TPi April 2008

OCTG water, gas &

Polyethylene pipes replace concrete in power station’s cooling water intake

cooling water into the power station through polyethylene pipelines instead of using pipes of less advanced materials. “ Normally, external weights are used to weigh down polyethylene pipes, but it isn’t practical when we’re talking about pipes with diameters of two to three metres that are going to be buried under the sea floor for safety reasons, ” commented Christian Vestman, project manager at KWH Pipe. “ By using non-hardening cement

Alstom has used polyethylene piping instead of concrete in a power station’s cooling water intake for the first time. The advantages of polyethylene piping are that it is easy to install on the sea floor and has a life expectancy of at least 50 years in salt water, compared to about 25 years for certain concrete pipes. The gas-powered combined cycle power plant was built in Fos-sur-Mer in southern France by CyCoFos, a power company that is a subsidiary of Gaz de France. The pipe used was KWH Pipe’s Weholite, one of the few polyethylene pipes that can be made in dimensions of more than two metres. In addition, the pipe has a hollow profile wall that can be filled with concrete to weigh it down. The piping is practically maintenance- free, since all joints are welded and polyethylene does not corrode in salt water. These qualities were factors behind the decision to bring the

Weholite, KWH Pipe’s patented profile wall piping system, ▲ ▲ is easy to install on the sea floor even when the diameter exceeds two metres

Stephane Delaplace, who works for Alstom’s subcontractor Entreprise Jean Negri & Fils, said that installation of the polyethylene piping was trouble-free: “ The job involved four parallel pipe sections of about 70 metres each. The piping was welded together in advance on land and transported as a whole to the installation location. It was then filled with water and sunk into the pre- dredged channels on the sea floor. Finally, the piping was covered with sand and rocks so the sea floor looked natural again. ” Constructing piping with short concrete pipe sections that are connected with sleeve couplings on the sea floor requires significantly more diving, which is an expensive operation. “ The actual underwater work took less than a day per pipeline, ” added Delaplace. “ There is also no risk of leakage in the piping, which is a risk with sleeve couplings. ” Weholite piping is easy to transport to the installation site, where it is sunk to the bottom by filling with water and then covered with sand and rocks.

mortar, the pipe retains its built-in flexibility, which means it can withstand different load situations on the sea floor better than rigid pipes. ”

Italian distributor Jannone Tubi Srl is a distributor of carbon, alloy, stainless, seamless and welded steel pipes for the petrochemical industry, gas and water distribution according to API, ASTM/ ASME and UNI-EN standards. The company is also

an official distributor of Tenaris/ Dalmine, and has been appointed as official supplier of important customers such as oil refineries and petrochemical plants.

The company’s sales departments are located in Milan and Bari. The company also has a large stock of 15,000t of pipes located in its Sannicandro di Bari (BA) warehouse, and 3,000t in its Mazzo di Rho (MI) warehouse, to promptly supply the north markets. The organisation also has two modern coating (ext/int) operating plants, one at Sannicandro di Bari (BA), and one in Cassano Spinola (AL). One of Jannone Tubi’s facilities, in Bari ▲ ▲

Jannone Tubi Srl – Italy info@jannonetubi.it www.jannonetubi.it

Oy KWH Pipe Ab – Finland marketing@kwhpipe.com www.kwhpipe.com

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Tube Products International April 2008

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