Fabricated Venturi Low Flow Meter

FV-LF Fabricated Venturi – Low Flow

+/- 0.50% Uncalibrated Uncertainty
Low Reynolds, Lower Loss

  • Line size: 3/8 to 12 inches
  • Head loss % of Differential: 20.0 to 40.0 percent
  • Recommended pipe Reynolds number: Greater than 6,000 for basic accuracy

The Fabricated Venturi Low Flow Meter is a specially designed meter combining performance elements of both orifice and venturi type devices and provides an accurate solution for wide range flow applications.


Based on the highly successful PFS HVT design, which performs exceptionally down to 75,000 Reynolds, the FVLF low flow meter further increases the stable range of accurate flow measurement down to 6,000 Reynolds. The trade off 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.


Line Size
3/8 to 12 inches
Head loss % of Differential
20 to 40 percent
Basic Accuracy (% of Total)
+/- 0.25 to 0.9 beta dependent, +/- 0.25 (Calibrated)
Minimum pipe Reynolds number
Must be greater than 6,000
Required Straight Piping
2D – 13D
Beta Range
0.30 through 0.75
Useful Service Life
Very Long
Service Functional Limits
Clean liquids & gases
Raw Water, Wellfields, WTP Influent / Effluent, Pumping Stations, Water Distribution, Billing, Reclaimed Water, Industrial, Commercial, Oil and Gas
Common Materials
Carbon Steel, Stainless Steel, Chrome Moly
Other Available Materials not limited to
Aluminum, Zirconium, Hastelloy, Monel, Duplex SS, Titanium, Tantalum, 321SS

Support and Service

In addition to a wide range of differential producing Venturi flow meters, orifice plates, WedgeType™ flow meters, and open channel flow elements, PFS provides comprehensive, specialized services for new and existing flow meters, including rehabilitation, hydraulic analysis, and full engineering support.


ISO 9001, ASME S&U, PED Certified, CRN.

See all certifications