Venturi meters from PFS integrate modern advancements upon the time-tested accuracy achieved from a quality Venturi flow primary, meaning greater versatility and mission-critical performance under a wider variety of operating conditions.
The HVT-Halmi Venturi meter difference:
Shorter Laying Length: A substantially shorter laying length than any other true Venturi available on the market yields nominal permanent pressure loss characteristics equal to or less than 6% of indicated differential.
No Annular Chambers, No Plugging: No annular chambers, so the plugging that is endemic to old meter installations is never a problem.
Linear Standard Discharge Coefficient of 0.99: True static pressure sensing at the throat and inlet piezometer taps means the discharge coefficient is 0.99 from approximately 75,000 pipe Reynolds number and above.
Ideal for Both Gas and Liquid Line Fluids: The adiabatic expansion factor is known and applicable so flow measurement of gas and steam line fluids is fully supported.
Standard Accuracy of +/- 0.50% – 2 Sigma: The HVT design has been and continues to be thoroughly tested, documented, and substantiated by calibrations conducted by independent flow labs. This substantiation confirms the 2 Sigma basis for reliability of the +/- 0.50% of flow standard accuracy statement.
Line Sizes up to 180 Inches: The HVT design has been successfully extrapolated up to 180 inch line size by means of properly designed and executed laboratory model testing as well as independent CFD (Computational Fluid Dynamics) analysis.
No Downstream Installation Effect: Based on decades of lab calibrations, there is no effect on the HVT-Halmi Venturi Meter by downstream disturbers, meaning one can safely close couple valves or other fittings on the downstream end of the meter without any concern for diminished accuracy performance.
Minimal Upstream Installation Effect: The effect of upstream disturbers such as elbows or tees is minimal. Typically, with three (3) to five (5) upstream diameters being provided, there is no error in performance.
Piping Mismatch Minimized Through Technology and Testing: Due to the special geometry of the HVT-Halmi Venturi Meter design, coupled with extensive proprietary research and development, the error introduced as a result of mismatch between piping and meter body that typically occurs in installations, is quantified and well known, and in most cases, has been determined to be minimal.
Shortened Recovery Cones: The HVT recovery cone can be shortened quite considerably without adversely affecting the accuracy of the meter, making it an ideal candidate for replacement projects involving failed ultrasonic meters, mag meters, flow tubes, orifice runs, and many other devices.