Definition - What does Close-Fit Sliplining mean?
Close fit sliplining forms a close fit within the host pipe. This is achieved by temporarily deforming the lining and expanding it to its original size after insertion.
This forms a close fit on the host pipe and eliminates the need for grouting. It is a type of trenchless rehabilitation technique that can be carried out from entry and exit points, which are essentially manholes at the pipe ends.
Trenchlesspedia explains Close-Fit Sliplining
A thermoplastic tube that has been temporarily deformed to allow it to gain entry into the host pipe is inserted using a winch and cable. Thermoplastic materials can change shape when tension or compression forces are applied to the material. When the external force is removed, the material reverts back to its original shape.
When the thermoplastic pipe is correctly placed within the host pipe, the tension holding the pipe in the deformed shape is removed. Internal pressure is applied to help the pipe regain its original shape that forms a close fit into the host pipe.
This method is advantageous because the original pipe diameter is minimally affected, no grouting is required and long lengths of lining can be installed. However; this method works best for circular pipe cross-sections and cannot accommodate tight radius bends.