Sanexen’s Aqua-Pipe® cured-in-place pipe (CIPP) liner has been used in what it says is Australia’s first structural reline of a drinking water main. Ventia, one of Australasia’s largest infrastructure service suppliers, applied the liner to an at-risk 50-year-old water main located under a busy railway line for one of the country’s largest water utilities.
Sanexen’s structural liner for drinking water mains, Aqua-Pipe, has made its way to Australia and been used in the ground-breaking pipeline rehabilitation for a local water utility. The project was completed by local services company Ventia, who has the exclusive rights to Aqua-Pipe in Australia; it is the first time a structural CIPP product has been used to reline a drinking water main in Australia.
Ventia was awarded the contract for the pipeline rehabilitation by Queensland Urban Utilities, one of Australia’s largest water utilities, which operates and maintains an 18,000 km network of water and sewerage pipes in South East Queensland. The network includes a concrete-lined cast iron and mild steel DN 300 water main in Brisbane, running under three railway tracks inside a Queensland Rail easement.
The pipe was laid in 1966 and had failed at one end of the pipeline in 2012. Queensland Urban Utilities conducted a condition assessment on the pipeline which concluded that the four 45° bends posed a continuing risk of further failures with substantial consequences of disruption as they were known to be corroded and were located outside of the concrete encased section.
If the water main failed at one of the 45° bends, it would disrupt water supply and interrupt services for commuters and freight trains. Emergency repairs would be difficult because of the operational requirements of works within the rail corridor. After considering its options, Queensland Urban Utilities elected to rehabilitate the pipe to improve the reliability of the supply and minimise the risk of failure.
“In considering the option to rehabilitate the cast iron elbows, Queensland Urban Utilities compared the traditional method of replacement with other options including relining the entire section of main,” says Queensland Urban Utilities Project Manager David Fox.
“Relining the main was concluded to be a superior option because it could be completed from outside the rail corridor, addressed the latest requirements for pipes under rail, and in less time than other methods.
“It also meant that the main under the railway was relined in the process while retaining the existing encasement, which provided added security to both Queensland Urban Utilities and Queensland Rail,” says Mr Fox.
Ventia isolated the existing main in accordance with a shutdown plan issued by the operator. The main was cleaned and inspected using CCTV, which confirmed that the pipe required renewal. Once the pipe was cleaned, the Aqua-Pipe liner was impregnated with a thermoset resin, then pulled through the host pipe. The liner was then formed to the host pipe using a foam pig and cold water under pressure.
Hot water was then pumped through the liner to start the curing process. Once the curing process was completed CCTV inspection confirmed that the liner had properly bonded to the host pipe. The whole process from cleaning to curing took less than eight hours to complete.
With the capability to withstand a short-term burst pressure 27.57 bar (2,750 kPa), Aqua-Pipe met the utility’s pressure testing requirements for a newly installed water main. The pipe passed Queensland Urban Utilities’ benchmark and, once the bacteriological test results showed the pipe had been adequately cleaned and new thrust blocks were installed, the main was de-isolated and returned to service.
“We’re really proud of the innovative solution we have been able to deliver to our client Queensland Urban Utilities, which avoided any disruption to train commuters,” says Ventia Renewals Contract Manager Ryan Bickerton.
“Our solution, with Aqua-Pipe, allowed us to work within the existing water main without disrupting rail services and renew the pipe with structural integrity, from outside the rail corridor. To be responsible for the first CIPP application for a drinking water main is a great achievement for Ventia and everyone involved. Later in 2017, we will be completing a 1,100 m installation of Aqua-Pipe for a utility in Melbourne, Victoria who has also demonstrated a strong interest in CIPP renewal solutions for the rehabilitation of their drinking water infrastructure.”
While the Aqua-Pipe liner might be a new name to the Australian market, it is well known in the North American relining industry, with over 1,500 km successfully installed in Canada and the US. It can be applied to asbestos cement, mild steel, ductile iron, cast iron and PVC pipes where a trenchless structural liner is required.
Aqua-Pipe has been successfully tested against Australia and New Zealand’s standards AS/NZA 4020-2005, as a product for use in contact with drinking water. It is also certified by NSF to NSF/ANSI Standard 61, UL, BNQ3660-950 and WRAS approved product (BS6920).
About Aqua-Pipe liner
Manufactured in Canada by Sanexen, Aqua-Pipe is a proven economical and viable Trenchless Technology alternative to excavating and replacing deteriorated water pipelines. It is a structural liner designed and manufactured with mechanical properties that exceed all specifications and meet drinking water requirements in several countries, including the UK, US, Canada and Australia, where Ventia holds the exclusive licence to the product.
This article was featured in the Fall edition of Trenchless International. To view the magazine on your PC, Mac, tablet, or mobile device, click here.
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