Non-Invasive Measurement With Emerson’s New Ultrasonic Flow Meters

Emerson’s new Flexim FLUXUS / PIOX 731 series is made up of ultrasonic flow meters that can be configured to work on virtually any process fluid, gas or liquid. It simply clamps onto the pipe, making non-intrusive volumetric or mass flow measurements without the need to stop production for insertion, removal, or maintenance.

Emerson’s FLUXUS F/G731 ultrasonic flow meter is the Flexim 731 series’ general-purpose model. Image used courtesy of Emerson

Ultrasonic Flow Measurements

One of the major challenges with any measurement, including flow measurements in fluid systems, is getting an accurate reading without disturbing the system. There are a number of ways to make flow measurements, many of which can affect the quantity being measured. For example, flow measurements that are based on differential pressure through a critical orifice will affect the flow rate over time, as suspended particles can fall out of the solution and build up, further restricting flow.

Other intrusive pressure measurement devices, such as turbine sensors that use the Hall effect, require periodic maintenance. Because they are in the process stream, preventative maintenance requires a full shutdown.

Ultrasonic measurements are performed outside of the pipe, so they do not form any sort of constriction or pressure change during measurement. These types of measurements are not intrusive and have few moving parts, meaning production can continue when maintenance is required.

Flexim FLUXUS / PIOX 731 Series

Emerson’s new Flexim FLUXUS / PIOX 731 series of ultrasonic flow meters is designed to be modular and meet relevant standards for use around flammable vapors (ATEx, IECEx, EAC, and others). They have built-in correction factors for “wet” gases and for handling disturbed flows, which often fool other flow measurement instrumentation. All models can run on 120 V/240 V AC, as well as 11-32 V DC, and have a USB-C port for programming and data extraction.

The Flexim 731 series features nine models to suit a variety of applications in various industries, including oil and gas, chemical, and manufacturing. Image used courtesy of Adobe Stock

Model numbers vary by their application. The F/G731 GP is the series’ general-purpose model that will be useful for most industries. For pipelines, the H731 HPI model provides leak detection, density measurements, and a few other capabilities. The PIOX S731 model provides compositional data, making it suitable for the petrochemical industry. For non-chemical process industries, the G731 CA monitors compressed air, and the G731 ST-LT/HT monitors low- and high-temperature steam.

Flow Measurement Solutions

The ability to quickly install and configure the Flexim 731 series in a non-intrusive way makes it useful in many industries, as it can be used to monitor compressed air lines and steam lines. This can help identify leaks, and while steam leaks are relatively easy to identify, the loss of compressed air is a major expense for most industries. Other process fluid leaks can be detected by keeping a record of measurements from these flow meters.

The Flexim 731 meters could also be used for process safety applications when preventative maintenance is required. For example, suppose blanks need to be installed along a pipeline to stop flow. By integrating a clamp-on ultrasonic flow meter, technicians can verify zero flow before performing the maintenance.