Rehabilitation with continuous pipe lining

Rehabilitation of pipelines using continuous pipe lining (freelining, sliplining) involves the use of polyethylene (HDPE) and polypropylene (PP) pipes. Such pipes are produced from materials which should comply with the EN 13244-1 standard. One can also use multilayer pipes and pipes with protective coating.

Once the damaged section of a pipeline is taken out of service a towline is inserted into it, with a directional roller at the end of the pipe.

Once a section of the host pipeline has been prepared as above a continuous pipe unwound from its spool, or one that is welded into appropriate length sections, depending on its diameter, is pulled into the host. One should remember not to exceed maximum pulling force, as this could damage the continuous pipe. To reduce friction slip agents can be used, like water, bentonite, slip film, etc. The pulling speed is controlled at the winch. Once the whole section has been pulled in, the section is checked for proper layout of the carrier pipe in the host, old sewer, and then the ends of the carrier are anchored.
When the new, carrier pipe has been anchored and sealed with the manhole or entry place in the insertion trench, the annular space between the old and new pipe can be filled with injection grout. The purpose of the injection grout is to stabilize the new pipe inside the rehabilitated sewer. If the old pipeline consists of connections attached using T-connections, before grouting they must be combined with the new pipe using pipe fittings to prevent uncontrolled grouting of the lateral drain.
Once the continuous pipe has been inserted the insertion trench can be backfilled and the surface can be repaved.

CCTV INSPECTION

Once the installation is finished and drains are opened a CCTV acceptance inspection is made and recorded on a DVD or another storage medium. At the same time an inspection report is prepared.

TESTS

In accordance with PN-EN ISO 11296-1 and PN-EN 13566-2.

Any defects are made good with the help of a camera-controlled robot and/or by patching with short sections of pipe liners. Extreme cases may require a trench and laying a new section of the pipeline.