Providing Reliable Flow Measurement since 1983

Venturi Low Flow Meter

Development of Venturi Low Flow Meter

The FVLF is a specially designed venturi meter combining performance elements of both orifice and venturi type devices. Based on the highly successful PFS HVT design, which performs exceptionally down to 75,000 Reynolds, the FVLF further increases the stable range of accurate flow measurement down to 6,000 Reynolds. The tradeoff for increased low flow stability is an increase in overall pressure loss. However, unlike an orifice device, there is significant pressure recovery in the outlet divergent region of the FVLF leading to considerably less overall pressure loss than an orifice plate type meter.

FVLF Applications

The FVLF is ideally suited for a wide range of municipal, oil and gas, and industrial applications where there is a wide turn down. Due to some portion of the flows operating in a low pipe Reynolds number range, these applications are not ideally suited for a traditional venturi meter.  The FVLF is ideally suited for liquid, gas and steam applications and can be equipped with a wide range of secondary instrumentation options which extend the normal operating range of 10:1 to 100:1 or greater.  Some application examples are:

  • Municipal raw or finished water from both wellfields and in-plant processing
  • Municipal effluent pump stations (using the PFS-SMS sealed metering system option)
  • Any type of custody transfer or billing application
  • Industrial processes including beer and wine production facilities
  • Upstream, mid-stream and downstream oil and gas/chemical applications.

Another area to apply the FVLF design is in the replacement of other types of meter technologies that fail to meet the requirements for accuracy, repeatability and range.

FVLF Specifications

The basic accuracy of the FVLF is +/-0.5% of rate down to a pipe Reynolds number of 6,000; +/-0.25% of rate of liquid applications with laboratory flow calibration, and +/-0.4% of rate with a gas calibration.  Another significant advantage is the very short upstream straight pipe requirements, which are zero upstream and downstream straight pipe with lab model calibration.

Materials of construction are essentially any material that is suited for the application requirements including carbon steel, stainless steel, Monel, Kynar, and PVC.

Download our Product Data Sheet to get further specifications, features and more information about these low flow venturi meters. 

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