For more than 20 years, technology and construction company SEKISUI Pipe Rehabilitation (SPR) Europe has been offering cost-efficient and technologically superior solutions for the renewal of decaying water and gas pipelines. In addition to local authorities, electricity generators all over the world are now utilising the advantages of trenchless pipe rehabilitation.
A new cure for power plants
SPR Europe combines cured-in-place pipe (CIPP) technology experts and construction companies under one roof. SPR can maintain and renew the underground infrastructure of local authorities and facilities worldwide through the rehabilitation of pressure conduits and sewers. The technologies, however, are now proving themselves in another market: the rehabilitation of cooling water pipes in power plants.
In a sensitive environment such as power plants, the rehabilitation of pressure pipes and ducts are subject to strict quality controls. In Europe the CIPP method with the NORDIPIPE and TUBETEX liners satisfies the strict criteria for the rehabilitation of sensitive infrastructure, for example, drinking watermains or cooling water pipes in power plants.
With certain precautionary and preparatory measures, the method of installation of the liner is identical to the rehabilitation of subterraneous infrastructure in the public sphere. The liner is impregnated with special resins in the old pipe and thermal curing is used to form a new pipe.
Providing corrosion protection in West Burton, UK
One of the first CIPP rehabilitation projects in a power plant took place at West Burton in Nottinghamshire, Great Britain, in January 2012. The plant is operated by EDF Energy, one of the UK’s largest energy companies, and supplies approximately 1.5 million households with electricity from its coal-fired and combined cycle gas turbine power station.
To guarantee proper cooling of the three 430 megawatt gas turbines and protect the cooling water pipe against corrosion and encrustation for decades, EDF Energy entrusted the pipe lining to the Italian construction company Idroambiente. The sensitive surroundings meant a trenchless construction would be required. Given the tight timeframe and significant challenge posed by 90 degree elbows in the bonna cooling pipe, TUBETEX liner was the technological solution of choice.
On 3 January 2012, the team of experts from Idroambiente and its German subcontractor UNIROR started cleaning the six 500 mm diameter supply and discharge pipes. The pipes were cleaned in units one, two and three with special pigging technology, and between 8 and 19 January, Idroambiente installed the sixth TUBETEX liner with its reversion drum.
The round, woven, seamless TUBETEX liner, made of high-strength polyester yarn, was inserted into each supply pipe of the three units to a length of 157 m, and into each discharge pipe to a length of 113 m. The liner was then shaped by steam curing to a robust pipe with total length of 710 m.
The flexible basic structure of the fabric tube accommodates all contortions and the 90 degree elbows of the old pipe. As the final stage of the project, the seven bends of the supply lines and the five bends and two connections of the discharge pipes were provided with AMEX sealing before the pipe was put into operation.
Although the liner is firmly bonded to the old pipe with the flexible epoxy resin NordiPox TX to increase stability, it remains sufficiently elastic to compensate for movements and absorb impact on the pipes.
Looking ahead
Managing Director of Idroambiente Stefano Dini said “All in all, the West Burton project was considered a resounding success by all involved, particularly the client.
“With its coverage and smooth internal surface, corrosion and encrustation of the bonna pipe will be a thing of the past for at least the next 50 years,” said Mr Dini.