Spiral wound lining is a trenchless rehabilitation method used to restore sewers, storm drains and culverts between 6” – 200”.
Machinery is utilized to construct fully structural PVC liners directly inside deteriorated pipelines. Like most trenchless technologies, it costs considerably less than dig-and-replace in typical pipe rehabilitation scenarios.
However, each lining methodology offers unique cost-saving efficiencies.
Convenient Live Flow Pipe Lining
Determining how to handle the flow levels during the lining portion is a common factor for pipe rehabilitation. Many popular methods of renewal even require a dry pipe for installation. Because of this, flow diversion plans and temporary bypass pumping are critical components within trenchless pipe rehabilitation planning.
Spiral wound technology, however, is capable of lining within live flow, negating the need for bypass or diversion. This is due to the Spiral Wound process being completely mechanical and pipe-grade PVC acting as the sole lining material. The winding equipment and PVC material are not affected by existing flows during lining.
Spiral wound lining typically works inside pipes with up to 30% low-velocity flow because of one main concern: higher levels of flow puts worker safety at risk as the smooth nature of PVC liners may become very slippery.
During extremely high flow days when work is not permitted, some work materials and equipment can remain inside the pipeline. Plus, any natural debris within the flow doesn't damage the lining process. The mechanical equipment powers through flows, continuously locking and forming the PVC liner.
Why this can save you money
For certain trenchless lining methods, flows are plugged or pumped around the area of rehabilitation. This can become costly for contractors working the job. Temporary bypass pumping can fall between 15% - 25% (or higher) of the total bid, especially when lining larger diameter pipes. Spiral wound lessens, and in many cases eliminates, costs associated with flow management.
Efficient Above-Ground & Construction Footprint
Spiral wound is a minimalist technology; the main work, machinery and equipment are located within the pipe. The components sitting above ground depend on the scope of the project. A PVC spool loaded onto a truck or multiple spools accompanied by a forklift is the typical setup. The number of spools varies with the size of the project.
In order to power the winding machine and unspool the PVC, a hydraulic unit is also required. But these are generally small and easy to maneuver. Since the machinery is assembled inside the pipe, the only material passing through the access during installation is a strip of PVC, measuring between 4" - 5" wide. Because of this, spiral wound liners can reach almost all conventional access chambers with 100 percent trenchless integrity.
Not only is there minimal equipment impact, but Spiral wound liners permits less workers needed to be present onsite. The typical crew numbers around 5 to 6 for a pipe rehab job, with larger/multiple crews for bigger projects. Because heavy-duty machinery and equipment isn't needed, this allows for a lean, efficient installation team.
Why this can save you money
Certain trenchless lining methods need a larger access area to enter the pipe and require pit excavation near the pipe entrance. Excavation and larger crew sizes increases construction costs. Excavation and backfill alone can reach 100's of thousands of dollars for certain trenchless methods.
They also amplify the above ground impact which may disrupt traffic and the community. The great thing about Spiral wound liners, is that they solve costly excavation methods, plus they effectively reduce crew sizes and help to keep traffic control costs low.
A Time-Saving Installation Process
Because of its innate properties as a lining technology, spiral wound provides contractor's with a time-saving tool. The mechanical nature of PVC lining provides many of these efficiencies. And because there are no chemicals present, cure times aren't even necessary. A PVC liner is installed, sealed at the ends and essentially ready for service.
Many steps such as set up, tear down and maintenance can all be skipped because lining in live flow additionally provides the benefit of avoiding the time associated with bypass pumping operations.
Additionally, the ability to install within existing access chambers also eliminates time spent digging and backfilling pits. The winding process also allows for starting and stopping. This feature alone helps avoid costly errors and provides flexibility on the construction site.
Spiral wound's lining speed per linear foot is a major contributing factor to cost efficiency. Smaller diameter projects see upwards of 600 LF - 700 LF of renewed pipe in a single workday. Plus, SPR™EX and SPR™TF are grout-less, tight-fitting trenchless rehabilitation solutions. Pipe lining occurs in close contact with the host pipe with no additional steps to fill the gap between the liner and pipe wall.
The pipeline is fully rehabilitated the moment all lining, end-sealing and lateral reinstatement (when applicable) are complete.
Why this can save you money
With fewer steps to plan for, there's less time needed and much less money used on the pipe rehab project. Spiral wound takes away several variables typically associated with trenchless pipe lining.
This benefits municipalities and contractors a game-changing, cost-effective tool for successful pipe rehabilitation.