What is Slip-lining?

Slip-lining is a trenchless method of rehabilitating an existing pipeline, similar to all the trenchless methods, a launch and reception pit is needed. However, the existing pipeline is not broken and displaced and remains in position. Slip-lining rehabilitates the existing pipeline by installing an HDPE sleeve into the existing pipeline.

Where can it be used?

Slip-lining can be used on any pipeline that needs to be rehabilitated and can be used in both high-pressure and low-pressure applications. While this ensures that the existing pipeline is rehabilitated it reduces the overall capacity of the existing pipeline and thus is rarely a viable method unless HDD or Pipe Cracking/Pipe Bursting is an impossibility.

Our Capabilities

Generally we use a hydraulic winch for the Slip-lining process however we are able to use our HDD rigs and pipe cracking rig to slip-line, thus an existing pipeline with a ID greater that 110mm up to and including a 1000mm pipeline can be rehabilitated by means of Slip-lining.

A quick run-through of the Sliplinning Process.

The process starts with Group 33 Engineering obtaining the existing pipelines CCTV footage, we then ensure that the pipeline is free from any defects such as collapses or ovalities that would cause the product pipeline to be stuck during the Slip-lining process.

The line is cleaned by means of mechanical cleaning where a squeegee of the same OD as the existing pipeline ID is pulled through the existing pipeline, once we are satisfied that the line is clean and there are no ovalities we pull the winch cable through to the launch pit where it is connected to a bullnose with the new product pipe attached, the new product pipe is then continuously pulled until it reaches the reception pit.

Should we need to use our HDD rig or Pipe Cracking rig, the process remains the same, only the pulling mechanism changes.