Laying techniques for plastic pipes made of PE
Plastic pipes can be laid in the ground using open and trenchless methods. We produce pipe systems that are suitable for both methods.
Open laying
Open-trench pipe installation includes installation methods in which a trench is excavated to place the pipe in the ground. The open laying methods for which our PE100 and PE100-RC pipes are suitable include: laying with and without a sand bed, and laying with double crushed chippings in accordance with DIN EN 1610.
Open laying with sand bed
For open laying in a sand bed, the excavated trench is prepared with sand and the pipe is embedded in the sand before the trench is backfilled. The sand protects the pipe from mechanical stress and external influences.
Offene Verlegung ohne Sandbett Open laying without sand bed
When laying without a sand bed, the pipes are laid directly in the excavated trench and the excavated material is reused as backfill. The excavated material often contains rocks and other coarse irregularities/foreign bodies. These can cause superficial damage such as scratches to the pipe. For this reason, only highly resistant pipes with high stress cracking resistance are suitable for this type of installation.
Trenchless laying
The trenchless installation of pipes and cables offers the opportunity to protect the environment, since virtually no construction work is done above ground. By avoiding costly surface disturbance, traffic disruption, dust and noise pollution are minimized. The steps required for trenchless installation are carried out effectively and in a comparatively environmentally friendly manner using targeted shaft and trench construction. Thanks to the minimal surface disturbance, the landscape and nature remain largely untouched.
This is accompanied by a significant reduction in costs, as the restoration of the construction environment is much less expensive. The time required is also much less than with open laying methods. Our PE100-RC pipes are suitable for the following trenchless installation methods Relining, plowing, milling and horizontal directional drilling.
Relining
Trenchless relining is the process of repairing pipelines through existing channels. Our PE100-RC pipes are used for this. These are connected to form a pipe string and then pulled into the existing pipe.
Execution:
Before the relining process begins, the existing pipe must be cleaned. Measurement values are then compared along the entire length of the pipeline to be replaced and it is ensured that this corresponds to the entire section of the new pipeline (calibrated cross section). The new pipeline is then drawn in through excavation pits using winches and pulling cables. Once it has been successfully pulled in, the space between the old and new pipe is filled with an embankment. This fixes the new pipeline and transfers external loads more evenly to it..
Horizontal flush drilling method
Horizontal directional drilling is particularly suitable for longitudinal installations, culverts and building undercrossings, as well as drainage and irrigation applications. Horizontal directional drilling can also be used to install cable in traffic control systems and for slope and embankment stabilization.
Execution:
Horizontal directional drilling uses a water jet to drill through an underground cavity. A drill head is first lowered into a pit to control the drilling. The drilling fluid, which may contain bentonite and various additives to stabilize the borehole, flows out of the drill head. The drilling fluid loosens the soil. Stones and other cuttings are removed from the borehole. The casing is then pulled in parallel with the retraction of the drill head.
Plowing
Pipe laying using the plow method is probably one of the most economical methods of pipe laying. Up to 5000 m of pipe can be laid in just one working day. In addition, no lowering of the groundwater table is necessary with the plow method, which makes it an environmentally friendly method.
Execution:
With the plowing method, a pipe is laid using a laying unit consisting of a laying plow with a plow blade: Laying plow with plough blade and laying box and a truck or crawler vehicle with an installed cable winch. The cable winch pulls the laying unit in the direction of the vehicle. As soon as the plough reaches the vehicle, the cable winch is moved into position on the next section. This process is repeated. At the starting point, the plow is brought to the desired laying depth. Depending on the diameter, several pipes can be pulled in at the same time. The weight of the plow automatically closes the soil behind it.
Milling
Plowing and milling are similar in some respects. However, the laying capacity is slightly lower with milling and fewer pipes can be laid per working day. It should be noted here that the pipes should have a particularly high resistance to stress cracking, as they are laid without a sand bed.
Execution:
A trench is cut into the ground using a motorized trencher. The pipe is laid in this trench. At the same time, the trench is backfilled, usually with the excavated material.
