Trenchless rehabilitation with egeLiner® using the close-fit method

Under a residential campsite on Lake Balaton in Hungary, a DN 500 asbestos cement sewer pipe was trenchlessly rehabilitated using the close-fit method. The confined spaces and limited access points made the project particularly challenging. Through the use of the egeLiner® DN 500 in the close-fit method, the rehabilitation could be implemented on schedule and safely.

®AdobeStock_Geza Kurka

“Thanks to the proven close-fit method, the execution ran absolutely smoothly despite the difficult space situation. After reversion, the pipe fits tightly against the old pipe, thus enabling almost loss-free hydraulic performance.”

–

Daniel Snajdr

Challenge: Rehabilitation of a wastewater pipeline with limited access to the host pipe

Due to the location of the 398.3 m long pipeline to be rehabilitated beneath a campsite, conventional open-cut construction was out of the question. Several permanently installed mobile homes blocked potential access routes, meaning that only very few and, above all, small construction pits were feasible. Furthermore, Lake Balaton is a very popular tourist destination for visitors from all over Europe, which means that only a very limited time window is available for maintenance and rehabilitation work outside the season.

Direct pull-in of the egeLiner® DN 500 from the drum

Solution: Precise application of the trenchless close-fit method with minimal construction site requirements

The installation of the egeLiner®–pipes using the close-fit–method was carried out by the company Bonex, which specializes in trenchless installation. The pipe drums could only be positioned at two insertion pits. From there, five pre-deformed sections were pulled through several host pipe segments in succession and fitted against the inner wall of the host pipe through reversion.

The cramped conditions of this project highlighted the essential advantages of the egeLiner® rehabilitation process. The reduced cross-section of the folded liner, the ability to accommodate changes in direction using bends, and the delivery of entire rehabilitation sections on drums enabled the required pull-ins without the need for welding in the starting area of the construction pits.

Project description

Rehabilitation of a 398.3 m DN 500 AC transport pipeline in Hungary

Challenges

Pipeline beneath a built-up area; therefore minimal access and very limited space for construction pits

Solution

Pull-in of five pre-deformed egeLiner® sections via
two insertion pits; close-fit method

Installation

Trenchless; close-fit lining

Pipe system

egeLiner®, DN 500, PE 100 RC, SDR 21

Project participants

Client: DRV Zrt.
Planning: NODIG ’99 Kft.
Execution: BONEX Építőipari Kft.

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.