For utilities with large-diameter networks, waiting for failures to occur before repairing or replacing highly critical mains is not an option.
With a large amount of buried water infrastructure reaching the end of its service life, operators have every incentive to take a proactive approach to asset management.
Nowhere is this more critical than in busy urban centres. The fallout from an unexpected failure can have major societal costs, and greatly diminish public confidence in the utility.
Asset management begins with condition assessment
Successful asset management begins with condition assessment, the point at which problems and challenges are understood and shaped into definitive plans from both an operational and financial perspective.
To proactively address their pipeline conditions, operators today have access to variety of tools, technologies and engineering analysis that allow for a comprehensive condition assessment of large-diameter pressure pipes, for both water and wastewater systems.
“Unfortunately there is no ‘silver bullet’ with regard to condition assessment technologies,” said Mike Wrigglesworth, Senior Vice President of Pure Technologies. “Each pipeline is unique, and no single technology is the fix for all situations. A combination of factors, from pipe material to soil conditions, operational challenges, age, installation and third party factors will all play a role in the likelihood of failure. Combined with the consequence of failure, a risk-based approach can then be used to select the best condition assessment tool or technologies.”
Matching assessment technology with the pipeline conditions and project goals
While operators can now deploy a number of data-based tools and techniques to assess pipeline conditions, each technology also comes with varying degrees of limitation. For instance, while magnetic flux leakage (MFL) tools provide the highest resolution data for steel pipe, MFL is of limited value for concrete pipe.
Medium resolution techniques such as electromagnetics can identify localized areas of wall loss on metallic pipes such as ductile iron and steel, but not on cast iron pipe as cylinder thickness is often too thick and material properties vary considerably, negatively affecting results. In both cases, it is often prudent to deploy leak detection technologies, as studies show joint defects lead to leaks, and leaks are precursors to failure.
“Often the best solution is to use different but complementary technologies to collect robust condition data that is then evaluated using engineering analysis against a comprehensive risk of failure versus a consequence of failure analysis.”