This facility signifies the importance that HK places on controlling unaccounted water (UFW) in its UWSS. The Q-Leak test and training system includes three pipe loops with pipes of different materials (galvanized iron, ductile iron, mild steel, and polyethylene) and sizes, and as many as 80 access points. The distinguishing characteristic of the Q-leak system is the different soil bedding types in which the pipe system is buried. The water mains are covered with grass block, paving block, non-reinforced concrete, reinforced concrete, and bituminous materials, which are all commonly used pavement surface found in Hong Kong. Consequently, Q-leak is the most appropriate facility/environment for evaluating effects of the surrounding soil cover on TR-HF wave imaging.
It is worth highlighting that this system has been specifically designed to have the complexities of real-world systems with various water flow patterns, but the system is completely isolated from the city network, eliminating any effects produced by consumer demands. Moreover, the system is outfitted with conventional defect detection technologies (e.g., step test, noise logging, leak noise correlators, ground microphone, hydrophone, and inline inspection methods, electromagnetic/pipe cable locating, ground penetrating radar). Flow can range from static to laminar and all the way up to highly turbulent flow (Reynolds number = 0 to 5×10^5) and Mach number = 0 to 7.5×10^(-3). The facility is flexible to provide a controlled testing environment to validate time-reversal theories.