TPi September 2014

products & developments

bearing capacity of the loamy soil, for weight reasons the liner had to be divided into two lengths of 164m. The impregnation process took place on a road near the construction site. Long distance was needed for laying out the liner while being impregnated by a mobile impregnation setup and directly wound onto a transport spool. The main and calibration hoses were impregnated with the specially designed Nordipox D epoxy resin at around 4°C. After pipe cleaning, the main hose was gradually drawn into one of the two 164m pipe sections by a 20-tonne capacity winch. The calibration hose was then inverted with low pressure and a speed of 3 to 5m/min by means of a pressure drum to position the main hose in the old pipe. The hoses were steam cured at a laminate temperature of 70°C and a new stand-alone pipe was created within a period of two hours. The insulating PE outer coating of the main hose allowed a reduced curing time, despite the challenging construction site conditions and the high water level. The rehabilitation process was concluded after sealing the four ends of the two 164m liner sections within two weeks. Following a pressure test,

layers, selected according to internal pressure and diameter. Its durable PE outer coating protects the liner from external influences during installation and operation. The calibration hose, a needle-felt liner with PE coating, raises the main hose into position within the old pipe and provides a smooth surface with increased hydraulic performance compared to the old host pipe. Both hoses are impregnated with Nordipox D, a two-component epoxy resin, to receive a homogeneous material combination as well as a consistent liner structure in the cured state. The pull-in version allows an accurate calculation of the resin material and a consistent resin distribution. Its particular material composition of glass- fibre, needle-felt, resin and PE coating makes it a fully structural liner. It can therefore be called a ‘stand-alone pipe’ for the purposes of DIN EN ISO 11298 Class A. Three construction pits provided access to the 328m-long pipe section at a depth of 3m beneath a field alongside a main road. The installation length of 328m would normally have been no problem. However, due to the poor

Smooth inner surface of the liner with increased hydraulic performance

the pilot project for the Nordipipe pull- in liner for a 920mm diameter pipe was successfully completed. The pipe was put back into 24-hour, seven-day operation to supply the city of Shumen safely with drinking water.

Sekisui SPR Group – Germany www.sekisuispr.com

Arrival of the calibration hose in the intermediate pit

Aluminium tube in China

Aluminium precision tube made in China Cold drawn seamlesss tube Cold drawn coil tube For Seawater desalination device Power generation heat exchanger Industrial refrigerant system

WUXI HATAL ALUMINIUM CO., LTD No. 72, Zhouxin (E) Road, Binhu District, Wuxi, Jiangsu Province, 214121, China

Tel: +86 510 85069506 Fax: +86 510 85061423 E-mail: sales@hatal.com.cn

www.hatal.com.cn

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September 2014 Tube Products International