Severn Trent have become the first water company in the world to trial Melt in Place Pipe (MIPP) as a method of repair on a commercial water network.
The trial took place on pipes suffering from corrosion in the region of Severn Trent’s sister company, Hafren Dfrdwy. MIPP is now expected to be given approval for wider testing across the Severn Trent network.
If successful, it could transform the way that water organisations renew older pipes and repair leaks and bursts.
MIPP is a trenchless pipe installation technique developed by Aqualiner – a specialist pipeline technology company based in Leicestershire – in conjunction with Severn Trent, Yorkshire Water, Anglian Water and Essex Water.
It involves pulling a new liner made of glass fibre reinforced Polypropylene through an existing pipe. The liner is heated to 200°C via an element attached to a device called a pig.
The pig is pulled along inside the pipe at a controlled speed by an inversion bag, which also moulds the new liner against the wall of the original pipe.
At 3mm thickness, the liner is thin enough to minimise any loss of hydraulic capacity. At the same time, it is strong enough to withstand the internal pressures and external loads underground pipelines operate under.
Relining using MIPP can extend the lifespan of a pipe by up to 60 years. Once the new lining has been installed and cooled, the pipe can be rapidly returned to service. The result is the equivalent of replacing the pipe but without the need to excavate the old line.
Jamie Perry, innovation trials lead at Severn Trent, said: “Currently, our main option is to renew leaky pipes by digging them up and replacing them.”
“Aqualiner has the potential to fully line a pipe with reduced excavations and less time on site. Ultimately, this means our customers experience less disruption.”
Pipe repair is a major issue facing the United Kingdom. 2,954 million litres of water were lost on the public supply network in 2019-20 with the water industry subsequently pledging to cut current leakage levels by 50 percent before 2050.
MIPP has the potential to play a major role in achieving that target, making leaking pipe repair easier and allowing water companies to strengthen existing lines before they burst or require replacement.
Aqualiner now plans to develop MIPP further, producing contractor-ready equipment capable of relining larger pipes between 100mm and 300mm in diameter.
This would allow engineers working on behalf of water companies to reline the biggest pipes on the network far more quickly and easily than is currently possible.