Testing and Performance Evaluation of an Innovative Internal Pipe Sealing System for Wastewater Main Rehabilitation.

摘要

Many utilities are seeking emerging and innovative rehabilitation technologies to extend the service life of their infrastructure systems. This report describes the testing and performance evaluation of an internal pipe sealing system, which provides a permanent physical seal for the spot rehabilitation of cracks, leaks, corrosion, and other defects. The system tested was Pipe-Seal-Fix (TradeName) from Pipe-Robo-Tec USA. The Pipe-Seal-Fix (TradeName) system consists of a stainless steel sleeve and an ethylene propylene diene monomer (EPDM) rubber seal or gasket that span over a damaged spot in a sewer main. The sleeve and seal are installed together via a robotic closed circuit television (CCTV) camera and packer arrangement. The Pipe-Seal-Fix (TradeName) system is designed for use in storm and sanitary sewer pipe rehabilitation applications in diameter ranges of 8 to 24 inches (200 to 610 mm). Field demonstrations were attempted on a 10-inch sewer main in Santa Fe, Texas and an 8-inch sewer main in Baltimore, Maryland. Both locations had previously been lined with cured-in-place pipe (CIPP), but had significant defects allowing infiltration or exfiltration of the sewer flow. The system could not be installed at the Santa Fe, Texas location due to sagging and the ovality of the defective CIPP liner that prevented the system from reaching the repair site. The repair sleeve was successfully installed in Baltimore, Maryland. However, the repair was performed manually due to access issues that prevented the installation packer from moving through the pipe to the repair site. The post-lining inspection via CCTV showed the repaired section to be sealed, with no signs of exfiltration. The system was also tested via external hydraulic testing in the laboratory on three 8-inch steel pipes. The laboratory testing showed the seals were leak free for 2.5 hours above 15 pounds per square inch (psi), which is approximately twice the external hydraulic design pressure of 7.25 psi (0.5 bar). The material cost for the Baltimore, Maryland spot repair of an 8-inch sewer main was $756 and the installation occurred over approximately three hours. The project had a negligible carbon footprint as the equipment required for the installation was minimal. The technology shows promise as a low-cost and rapid trenchless repair approach. Access requirements should be assessed based upon site-specific conditions to ensure feasibility of the robotic-assisted installation, especially in previously lined pipes.