TPi January 2013

products & developments CIPP liner in power plants

already satisfies the strict criteria for the rehabilitation of sensitive infrastructure, eg for drinking water mains or cooling water pipes in power plants. With certain precautionary and preparatory measures, the method of installation of the pipe liner impregnated with special resins in the old pipe and thermal curing to form a new pipe is identical to the rehabilitation of subterraneous infrastructure in the public sphere. One of the first CIPP rehabilitation projects in power plants took place at West Burton in Nottinghamshire, UK, in January 2012. The plant is operated by EDF Energy, one of the UK’s largest energy companies, and supplies with its coal-fired and combined cycle gas turbine power station 1.5 million households of the region with electricity. To guarantee proper cooling of the three 430MW 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. While the sensitive surrounding allowed only a trenchless construction, the tight time frame and the main challenge the various 90° elbows of the bonna cooling pipe proved the Tubetex liner of SPR Europe to be the technological solution. The team of experts from Idroambiente and its German subcontractor Uniror started the cleaning of the six supply and discharge pipes with a diameter of 500mm in unit 1, 2 and 3 with special pigging technology. Idroambiente

For more than 20 years SPR (Sekisui Pipe Rehabilitation) Europe has been offering solutions for the renewal of decaying water or gas pipelines. Besides local authorities, electricity generators all over the world are now exploiting the advantages of trenchless pipe rehabilitation. SPR Europe is expanding the range of applications for its cured- in-place pipe lining method to include the rehabilitation of cooling water pipes in power plants. SPR Europe combines CIPP technology experts and construction companies under one roof. These maintain and renew the underground infrastructure of many local authorities and facilities worldwide through the rehabilitation of pressure conduits and sewers. The technologies are now proving themselves in another market: the rehabilitation of cooling water pipes in power plants. In a sensitive environment such as power plants of different types, the rehabilitation of pressure pipes and ducts are subject to strict quality controls. In Europe the CIPPmethod with NordiPipe™ and Tubetex™ pipe liners

The bonna cooling pipes before the lining works

Tubetex liner and AMEX seals cover the bonna pipe and protect against corrosion and encrustations

installed the six Tubetex liners with their 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 157m, and into each discharge pipe to a length of 113m, and shaped by steam curing to a robust pipe with total length of 710m. The flexible basic structure of the fabric tube accommodates all contortions and especially the 90° elbows of the old pipe. Finally the seven bends of the supply lines, five bends and two connections of the discharge pipes were provided with the special AMEX sealing before the pipe was put in operation. Although the liner is firmly bonded to the old pipe with the flexible epoxy resin NordiPox TX and increases stability, it remains sufficiently elastic to compensate for movements and absorb impact on the pipes. “All in all, the West Burton project was considered a resounding success by all those involved, particularly the client,” commented Stefano Dini, MD of Idroambiente Srl. “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.”

The EDF West Burton combined cycle gas turbine station

SPR Europe – Germany www.sekisuispr.com

Idroambiente’s reversion machine installing the Tubetex liner

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Tube Products International January 2013

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