Buildings Award of Excellence
Hot Pipeline Condition Assessment Study CIMA+
Environmental significance Hot water systems convey not only water, but also chemicals designed to allow the water to run at high temperatures and to provide a corrosion barrier for the internal surface of the pipeline. The water is in a closed-loop pipe system; any drainage is conducted within that system, using storage in boilers. So, any unexpected failures and main breaks would lead to hot water spills that could present a health and safety hazard, due to high temperatures and the chemicals 36
CANADIAN CONSULTING ENGINEER
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“The acoustic monitoring technique they used to assess the wall of the pipes was ingenious. They adapted geophysics to something that’s not in the ground, which is quite unusual.” - Jury
that could reach major watercourses and/or combined sewer systems around the airport. The spilled water could eventually reach treatment plants and cause significant issues to the treatment process, due to the highly concentrated chemicals in the water. A novel approach to acoustics GTAA needed to develop an assessment method for challenging pipeline systems where the carrier is inside a conduct, given the limitations and constraints resulting from system operating conditions (i.e. high temperatures) and their limited tolerance for inspection
risks, with preference given to external, non-invasive tools. Acoustics is a well-known technology for inspecting potable watermains and buried pipelines, but it is limited to those installed in a compacted backfill, not in a void like GTAA’s hot pipeline setup. When an acoustic stress wave is introduced on a pipe’s external wall surface (i.e. by tapping with a rubber hammer on the external surface), it will vibrate at a macroscopic level, causing radial displacements that affect the sound wave velocity inside the hot water body. When a pipe is not compacted in backfill, the boundary conditions for equilibrium are not
PHOTOS COU RT E SY C I M A+.
T
he Greater Toronto Airports Authority (GTAA) owns and operates hot-water closed-loop pipeline network, with carbon steel pipes operating at high temperatures to ensure continuity for Toronto Pearson International Airport. The GTAA engaged CIMA+ to develop a conditional assessment for these pipelines, based on its own inspection standards, and thus avoid unnecessary shutdowns and/or using invasive tools. Based on the findings of CIMA+’s study, this year the GTAA has completed an inspection of the entire population of hot-water pipes at Canada’s largest airport, while they are in service and fully operational.
September/October 2021
2021-10-18 10:14 AM
