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Cement Mortar Lining – an economic alternative

The cement mortar lining of drinking water lines according to DVGW worksheet W 343 executed by specialised companies and certified pursuant to R4 is an economic procedure for the restoration of pipes made of different materials in water distributing networks, the operational reliability of which has been impaired by incrustation and corrosion. The most modern machine technology allows the lining of pipelines with nominal widths from 80 mm up to 3,000 mm made of steel, grey cast iron, ductile cast iron and other materials.

After the shut-down and the cleaning of the pipe section to be rehabilitated, to the lining material is cast onto the pipe wall by means of a fast rotating centrifugal head. In large pipes from DN 600 the lining can take place with electrically operated centrifugal machines self-driving on pneumatic tyres.

In small pipes from DN 80 to DN600 the lining is usually applied by means of motors operating with compressed air. The cement mortar is pumped from a mixing vessel via a mortar tube into the centrifugal head.

Radially arranged and comb- shaped outside metal sheets allow a uniform distribution of the mortar. A constant tension velocity provides a uniform and optimal layer thickness. The setting of the mortar takes about 24 to 26 hours. Then the pipe can be filled and taken into operation.