Quelle: PRS Rohrsanierung GmbH
Lesedauer: Berechne...
Using close-fit with pre-deformed PE pipes is a highly efficient and economic solution for rehabilitating old drinking water pipes. Thanks to the trenchless installation involved as well as long durability and improved hydraulic properties, it provides a future-proof alternative to replacing old pipes and thus contributes significantly to ensuring sustainability of supply.
Maintainance and replacement of existing drinking water pipelines pose major challenges for many utility companies. In addition to costs, environmental factors, operational interruptions, compliance with hygiene standards and structural limitations play an important role. The close-fit approach to rehabilitating legacy pipelines using pre-deformed polyethylene pipes (PE pipes) is an innovative and sustainable method. It provides for a cost-efficient trenchless rehabilitation and greatly prolongs the useful life of the pipe network, since the inserted new pipe does not merely represent a repair measure, but equals the installation of a new pipe with an expected useful life of more than 100 years.
How the close-fit method works
The close-fit method involves pulling a predeformed folded PE pipe with a reduced diameter into the existing pipeline. Subsequently, the original shape of the PE pipe is restored by means of vapour pressure, which causes the new pipe to fit snugly to the inner wall of the old pipe (Close-Fit). This process consists of several steps:
1. Preparation of the existing pipeline:
- Cleansing of the old drinking water pipe to remove deposits and corrosion residues.
- Inspection of the old pipe to assess its structural integrity.
2. Insertion of the pre-deformed PE pipe:
- At the factory, the new PE pipe is initially manufactured round and then undergoes pre-deformation using a special production process, thus reducing its cross section.
- Its reduced size ensures that there is little resistance when pulling it into the old pipe over larger distances.
3. Extension of the pipe using vapour pressure or hot water:
- Once inserted, the pipe’s original round shape is restored by means of controlled heating with vapour or hot water.
- As a result, the pipe will fit snugly to the inner wall of the old pipe, thus creating a structural, tight and self-supporting inner lining.
4. Cooling and pressure test:
- Once fully expanded, the new pipe is left to cool. Afterwards, it will be seamless and operational and thus equals a new pipe.
- Finally, a pressure test is performed to ensure that all couplings and connections are leak-tight.
The close-fit method is particularly suitable for:
- Drinking water and gas pipelines in urban and industrial areas
- Sewage pipes with critical infrastructure within which conventional rehabilitation measures would be problematic
- Areas with a high volume of traffic, for which open-trench construction would result in significant disturbances
The execution of close-fit rehabilitation measures of this kind requires a company specializing in this field. Please find a brief introduction of two partners of our company providing these services below:
Diringer und Scheidel
A long-established company, DIRINGER & SCHEIDEL DRUCKROHRTECHNIK provides innovative solutions for trenchless rehabilitation of pressure pipes using the full gamut of standard certified rehabilitation measures, including close-fit-lining.
In this context, high-quality products made by egeplast have become a trusted source. Thanks to its decades of continuously evolved knowledge, DIRINGER & SCHEIDEL DRUCKROHRTECHNIK is also able to offer customized solutions from a single source. This fact ensures high cost-effectiveness and shortened construction periods while at the same time going easy on ressources.
PRS
PRS Rohrsanierung GmbH is a member of the PREUSS Group. For more than 20 years, utility and industrial companies have relied on the proven expertise and capacity of the PREUSS Group in the context of building, modernizing and operating infrastructure and systems. With close-fit lining, PRS offers an optimal relining renovation method which specifically allows for topquality sustainable and environmentally friendly rehabilitation of pressure pipelines. Water means life — drinking water pipelines require particular diligence. Ensuring the safety of gas pipelines, too, takes experts. You find both at PRS! PRS Rohrsanierung: A rehabilitation team you can always rely on.
Benefits of the close-fit method
Trenchless rehabilitation
No costly and timeconsuming road- or earth works, which helps to minimize traffic obstruction and surface disturbance.
Optimised hydraulics
The smooth inner surface of the PE pipe leads to reducing flow resistance while at the same time improving flow capacity and minimizing deposits.
Little operational interruption
Fast installation in many cases allows for keeping the drinking water supply intact or ensures short-term interruptions only.
High longevity
PE pipes are corrosion resistant and resistant against chemicals and boast an operating life of more than 100 years.
Sustainability
This method serves to save ressources, to reduce the CO2 footpring and to extend the useful life of pre-existing infrastructure without extensive new construction measures. The pipe material is 100% recyclable.
egeplast
egeLiner®
| The pre-deformed egeLiner® is wound onto steel drums – matched to the required length of pipe to be rehabilitated. This way, the cross section can be reduced by up to 40 percent, meaning that large overall lengths can be supplied to the construction site. |
| As a matter of principle, the folded egeLiner® pipe attempts to balance the tensions which have been frozen in the pipe wall and to transform the pipe in a way which causes it to once again take on its rounded original shape, referred to as a reversion process which enables it to return to its original shape (“memory effect”). This is the property which makes the close-fit method so efficient and ensures that the egeLiner® fits tightly to the inner wall of the old pipe following successful installation and can be integrated fully into the existing pipe network. |
before and after the expansion process
Dr.-Ing. Thorsten Späth
Head of Product Management, egeplast international GmbH
E-Mail: thorsten.spaeth@egeplast.de
Tel.: +49 2575 9710 266
