A spatial map of the pipeline depicts elevation changes as well as notable features of interest encountered during an inspection.
To many history buffs, “the prettiest ornamental water tower and pumping station” in the U.S. belongs to Louisville Water. In 1860, the water company, which today provides water to more than 850,000 people in Louisville, Kentucky, and surrounding communities, built its first water tower and pumping station in the form of a Greek temple complex.
Today, the Louisville Water Tower and Pumping Station house the WaterWorks Museum, and Louisville Water continues to make history using modern technology to assess its extensive water network.
By prioritizing the risk levels associated with their transmission main system, Louisville Water has created an ongoing inspection program to keep a watchful eye on the health of their pipelines.
In May 2015, the PureRobotics pipeline inspections system from Pure Technologies was deployed on the Cross County Header, Ray Lane Easement pipeline, and Bardstown Road pipelines. For Louisville Water, PureRobotics used CCTV to provide a comprehensive high-definition visual inspection. The robotic crawler was also outfitted with specialized tools to conduct an electromagnetic assessment on the condition of the pipeline and inertial measurement unit (IMU) for a GIS component.
The IMU deployed with PureRobotics uses a series of fiber optic gyroscopes (FOGs) and accelerometers to track depth, lateral and horizontal movements from a known GPS reference point. The output is a GIS spatial map of the pipeline which depicts elevation changes as well as notable features of interest encountered during the inspection.
PureEM electromagnetic assessment detects anomalous regions in the pipe cylinder and prestressed wires. This data is correlated with odometer readings from the PureRobotics umbilical tether as well as HD-recorded CCTV and IMU to attempt to locate areas of distress in the pipeline.
Due to its mobility, PureRobotics is ideal for multiple isolated inspection runs where a quick setup and breakdown can improve efficiency. The transporter can be deployed from a number of access styles including valves, open flange, and open pipe. In the case of the Louisville Water inspection, the PureRobotics system was inserted into the pipeline via newly installed vertical gate valves and existing boiler-plate-style hatches. Inspection lengths varied in length from 70 feet to beyond 2,000 feet.
Results gave Louisville Water the confidence to prioritize its rehabilitation program
High definition CCTV inspection results showed a number of longitudinal cracks consistent with overloading. These types of mortar cracks may eventually lead to corrosion of the steel cylinder or prestressing wire and eventually a failure of the pipe.
One pipe section in the Ray Lane Easement pipeline was found to display anomalous electromagnetic signals showing a significant number of broken prestressing wire wrap breaks as well as cylinder wall loss. This was correlated with visual data, showing spalling and exposed steel at the invert of the pipe.
Visual assessment also showed a number of pipe sections with spalling. Electromagnetic assessment also found 11 pipes with anomalous signals not consistent with wire breaks. Investigation performed on one of these anomalous pipes showed a non-standard metal sleeve used in manufacturing. From this information, it was determined that the remaining 10 anomalous pipes could be left in service.
As one of the first utilities to deploy the third-generation PureRobotics platform, Louisville Water now has defensible data to move forward with its ongoing rehabilitation program. For this historic water utility, modern technology really can help.
One of the 11 anomalous pipes excavated.