SewerVUE Technology Corp. has released a robot-mounted, in-pipe inspection system that incorporates CCTV with ground-penetrating radar (GPR).
The SewerVUE Surveyor system accurately measures pipe wall thickness, pipe wall composition defects and rebar cover, while also locating cracks in the pipe wall and detecting voids and cavities outside pipelines, enabling prevention of potentially catastrophic sinkholes.
Primary applications include mapping sewers, water mains and tunnels for regular inspection, quality control and preventative maintenance. “SewerVUE can also be used for testing the condition and thickness of liners, or for installation or quality control of concrete or vitrified clay pipes,” says company president Csaba Ékes.
The company developed the system in response to inquiries from engineering firms wanting a way to detect voids behind sewer pipes and measure pipe wall thickness in large-diameter concrete pipes without confined space entry.
While CCTV provides visual information and laser and sonar profiling provide geometric data that can indirectly indicate pipe corrosion or loss, GPR enables users to “see through” concrete pipes. “Regular inspections with this technology enable the location of voids caused by damaged pipes before they develop into sinkholes,” Ékes says.
Rebar cover is another critical measurement as it helps engineers estimate the remaining life of concrete pipes. When hydrogen sulfide erodes concrete at the crown of the pipe to the point where the rebar becomes exposed, the rebar becomes vulnerable to corrosion, and the pipe is susceptible to collapse, Ékes notes.
The SewerVUE system deploys GPR equipment mounted on tracks and is equipped with two high-frequency antennae. The current system can be adjusted to survey 18- to 30-inch pipes, and a larger version for 36- to 72-inch pipes is planned for 2011. The GPR antennae can be rotated between nine o’clock and three o’clock positions.
Radar data collection is continuous on two channels in both in and out directions, allowing a continuous reading. CCTV data is recorded simultaneously and is correlated with the GPR data collection. The system is equipped with two CCTV cameras (front and back). The standard tether length is 1,500 feet but can be upgraded to fiber optic cables with a maximum length of 6,000 feet. For information: 888/973-9378; www.sewervue.com.
