do and how Titeflow works. One thing we had to show was the extension of the pipe as we pulled it through. There was an extra 42 metres in stretch that returns to size once the tension is removed from the pull.”

Longer installation lengths mean fewer excavations and shorter project durations, which can, in turn, mean fewer traffic disruptions, reduced environmental risk, and minimal community fatigue. The success of this project proves to the water industry that long lengths of new pipe can be installed with minimal community disruption.

Innovations meet challenges

There were challenges associated with this project. Moran spoke about a few of them.

“The existing water main and easement transected the industrial parcels,” he said. “Replacing the water main by trenching in the existing alignment would have resulted in the closure of several businesses during the construction period. That was not an option.”

There would have been considerable pavement and fence restoration costs if an open-cut approach had been adopted. There had already been several pipe failures, so a key project driver was to rehabilitate the pipe without further impacting business operations.

“It’s why Hunter Water wanted to investigate trenchless technology for rehabilitating the pipe,” said Moran. “They wanted to reduce the community impact of this project.”

What makes this project different from other trenchless rehabilitation projects is the sheer length of the installed HDPE pipe. To avoid interrupting business operations, the entire length needed to be rehabilitated in one pull.

“Once the pipe’s diameter exceeds 180 millimetres, it can no longer be spooled,” he said. “This means the entire length of pipe needs to be delivered in sections, welded together, and laid out flat before installation. The total length of Titeflow that can be installed is usually limited by the space available to string the pipe out. The longer the length, the greater the potential to disrupt the community or to run out of space to store the pipe.”

As part of this project, the new water main could be strung out next to a nearby creek before installing it into the pipeline. That ensured minimal disruption and made Titeflow the most cost-effective trenchless solution.


Following the completion of the project, the water main has been returned to service with confidence that it will not fail. This will allow Hunter Water to meet water demands in the near future. The rehabilitation of the water pipeline has reduced the short-term water continuity risks, while an expansion of the water mains is under design and delivery.

“Utilising trenchless technologies to rehabilitate ageing infrastructure has negated many of the construction risks associated with traditional trench and lay,” Moran said. “The construction footprint, including the requirement for stockpile and sediment and erosion control, is significantly reduced. Since the water main was first installed, heavy commercial development has occurred in the area. Given the nature of the site, the established industrial businesses had considerable hardstand within their yards. Titeflow was able to negate the expensive restoration of brownfield sites.”

The chosen rehabilitation solution was also the most economical. This meant cost benefits for Hunter Water and for their end users. Any solution that required extensive or multiple excavation points would have come with a substantial cost. By choosing a trenchless method, disruption and capital costs were minimised.

“Titeflow had a 20 per cent cost benefit versus other proposed trenchless solutions,” he said. “From our perspective, we had to think outside the box to complete this project, and now we know we can perform these sorts of long pulls.”

“Longer pulls open opportunities to reduce the social, environmental and economic impacts of watermain rehabilitation.”

For more information, visit: www.interflow.com.au

Related Articles:

Send this to a friend