Prague: Trenchless Rehabilitation
of a Gas Pipe with the egeLiner®
Author and also consultant for Eastern Europe is Daniel Snajdr. This article was recently published in our egeNews.
Right in the centre of Prague, an old steel pipe was rehabilitated applying the egeLiner® technology. Owing to the tight space conditions, the high laying speed required and the focus on preventing any traffic disruption, there is no economically viable alternative to using this rehabilitation method for gas pipes. Consequently, the Prague utility company frequently resorts to the egeLiner®.
Rehabilitation of a historical gas pipe system in the center of Prague near the river bank.
- narrow time frame
- limited space conditions
- high traffic volume
Use of the egeLiner® RC on drums for trenchless feeding
|Client / Principal||Prager Gaswerke|
|Planning Office||Projektová Kancelár ANY|
|Realization||Relocation: Zepris s.r.o. / Ludwig Pfeiffer; Distributor: Gerex Liberec als Vertriebspartner|
|Construction Company||Zepris s.r.o. / Ludwig Pfeiffer|
Rehabilitation of Gas Pipe in Prag city center
Over the course of scheduled street rehabilitations and the reconstruction of the “Bridge of Legions” in the city centre on the banks of the Moldova in July and August 2020, the DN 500 steel pipe underwent rehabilitation. The insulation of the old steel pipe no longer fulfilled the current requirements. By rehabilitating the gas pipe, the Prague Gasworks ensure the future operational safety and security of supply for gas customers.
The Prague Gasworks have been one of the major energy suppliers in Czechia for a long time, with the history of the company dating back to 1847. Today, they reliably supply approximately 420,000 consumers all over Czechia with gas and electricity. Project planning was carried out by Mr. Arnost Polak from the Projektová Kancelář ANY engineering firm with his many years of experience.
Ensuring Operational Safety and Security of Supply
All in all, 404 meters of egeLiner® gas pipes made of PE 100-RC, DN 500, SDR 21 were used. The construction site was divided into 6 sectors measuring 30, 82, 51, 67, 81 and 93 meters. The pipe sections were manufactured to precisely match the sector lengths. They were delivered to the construction site wound onto drums and directly pulled into the old pipe by the installer on site
Easy to pull into old Pipe
Based on its particular advantages, the egeLiner®, a preformed pipe for close-fitlining, was the investor’s first choice, since this particular type of rehabilitation allows for continued utilization of the preexisting pipeline.
The approach represents a close-fit technology in accordance with EN ISO 11295. The egeLiner® PE 100-RC is resistant to stress cracking and has long been used in the gas industry in view of the special safety requirements involved and previous positive experience.
The result of the rehabilitation is a PE 100-RC pipe featuring the same pressure class as the surrounding steel pipe which provides additional protection of the inner PE pipe from potential mechanical damage.
The installation was carried out by Zepris s.r.o., a subsidiary of Ludwig Pfeiffer, a firm specializing on trenchless rehabilitation methods for drinking water, sewage and gas pipes. Together with this important egeplast partner in Czechia, many joint projects with large-diameter pipes and in special civil engineering have been performed successfully and according to professional standards by qualified staff. The egeLiner® system was supplied by Gerex Liberec as egeplast’s exclusive sales partner in Czechia.
Good Planning and Cooperation
Construction works began on 21 June 2020, with commissioning as early as on 29 August 2020. Installation in the heart of Prague during peak tourist season went as planned with only minimal interruptions of traffic – thanks to good planning and close cooperation between the utility, the supplier and the construction firm.
Branislav Ohrablo, site manager with Zepris s.r.o. with many years of experience in the area of close-fit-lining, preferably has come to use egeLiner® pipes in recent years. He commented: “We appreciate the reliable transportation and delivery of the egeLiner® pipes, them being wrapped in white foil, and the high-quality mounting of the pipes on the drums which allows for section-wise unwinding of the pipe from the drum. The material is of high quality and shows an ideal elastic resilience. Thank you very much for your excellent cooperation.”
Author contact details
Daniel Snajdr has been working for egeplast international GmbH since 2017. He advises our customers in the Eastern European region with a focus on the Czech Republic.