Sliplining is a process for rehabilitating deteriorated large-diametre gravity piping systems for the rehabilitating of pressure distribution and transmission lines.
Sliplining involves the insertion of a new pipe inside the defective host pipe, either in segments or as a continuous section of pipe.
PVC slipliners are designed to provide both structural support as well as an improved flow path to the deficient host pipe.
Segmental sliplining is the least disruptive type of rehabilitation for gravity sewer lines. PVC pipe, with smooth joints (both inside and outside), are assembled in segments at entry points along the length of the deteriorated host pipe, and inserted directly into the host pipe by either pulling or pushing. A section of the top half of the host pipe is often cut off to provide lead-in access. The outside diametre of the liner pipe is less than the inside diametre of the host pipe, which leaves an annular space between the two. In many cases, this annulus is filled with a grout after installation, particularly if the host pipe is in a high state of deterioration.
Grouting of the annular space provides additional support for the liner pipe, helps protect the liner pipe if the host pipe is in structural distress, and stops water infiltration through the host pipe annulus space. The loss in cross sectional area is often offset by the improved flow characteristics of the new PVC pipe.
Continuous sliplining with PVC pipe is more prevalent in the rehabilitation of potable water distribution and transmission pipelines.
In this process, the liner pipes are assembled in their entirety prior to being pulled into the deteriorated host pipe as a continuous pipeline.
As with gravity systems, grouting of the annulus is often employed to help stabilise the pipeline and increase the life expectancy of the line. When required, taps are made after the pullin of the new pipe into the host pipe.
Fusible PVC™ pipes are potentially the best solution for sliplining, where new PVC pipes are inserted into old pipe systems requiring rehabilitation.
Fusible PVC™ pipe systems provide the only method available in Australia to install a continuous, monolithic, seal-ring free PVC pipe, capable of use in numerous trenchless or conventional “open cut” installations. Applications for Fusible PVC Pipeline include pressure and non-pressure pipelines for drinking water, wastewater, electrical, industrial and telecommunications industries.
Fusible PVC™ is the most efficient trenchless pipe system for moving water, coupled with overall cost savings thanks to reduced installation costs due to lightweight pipes and reduced overall pipe dimensions.
The rehabilitation of existing sewer and water infrastructure is a challenge faced by all utilities. PVC has a proven track record of long-term performance and leads the water and sewer industry in market share. Utilities, design engineers and contractors are benefiting from the application of PVC pipe products to their pipeline rehabilitation and trenchless installation needs.