Long Radius Nozzle Whole

Long Radius Flow Nozzle

+/- 2.00% Uncalibrated Uncertainty
Liquids and Gases, High-Velocity Flow

  • Line size: 2 to 24 inches
  • Head loss % of Differential: 30 to 85 percent, Beta Dependent
  • Recommended Pipe Reynolds number: Greater than 10,000 for basic accuracy


The Long Radius Flow Nozzle is generally used for the measurement of liquid or gas flows including steam, non-viscous, erosive and high-velocity media. It does not rely on a sharp edge (which can deteriorate over time) to maintain accuracy and therefore offers excellent long-term accuracy with less wear, reducing the possibility of measurement error over time.

Flow nozzles are capable of measuring higher flow rates, often double, than an equivalent orifice plate at the same differential pressure. The flow nozzle is available in various designs including mechanically clamped between flanges or permanently welded directly into the pipe line.


Line Size
2 to 24 inches
Headloss % of Differential
30 to 85 percent, Beta Dependent
Basic Accuracy (% of Total)
(Calibrated) +/- 0.25 (Uncalibrated) +/- 1.00 to +/-2.00 (PTC19.5, MFC3M)
Minimum Pipe Reynolds Number
Greater than 10,000
Required Straight Piping:
Consult PFS for required US & DS piping based on your specific application
Beta Range
0.20 through 0.80
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, 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.

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