The water and sanitation sector is witnessing a significant shift in flow metering technologies, with clamp-on ultrasonic flow meters emerging as a game-changer. These meters, which utilise transit-time technology to measure flow rates in closed pipes without intrusion, are challenging traditional methods and sparking a debate on the future of flow metering.
Historically, burying flow meters has been met with scepticism due to reliability and maintenance concerns. Water industry professionals have long recalled the challenges of accessing and servicing buried inline meters. However, advancements in clamp-on ultrasonic technology are turning the tide. “The evolution of clamp-on ultrasonic technology has led to its increasing adoption for both buried and submerged applications, offering a reliable alternative to traditional flow measurement methods,” says Andy Hammond.
The benefits are clear: minimal installation effort, reduced maintenance costs, and the ability to measure flow in pipes where inline meters would be impractical. By eliminating the need for expensive chambers, bypasses, isolation valves, and supply interruptions, clamp-on flow meters drastically reduce installation costs. Moreover, they can be serviced externally, offering operational flexibility in certain scenarios.
Emerson’s Flexim MCERTS-certified FLUXUS® F721WD clamp-on ultrasonic flow meters have demonstrated long-term reliability in buried installations across the UK and Europe. With a Mean Time Between Failure (MTBF) of 36.9 years, these meters are proving to be a robust solution. The use of IP68-rated transducers and solid-state transducer coupling pads further enhances their durability, eliminating the need for coupling gels or greases.
One UK water utility has taken innovation a step further with the “coffin” chamber design for clean water network installations. This cost-effective approach involves installing the meter within a compact, reinforced chamber and then backfilling the area. The chamber is capped with a cast-iron cover, creating a robust, low-cost installation solution.
The implications for the sector are profound. As more utilities seek to optimise costs without compromising performance, clamp-on ultrasonic flow meters are set to play an increasingly vital role. The technology’s ability to function reliably in submerged environments, thanks to IP68-rated transducers and solid fluoroelastomer coupling foils, further expands its potential applications.
However, the shift towards clamp-on ultrasonic technology also raises questions. How will traditional flow meter manufacturers adapt? Will the water industry see a widespread adoption of these meters, or will some utilities remain cautious? And how will the increased use of these meters impact maintenance and operational strategies?
The debate is open, and the sector is watching closely. As we move towards 2025 and beyond, the role of clamp-on ultrasonic flow meters in water and wastewater applications is set to evolve, challenging norms and sparking further innovation. The future of flow metering is here, and it’s ultrasonic.
