The close-fit method with pre-deformed PE pipes represents a highly efficient and economical solution for rehabilitating old pipelines. It enables cost-efficient, trenchless renewal and significantly extends the service life of the pipe network. The inserted pipe does not merely serve as a repair, but is equivalent to a new installation – with an expected service life of over 100 years. With the expansion of the product portfolio in dimensions from 200 to 300 mm to include the SDR 13.6 pipe series, operating pressures of up to 12.5 bar can now be achieved, and the insertion of particularly long pipeline sections without a single pipe connection is made possible – which further increases operational safety and significantly reduces installation effort.
Rehabilitation using the close-fit method with egeLiner® conserves resources and saves operating materials.
Close-Fit Technology for Sustainable Pipe Rehabilitation
At the egeplast plant, the pipe is first produced in a round shape, then cooled and deformed into a C-shape at a precisely defined temperature. This temperature is chosen so that the so-called “memory effect” of the originally round pipe is frozen. As a result, after insertion into the pipeline to be rehabilitated, the cross-sectionally reduced pipe remembers its original shape during heating with hot steam. It expands independently under slight steam pressure and fits snugly against the inner wall of the existing pipeline as a round pipe using the close-fit method.
The operating pressures and static loads are fully absorbed by the new pipe for a service life of up to 100 years – regardless of the surrounding old pipe. Fittings, components for changes in direction, and longitudinal connections are made using PE fittings, which are directly connected to the PE pipe with the same operational safety and durability.
Rehabilitation using the close-fit method with egeLiner® conserves resources and saves operating materials. At the same time, CO2 emissions are significantly reduced, as construction site expenses are minimized, and both excavation and the disposal of building materials are eliminated.
Higher Operating Pressures Thanks to
Expanded Product Portfolio
Previously, the operating pressures of rehabilitated drinking water pipelines were limited to 10 bar. With the expansion of the product portfolio in dimensions from 200 to 300 mm to include the SDR 13.6 pipe series, operating pressures of up to 12.5 bar can now be achieved.
The C-shaped pre-deformed pipes are available as long single lengths of up to 460 m on drums. This enables the insertion of particularly long pipeline sections without a single pipe connection, which further increases operational safety and significantly reduces installation effort.
egeplast
egeLiner®
The pre-shaped egeLiner® is wound onto steel drums, tailored to the length of the section being renovated. This achieves a cross-sectional reduction of up to 40 percent, allowing long construction lengths to be delivered to the site.
Fundamentally, the folded egeLiner® pipe strives to equalize the stresses frozen in its wall and transform back into its round original shape — this is referred to as the reversion process, which causes the return to the original form (“memory effect”). This property makes the close-fit method highly efficient and ensures that, after successful Installation, the egeLiner® adheres closely to the inner wall of the old pipe and can be fully integrated into the existing pipeline network without restriction.
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