Situated on the side of a busy highway, engineers set up what some might call the ultimate remote-controlled tank. Carefully, with only a few inches to spare, a technician lowers what looks like a small tank into a 30-inch water main. The device is a robot called PureRobotics® and it’s about to give Louisville Water a glimpse into this critical piece of infrastructure.
The device includes tools that check the strength of the water main which is made of pre-stressed concrete cylinder pipe. Once PureRobotics® is in the water main, a technician uses a remote-control to steer it through the pipe. A high-definition camera on PureRobotics® makes sure the device doesn’t run into the side of the pipe and also records video. Louisville Water has a partnership with Pure Technologies which owns the inspection equipment. Louisville Water engineers work with Pure to map the route and prepare the water main for the inspection.
In this inspection, water is emptied from the section of main the robotics will move through. Valves help engineers control the flow of the water so the main is empty for the inspection and customers still have water service. Once the inspection is complete, the pipe is cleaned and then filled with water.
Once the inspection is complete, technicians will evaluate the data and provide Louisville Water information on sections of pipe that need to be examined for potential repairs. This project costs $1.7 million and is part of Louisville Water’s 2015 capital budget.
This inspection is part of a new focus on large water mains – those 20-inches in diameter and larger. Louisville Water began operations in October, 1860 with 26 miles of pipe. Today, the company maintains over 4,170 miles of pipe. Approximately 200 miles of the water main is transmission mains, pipes larger than 20 inches in diameter. The remainder is distribution mains that are 16 inches and smaller in diameter.
Louisville Water began a defined program in the mid-1980s to identify and repair water mains starting with pipe that was 12-inches in diameter and smaller (distribution mains.) The technology to inspect the larger mains is relatively new. In 2009, Louisville Water began a proactive approach to focus on pipes larger than 24-inches in diameter. Working with Pure Technologies, we have used a variety of tools that can inspect the pipes while they are filled with water and in service and others like PureRobotics® that require emptying a small section of the pipe.
The goal of the program is to minimize the number of water main breaks, especially those on larger pipes which can create extensive damage and impact water service for thousands of customers.
Louisville Water plans another inspection of a transmission main in late summer, this time using “PipeDiver,” a robotic tool that moves through a water main that is filled with water and in service.