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Spiral Wound PVC (SPR), a patented technology from Sekisui of Japan, is an environmentally friendly process for the rehabilitation of both small and large diameter pipelines, often those with odd shapes, difficult access, and live flow conditions. SPR is the preferred large-diameter pipeline renewal method in Japan, with over 25 years of installation history.

SPR utilizes steel-reinforced, interlocking PVC profile strips that are grouted in place. The installation equipment utilizes standard access points without site excavation. SPR can also be installed in vertical applications such as wet wells, access shafts, and other large-diameter structures. SAK crews feed the SPR product from an above-ground spool into an SPR Winding Machine, which is located on one end of the damaged pipe. The winding machine, which conforms to the specific shape of the pipe, continually pulls and guides the interlocking SPR material into place. As the SPR material is fed through the machine, a smooth PVC pipe is formed within the existing pipe as the SPR material connects with itself, and the dual locking mechanism is permanently engaged.

After the unwound SPR material traverses the length of the pipe, bracing is installed to prepare for grouting. The annular space is then grouted with a special high-strength grout. After the grout sets, the frames are removed, and the pipe is ready for service. Installation of SPR is trenchless, allowing communities to avoid the high cost, hassle, and risk of open-trench construction in populated areas. For pipes from 48 to 148 inches in diameter, SPR is the smart solution to consider for rehabilitation needs where access is difficult, odd shapes and tight curves exist, corrosion resistance is needed, and work may need to be done in live flow conditions.


Aging sanitary and stormwater systems endanger the economic, public, and environmental well-being of cities nationwide. But for too many cash-strapped communities, the cost in time, money, and hassle to dig up and replace pipelines can outweigh the benefits. With our proprietary SPR technology from industry leader Sekisui of Japan, SAK has saved communities millions of dollars by restoring pipelines instead of replacing it.

  • Adaptable: Curves and odd shapes are no match for SPR.  Tight curves up to Radius = 5 X Diameter are now possible. Shapes from circular, to square, to rectangular, to horseshoe, and even arches are practical applications for SPR.

  • Structural: SPR is a customized structural solution to fix aging pipelines and is designed for installation in live flow conditions. It can be engineered to correct hydraulic anomalies as well as restore the slope of the original pipe. SPR’s materials have been tested in accordance with industry standards and approved to meet ASTM F1697-07 and ASTM F1741-07 specifications.

  • Accessible: SPR’s design allows end-to-end installation through existing access and hard-to-reach locations with minimal disruption to existing infrastructure.

  • Community-Friendly: Safer and faster than traditional open-cut methods, SPR installation requires little, if any, excavation, minimizing the need for traffic detours or service interruptions. It’s also well suited to busy traffic areas where the construction site cannot remain overnight.

  • Affordable: Costing 20 to 40 percent less upfront than open trench rehabilitation, SPR also saves money in the long run by preventing pipeline breaks, reducing treatment and pumping costs, and minimizing the need for future intervention or maintenance.


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