Spiral-Wound Liners Mean?
Spiral-wound liners are made by extruding polyvinyl chloride (PVC) in a factory and the continuous strip is coiled onto a large drum. The coil is then taken to the site where it is slowly uncoiled and installed in the host pipe by mechanical means.
It is a trenchless pipe rehabilitation technique that is used to line sewer pipes, stormwater drains, and culverts. The liner can be installed without stopping the flow and can be carried out from the manhole.
Trenchless rehabilitation of sub-surface pipelines is becoming popular because of its non-disruptive nature and ease of installation.
Trenchlesspedia Explains Spiral-Wound Liners
The safe installation practices for spiral-wound liners are specified in the American Standard of Testing and Materials (ASTM) F1741-18 and ASTM F1697-18. Liner pipes are installed into existing sewers and conduits by inserting a machine-made field-fabricated spiral-wound liner pipe.
The winding machine either remains stationary in the insertion pit or manhole or travels inside the host pipeline i.e. stationary installation or traveling installation.
In the stationery installation, for diameters upto 48" is expanded to fit into the existing pipe and alternately for diameters upto 108", the liner pipe is inserted as a fixed diameter pipe and not expanded. The annular space between the liner and host pipe is grouted.
in the traveling installation method, the liner pipe is installed in contact with the host pipes interior surface to form a close-fit liner and for non-circular pipelines, the liner is installed as a fixed diameter to form a non-close fit liner and the annular space is sealed with grout.