Trenchless pulling in of a pipe

Trenchless pipeline construction

Environmentally friendly!

  • Prevents construction noise, does not affect traffic and causes no environmental damage
  • Reduces CO2 emissions
  • Route underneath obstacles
  • Replace pipelines of the same size or larger
  • High tensile strength
  • Quick and easy installation
  • Radii from 70 m

Over 30 years’ experience.

The development of trenchless pipe installation techniques is inextricably linked to the development of ductile cast-iron pipes and the associated joints and external protection solutions.

The potential of the restrained socket joint, which was developed as a replacement for the thrust block, was first recognised when the first trenchless installation techniques were being introduced. Since then, ductile cast-iron pipes from Duktus have been setting the benchmark in terms of reliability and cost-effectiveness .

In the 1970s, the first trenchless construction procedures sparked a rapidly developing revolution. More and more new procedures were introduced to the market – and customers were demanding ever-larger sizes and pipe lengths.

The joint

In most installation procedures, ductile cast-iron pipes are pulled into position. The only exception to this rule is the push-in pipe relining process. To pull the pipe into position, the joints in the pipe must be able to withstand tension. Generally, the joints should be of a positive locking design. Restrained socket joints can be recognised by the presence of a welding bead on the spigot end of the joint, as is the case with the BLS® joint.

The BLS® joint is recognised as the current benchmark for ductile cast-iron pipes; it offers maximum socket flexibility at the greatest tensile force, and is the easiest and fastest to assemble.

As well as enhancing the joints, the external coatings of the pipes also needed to be improved to meet the more challenging requirements of trenchless installation procedures. The result: the polymer-modified cement-mortar coating – known as CMC among professionals.

This duo of innovations – the BLS® joint and the CMC coating – laid the foundations for the future success of Duktus ductile cast-iron pipes in trenchless installations. In 2007, the company added another chapter to the ongoing Duktus success story, when it set the record for the largest ductile cast-iron pipe culvert ever to be installed in a horizontal directional drilling process in Europe, with the installation of a 500-m long DN 900 pipe in Valencia (Spain).


Product information