Ultrasonic Flowmeters

Ultrasonic Flowmeters

Ultrasonic flowmeters determine flow by transmitting ultrasonic signals between sensors and comparing the transit times with and against the direction of flow. In the differential transit-time method, the time difference between upstream and downstream signal paths is proportional to flow rate, enabling accurate velocity and volume flow calculation without introducing an obstruction into the pipe.

Ultrasonic technology is valued for its versatility across gases and liquids and for the ability to measure flow independent of electrical conductivity. For homogeneous fluids, measurement can be largely independent of pressure, density, temperature, conductivity, and viscosity within the device’s specified limits. Inline designs are typically selected when traceable, guaranteed accuracy is required, while clamp-on designs mount on the outside of the pipe to enable retrofits and temporary measurements without process interruption. Clamp-on sensors can be applied to many pipe materials - including metals, plastics, and lined constructions - supporting measurement in both new builds and legacy networks.

Key benefits include a free pipe cross-section with no added pressure loss, no moving parts, and long service life. Clamp-on measurement avoids direct contact with the process medium, supporting aggressive fluids, high-pressure services, and installations where shutdown is not acceptable. The availability of both in-line and clamp-on construction supports both permanent metering and temporary verification.

Typical applications range from water and wastewater networks and industrial cooling water to chemical and specialty services where noninvasive measurement reduces exposure and simplifies installation. Clamp-on meters are commonly used for retrofit flow balancing, energy audits, and troubleshooting, including very large pipe sizes (up to DN 4000 in many offerings). Inline ultrasonic meters are used for higher-accuracy duties such as custody transfer and large-line metering in oil and gas and LNG services.

Selection considers the acoustic properties of the fluid, pipe material and liner, and the presence of bubbles or solids that can attenuate ultrasound. For clamp-on installations, sensor spacing, coupling quality, and correct pipe data are critical. When paired with diagnostics and digital connectivity, ultrasonic meters can provide continuous confidence in measurement while enabling rapid deployment across a broad installed base.

Engineered Equipment Company, a leading supplier of specialized industrial equipment.