Electro Scan Inc. recently announced the results from its Fifth Annual Survey of Cured-In-Place Pipe (CIPP) with findings showing over 5,000 leaks for the twelvemonths ending December 31, 2020. The annual survey consolidated results from utilities, licensed contractors, and Electro Scan Services, worldwide. In 2020, 33% of CIPP showed leakage rates of 20 gal/min (75 l/min) or more, with only 15% achieving zero leakage. This is the lowest level since the beginning of this annual survey. During the year, a 52 in (1,320 mm) diameter CIPP liner was evaluated finding leaks missed by Closed-Circuit Television (CCTV) cameras. Utilities purchasing Electro Scan in 2020, typically added to existing CCTV trucks, with a 60% growth.
CIPP Assessment projects
Since 2014, Electro Scan Inc. has conducted over 1,500 CIPP assessment projects covering 40 suppliers. CIPP is a widely used method of pipe rehabilitation using a variety of composite materials to reline existing pipes, without digging. Temporarily covering a homeowner’s connection, robotic cutters are required to re-open each service, often resulting in new leaks. As a result (according to Electro Scan), lined pipes often leak more after rehabilitation, than before rehabilitation, a situation not discovered using visual inspection.
Machine intelligent solution
Electro Scan represents a machine-intelligent in-pipe leak detection solution that provides pinpoint locations of leaks with 10 mm (⅜ in) accuracy. Results are automatically provided in gallons per minute or litres per second. The continued use of CCTV to accept CIPP as watertight and reduced quality control during the COVID-19 pandemic, may have adversely contributed to the 2020 results. In 2020, Electro Scan Inc. was commissioned by a leading utility to compare 50-year-old Vitrified Clay Pipe (VCP), 10-year-old CIPP, and recently installed CIPP sites. Recently installed CIPP represented 35% of total length contributing 50% of the infiltration, with 80% of reconnections substantially leaking compared to only 2% which was found using CCTV. Today, an increasing number of CIPP suppliers recommend owners use ASTM F2550 (The US Standard Practice for Locating Leaks in Sewer Pipes by Measuring the Variation of Electric Current Flow Through the Pipe Wall) for liner acceptance to differentiate their liners from other trenchless solutions.
