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Secure pipe systems – advantages of modern PE pipes
PE pipe systems have been used for the last 70 years. Experience has shown that proper pipe systems made of PE material are reliable and economical over many decades within the limits of their application fields provided they have been laid and mounted correctly. The selection of pipe materials and systems in civil engineering has extremely long-term consequences, more than anything else economically speaking.
The selection of pipe materials and systems in civil engineering has extremely long-term consequences, more than anything else economically speaking. Once installed, accessing these pipelines, which tend to be designed to outlast multiple generations, at a later point in time is hardly possible.
Trenchless techniques offer economic and ecological advantages
Trenchless techniques offer economic and ecological advantages
Final piping can only be accessed retrospectively in exceptional cases, because:
- it would imply damaging valuable sealed surfaces covering them.
- subsequent damages will result in tremendous costs.
- redirecting the traffic flow or blocking roads is hardly feasible considering today’s density of traffic.
In view of the cost ratios in civil engineering, alternative, trenchless installation methods have also come to be attractive from the economic viewpoint. Pipe prices rarely account for more than 15 percent; with 85 percent or more of the total costs related to civil engineering or the restoration of surfaces. Using trenchless installation methods opens significant cost saving potentials. In this context, the material-specific advantages of PE pipes (flexibility, low weight, great lengths, small construction pits etc.) reveal their full impact. A decisive factor which matters for the selection of materials is the installation method chosen and the associated risk of damage to the pipe systems opted for.
100-year useful life
The construction of underground infrastructures involves significant civil engineering works. Against this backdrop, every operator aims at being able to operate a new pipeline as long as possible without incurring any damages. If properly installed, pipes made of polyethylene provide a minimum useful life of 100 years. If, however, they get damaged during installation, which might be caused by damages or weakening of the pipe wall during the insertion of the pipe, these damages may significantly shorten the pipes’ otherwise lifespan. Since their standardised wall thickness is designed to exactly manage the existing operating pressure (plus an additional safety factor), every weakening results in a lower safety factor from the engineering point of view or, if the damage is significant, will even directly reduce the pressure resistance of the new pipeline and thus shorten its useful life.
Additive protective layer for damage-free installation
For open-trench installation techniques without sand bedding, point loads caused by rocks or shards pressing against the pipe wall are to be expected. For this installation method, using polyethylene pipes made of RC materials and featuring integrated protective layers as well as maximum resistance to slow crack growth is essential. This type of pipe design does not involve any protection from notching, regardless of whether the pipe wall is constructed with one, two or three layers! Trenchless installation methods notablystress a pipe during installation. The formation of grooves and notches in the pipes cannot be avoided when installing new pipes or rehabilitating old ones. Black box methods therefore require pipes equipped with an additional protection layer to ensure damage-free installation and operation of the pipeline.
Proof of non-damage
The technical codes of practice for trenchless installation methods stipulate a full documentation of all relevant processes involved in the construction measure. To achieve this goal, the recommendation stated in the applicable DVGW (German Association for Gas and Water Applications) regulations is to ensure a thorough incoming goods inspection of the pipeline as well as of pipeline accessories prior to open and trenchless installation. For trenchless installations in particular, it is recommended to perform a visual inspection of exposed parts of the newly installed pipeline sections before initiating a pressure test to check them for improper damages. The nonvisible parts of the pipeline (black box) remain unchecked in this process, thus not providing proof of a damage-free condition. Pipes which come equipped with integrated conductive strips, however, provide the opportunity to present a quality verification, thus closing this gap.
egeplast
SLM® DCS
Early detection of pipe damage and precise locating of leaks
The egeplast SLM® DCS pipe system (Damage Control System) – among other things – monitors the functionality of sewage pressure pipes during operation and is able to detect pipe damages early on.
Additional protective layer protects systematically new pipes during installation
| inner pipe made from PE 100-RC / Standard Dimension |
| electrically conductive strips for damage detection and functional monitoring |
| additional protective layer made from PEplus |
| Illustration: left: Undamaged pipe surface after peeling of the protection layer / right: Damaged surface increases risk during welding |
Using pipe systems with integrated conductive strips at the same time creates the prerequisites for continuous monitoring of the pipeline during operation, which offers some additional benefits.
Pipeline systems with integrated conductive strips enable:
1. the planner to document that he selected the appropriate pipes for the chosen installation method and that the contractual services performed by him are free of defects. Should a damage occur at a later time, he can point this fact out.
2. the building contractor to prove and document upon acceptance for reasons of precaution that the pipes were damage-free when he installed them. The final acceptance serves to confirm the perfect condition of the pipeline towards the customer. In theevent of any potential damage manifesting later, he can point this out.
3. the network operator to provide precautionary documentation proving that the pipeline structures were damage-free at the time of completion. It therefore stands to reason that network operators stipulate proof of damage-free installation upon acceptance by opting for pipes with conductive strips in their invitation to tender.
4. the network operator to also use the conductive strips to ensure continuous pipeline monitoring during operation and to obtain a complete documentation of its trouble-free operation. The intelligent early warning system ensures an immediate alarm even for very minor damages. Damages can be remedied quickly and at low cost, since fast and precise tracing to the meter help to minimize costs for civil engineering works.
Contact
Dr.-Ing. Thorsten Späth
Head of Product Management,
egeplast international GmbH
egeplast international GmbH
E-Mail: thorsten.spaeth@egeplast.de
Tel.: +49 2575 9710 266
