Subsonic Venturis offer the best repeatability and pressure recovery of the subsonic meters offered by Flow Systems, due to the continuous geometry of the contraction, throat, and divergent sections. The low overall pressure loss characteristic of a Venturi, reduces operating costs and head requirements of prime movers in systems. Experience has shown that Venturis have less stringent up and downstream piping requirements than other subsonic meters offered by Flow Systems.
Variations in Geometry
Flow Systems offers Venturis with several geometries. A particular geometry may be recommended by our application engineers based on the user’s specific application, compliance requirements, beta ratio (throat diameter to inlet pipe internal diameter) and line size, in order to determine the best combination of performance and economy. Classical Herschell Type Venturis consist of a conical inlet section, cylindrical throat section, and conical divergent section. Meters with line sizes less than 8 inches are machined, while larger line sizes are fabricated. Beta ratios are offered from 0.4 to 0.75. Circular-Arc Venturis have a radial converging section, cylindrical throat section, and a conical divergent section. This geometry is applicable for line sizes below 8 inches and for low beta ratio meters. An ASME Flow Nozzle which has an elliptical converging section and cylindrical throat section can be combined with a conical divergent section to produce a hybrid Venturi. This geometry works well for any beta ratio and is currently available in line sizes up to 20 inches.
Performance Charts by Gas
The following are examples of subsonic Venturis manufactured by Flow Systems.