Flow nozzle

Engineered primary element for DP flow measurement of high velocity, non-viscous or erosive fluids

  • ISA 1932, long radius and Venturi nozzles
  • Standards: ISO 5167, ASME MFC-3M or ASME PTC 6
  • Only short inlet and outlet runs required

ISA 1932 nozzle

ISA 1932 nozzle

A flow nozzle is an engineered primary flow element for non-viscous and erosive fluids under high velocity and pressure, which would wear or damage orifice plates. Flow nozzles are either integrated into pre-assembled meter runs, designed to be mounted in between flanges or welded into the pipe. They require less straight upstream piping and incur lower permanent pressure loss in comparison to orifice plates. There are no sharp edges exposed to wear. A number of different flow nozzle types are available, e.g. a throat tap long radius ASME PTC 6 nozzle that is typically used for performance testing of steam turbines.

Product highlights

  • Typical uncalibrated uncertainty up to ±0.8% (ISA-1932 nozzle); Optional accredited wet calibration at operating Reynolds number for uncertainties up to ±0.2%
  • Typical pressure loss down to 5% of the generated DP (Venturi nozzle)
  • Materials: Carbon steel, stainless steel and special materials
  • With weld ends, flange connection or for mounting between two flanges within the bolt circle
  • With optional annular chamber and multiple pressure taps (redundancy)
  • Size: 2…24″ (60...630 mm) per standard, larger sizes upon request
  • Low maintenance and long life with low total cost of ownership (TCO)
  • Available as pre-assembled meter run with weld-in flow nozzle

Typical applications

  • Liquid, steam and gas applications with high flow rates
  • Applications with high accuracy requirements
  • Non-viscous and corrosive fluids
  • Applications with limited space where primary elements with standard inlet and outlet runs cannot be used

Product variants

ISA 1932 nozzle

ISA 1932 nozzle

Flow nozzle with smooth centrical inlet to throat section with sharp outlet

  • Uncalibrated uncertainty: ±0.8…1.2%
  • Length depends on the Beta ratio
  • Can also be clamped between flanges
Long radius nozzle

Long radius nozzle

Flow nozzle with smooth elliptical inlet to throat section with sharp outlet

  • Uncalibrated uncertainty: ±2%
  • Two types: High beta nozzle (0.25 ≤ β ≤ 0.8), low beta nozzle (0.20 ≤ β ≤ 0.5)
  • Available as a complete meter run with weld-in section
Venturi nozzle

Venturi nozzle

Flow nozzle with a cylindrical throat and a divergent diffuser section

  • High accuracy and low residual pressure loss (uncalibrated uncertainty: ±1.2…1.74%)
  • Cost-effective design with truncated diffuser also available
  • Shorter upstream lengths than Venturi tubes

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