Trenchless installation

In inner-city areas and when passing underneath rivers, trenchless installation methods are today indispensable when it comes to replacing pressurised pipelines.

This application is coming into increasing use, since it is much more economical than open construction, which requires digging a trench, and significantly reduces the strain on the environment.

Due to their great strength, ductile cast iron pipes with therestrained BLSŪsocket jointare ideally suited for trenchless pipe laying

The press-pull process

In this process, the old pipe is pressed out of the ground by means of traction rods and a special traction and pressing head, while at the same time the new ductile cast iron pipe with BLSŪsocket jointand cement mortarcoating is drawn into the same channel

In this process, the nominal width of the pipe can also be increased. The press-pull process is outstanding for its great efficiency, speed, reliability and therefore economy.

This process has established itself in pipe laying as a trenchlessinstallation technique. Drilling technology has thereby undergone rapid development. The pipes are laid without the need for a trench through the use of a drilling system.

Instead of costly excavation, a pilot borehole is first calculated and drilled; obstacles and changes of direction are no problem, since the tip of the drill head is equipped with a radio-controlled probe. The course of the borehole can therefore be accurately monitored, checked and controlled.

The supply pipes are then laid without the need for a continuous trench. The only excavation required consists of a starting and finishing pit.

The controlled horizontal drilling technique has over the last 15 years established itself in the area of pipe laying and many other applications. The technique comes from the USA, where it was developed in the 1970’s in the field of deep drilling.

Burst lining

At the same time, the resulting space is enlarged, so that a pipe of the same size or even larger can be drawn in immediately.

Burst lining can be carried out using either the dynamic or the static process.

The rocket-plough process

The rocket-plough process can be used to install ductile cast iron pipes up to a nominal width of DN 300. The machinery used in the process consists essentially of a tractor machine with cable reel and a plough.

The most important component of the plough is the ploughshare. The plough is connected to the tractor vehicle by a steel cable. The pipe section is placed at the corresponding installation depth in a starting pit, which is excavated with a slope to allow the pipe to be drawn in, and then attached to the ploughshare.

Through the tractive force of the cable, the ploughshare then displaces the earth in the area of the pipe by means of the enlarging body. This creates a space into which the pipe is drawn immediately.

The plough process is particularly suitable for rural areas with a low population density, where long lengths of pipeline with only a few connections are required. This process has so far only been used for the installation of pressurised pipes.

Pipe relining

For this reason,pipe relining has become increasingly popular, since due to the lower volumes of water, smaller-diameter pipes can now be used, and this is exactly where long pipe relining comes into its own.

In this process, new ductile cast iron pipes are drawn or pushed into existing pipes which are no longer suitable for transporting water. Only a starting and finishing pit are required. The costs for civil engineering and road construction are correspondingly low, and the inconvenience to traffic and local residents are greatly reduced. The cavity between the old and new pipe can be filled in once the new pipe has been inserted.

 

please find attached our brochure "trenchless laying"