Fluid Components International (FCI) has introduced its ST75 Series Thermal Mass Flow Meter, a solution for engineers striving to maintain optimal oxygen (O2) purity levels in high-temperature, combustible, or confined space environments.
According to FCI, the ST75 Series Flow Meter is engineered to provide engineers with “continuous, accurate, and reliable air/gas flow measurement, all while boasting full Haz-ex approvals and a SIL rating.”
Shifting away from conventional oxygen tank systems, which present issues like unreliable purity, waste, high-pressure safety concerns, and erratic deliveries, the industry is embracing the latest generation of oxygen generators.
However, the integration of these generators within manufacturing plants necessitates precise gas flow rate and totalised flow measurement at various points in the process control loop.
Explaining the working principle of oxygen generators, the company stated, “These generators operate by separating oxygen molecules from other molecules in a clean, dry compressed air stream through pressure swing adsorption (PSA), resulting in a continuous oxygen flow at 90 to 95 percent purity.” This process isolates oxygen from other air stream components, leaving high-purity oxygen at the generator outlet.
FCI’s flowmeter technology
The ST75 Series Thermal Mass Flow Meters from FCI are seen as suitable instruments for measuring and monitoring the flow of air, pure oxygen, and various gases, catering to industries such as oil/gas, chemical, food/beverage, electronics, pharmaceuticals, pulp/paper, mining, metals refining or manufacturing, and wastewater treatment.
Key features of the ST75 Series include an in-line (spool-piece) style, no moving parts, and availability for use in pipe diameters ranging from 0.25 to 2 inches. The flow metres offer wide turndowns of 100:1 and can measure from 0.01 to 559 SCFM (0.01 to 950 NCMH). Process connections include male NPT, female NPT, and flanged options.
Emphasising the technology’s robustness, the company noted, “The electronics are housed in a rugged, IP67 rated enclosure with dual conduit ports in either NPT or M20 threading.”
Standard features include dual 4-20 mA outputs and a 500 Hz pulse output, while certain models offer additional options like HART or Modbus, NAMUR compliant 4-20 mA outputs, and SIL compliance rating.
Engineers can choose between integrally mounted or remote-mounted transmitter/electronics, with the latter option including a full digital display and the ability to be situated up to 50 feet away from the thermal mass flow sensor in the process piping.
To address challenges in areas with limited pipe straight-runs, the ST75V and ST75AV models incorporate Vortab Flow Conditioners into the spool-piece, ensuring accurate measurements in Reynolds transitional flow ranges.
“The ST75 Series boasts a complete pedigree of approvals for Division l/Zone 1 installations, including FM, FMc, ATEX, IECEx, EAC/TR CU, NEPSI, CE, PED, CRN, and SIL compliance.”
