BVTIFWyatt Venturi Tubes
Insert-Type Fabricated Primary Elements


  • Low Pressure Loss
  • High Accuracy
  • Low Installed Cost
  • Custom Designed
  • Short Laying Length


The Wyatt BVT-IF is a fabricated insert venturi flow element that offers repeatability and accuracy over a greater range of flow rates and has lower permanent pressure loss than orifice plates, flow nozzles, or traditional venturi meters. These units can be manufactured from virtually any material to address the needs of your applications. The BVT-IF is designed for insertion within the interior of a pipeline and is secured by the adjacent pipe flanges. These venturi elements are characterized by longevity of service and flexibility in design.


The fabricated insert BVT-IF is designed to measure the flow of gases and liquids that have low solids loading. The BVT-IF can operate over extreme temperature and/or pressure ranges with highly corrosive fluids or gases. The BVT-IF has the distinct advantages of minimal weight, cost, and laying length. Typical applications range from potable water, cooling water, process water, steam, air flow for fine bubble aeration, combustion air, and natural and process gases.

Flow Measurement Accuracy

For pipe Reynolds numbers greater than 75 000 and a normal-ized piping configuration, the Wyatt Venturi Tube provides a flow measurement accuracy of ± 0.50% without flow calibration. With independent flow calibration, Wyatt Engineering’s insert BVTs provide the user with ± 0.25% accuracy.

BVT-IF Technical Specifications


For pipe Reynolds numbers greater than 75 000 and a normalized piping configuration, the Wyatt Venturi Tube provides a flow measurement uncertainty of:

± 0.50% for standard meters and
± 0.25% for flow calibrated meters

Headloss Comparison

Pressure Loss

The permanent pressure loss of the BVT-IF is significantly lower than that of short-form venturis, and for most beta ratios, lower than that of long-form venturis as well (See Figure 1).

Beta Ratio

Wyatt can furnish BVT-IF meters with a wide range diameter ratios (d/D). This provides users with accurate flow measurement over a broad range of flow rates for a given line size.

Temperature Range

The fabricated series of the BVT-IF can operate over a fluid temperature range of -325 °F to +1200 °F (-200 °C to +650 °C).

Pressure Range/Flange Connections

The BVT-IF is designed to operate within the pressure boundary of 4000 PSIG (27 500 kPaG) and can be manufactured to interface with any flange geometry.

Piping Requirements

Designed for full-pipe flow, BVT flow meters can be mounted horizontally or vertically. For recommended upstream piping, refer to Wyatt Engineering Technical Manual for the BVT.

Design Concepts

The hydraulic design produces discharge coefficients that are highly predictable and independent of line size. The BVT-IF design allows accurate calculation of expansibility factors that are necessary for compressible fluid flow measurement. The smooth transition section minimizes flow noise and erosion.

Signal-to-Noise Ratio

Within the specified flow range and piping conditions, the BVT-IF will produce signal-to-noise ratios greater than 98%. This level of performance is essential for sensitive process control and reactive rate-of- flow control applications.

BVT-IF Available Options


Materials of Construction

The nature of the BVT-IF fabricated design allows the flow element to be constructed from practically any material. Examples of some of the alloys employed:

  • Carbon Steel
  • 304 Stainless Steel
  • 316 Stainless Steel
  • Inconel
  • Hastelloy B & C
  • Monel
  • Titanium
  • Chrome Molybdenum
  • Nickel
  • Tantalum
  • Zirconium
  • BVT-IF

Consult your local representative or Wyatt Engineering for information on other materials of construction.