ISA 1932 Venturi Nozzle Whole

Venturi Nozzle

+/- 1.21% to 1.74% Uncalibrated Uncertainty
Liquids and Gases, Lower Loss

  • Line size: 2.5 to 20 inches
  • Head loss (permanent pressure loss) in % of Differential: 5% to 20%
  • Recommended Pipe Reynolds Number: Greater than 150,000 for basic accuracy


The Venturi Nozzle is a hybrid device having an inlet, convergent section identical to the ISA 1932 nozzle and an outlet, divergent section similar to a Venturi tube flowmeter. This results in a unique location for the low pressure tap in the throat. This design has a lower pressure loss than the ISA 1932 nozzle and the long radius nozzle.

They are generally used for the measurement of liquid or gas flows including steam, erosive, high-velocity and non-viscous media. They do not rely on a sharp edge (which can deteriorate over time) to maintain accuracy and therefore offer excellent long-term accuracy with less wear, reducing the possibility of distortion. They are often used for high accuracy flow measurement in power plant applications.


Line Size
2.5 to 20 inches
Head Loss (permanent pressure loss) in % of Differential
5% to 20%
Basic Accuracy (% of Total)
[Calibrated +/- 0.25%] [Uncalibrated +/- 1.21% to +/-1.74%, Beta Dependent]
Recommended Pipe Reynolds Number
Greater than 150,000 for basic accuracy
Required Straight Piping
Consult PFS for required US & DS piping based on your specific application
Beta Range
0.316 through 0.775
Useful Service Life
Medium to Long
Service Functional Limits
Clear Liquids, Gas and Steam
Power Generation, Hydrocarbon, Liquids, Gas Process, Water Treatment distribution, Oil production and refining, Steam Process, High Velocity Process, Erosive Fluids
Common Materials
Carbon Steel, Stainless Steel, Chrome Moly
Other Available Materials not limited to
Aluminum, Zirconium, Hastelloy, Monel, Duplex SS, Titanium, Tantalum
Several international codes govern use and design of flow nozzles, ASME, ISO and others. While they cover similar meter embodiments, design parameters and requirements, stated performance in key areas they may differ.

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.

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