Trenchless Rehabilitation with egeLiner® using the Close-Fit Method

Beneath an active campsite at Lake Balaton in Hungary, a DN 500 asbestos cement sewer pipeline was trenchlessly rehabilitated using the Close-Fit method. The confined space and limited access points made the project particularly challenging. By using 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 proceeded absolutely smoothly despite the challenging space constraints. After reversion, the pipe fits snugly against the old pipe, thus enabling almost loss-free hydraulic performance."

–

Daniel Snajdr

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

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

Direct insertion of the egeLiner® DN 500 from the drum

Solution: Precise Application of the Trenchless Close-Fit Method with Minimal Construction Area Requirements

The installation of the egeLiner®‑pipes using the Close-Fit‑method was carried out by Bonex, a company specializing in trenchless installation. The pipe drums could only be positioned at two insertion pits. From there, five pre-deformed sections were successively pulled through several old pipe segments and, by reversion, laid against the inner wall of the old pipe. The confined space conditions in this project highlighted the significant advantages of the egeLiner® rehabilitation method. The reduced cross-section of the folded Inliner, the ability to make directional changes using bends, and the delivery of entire rehabilitation sections on drums enabled the necessary insertions without requiring welding in the starting area of the excavation pits.

Project Description

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

Challenges

Pipeline under developed area; therefore minimal access and very limited space for excavation pits

Solution

Insertion 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.