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Process Instrumentation

Flow Nozzle and Venturi Nozzle

Wide Range of Applications

The flow nozzle design is based on the Bernoulli equation and consists of a converging inlet section with a rounded profile and a cylindrical throat.
Thanks to its structurally rigid design, the flow nozzle provides greater dimensional stability than an orifice plate under high-temperature and high-flow conditions.

Flow nozzles are generally used to measure the flow of steam, non-viscous, abrasive, and high-velocity fluids.
These nozzles are also widely used in processes involving steam, air, water, gases, chemicals, and high-temperature applications.
A hardened internal surface option is available for use in abrasive service conditions.

High Accuracy

The design and manufacture of flow nozzles comply with the requirements of the ISO 5167 standard.
This provides an accuracy of ±1.0%.
With calibration, the accuracy can be improved to ±0.25%.

Flow nozzles compliant with the ASME PTC-6 standard are also available for power plant acceptance testing.

Applications

  • Power Generation

  • Oil Production and Refining

  • Water Treatment and Distribution

  • Gas Processing and Transmission Systems

  • Chemical and Petrochemical Industries

Special Features

  • Suitable for liquid, gas, and steam flow measurement

  • Optimum solution for steam flow measurement

  • Measurement accuracy ≤ ±0.1%

  • Repeatability: 0.1%

  • Lowest permanent pressure loss among all primary flow elements

Flow Nozzle for In-Line Installation

Flow Nozzle for Flanged Installation

Venturi Nozzle

Flow Nozzle for In-Line Installation

Description

Long-radius nozzles manufactured in accordance with the ASME standard feature an inlet profile shaped as a quarter ellipse.
To achieve accurate measurement results, the flow nozzle must be precisely centered within the pipe.

Nominal Size

50 ... 630 mm

Beta Ratio

0.2 ... 0.8

Reynolds Number

10⁴ ... 10⁷

Accuracy

≤ ±1% (of full-scale flow rate)

The accuracy can be improved to ±0.25% through calibration.

Pressure Tappings

Radius tap

291020252026

Flanged Flow Nozzle

Description

The flow nozzle manufactured in accordance with the ISA 1932 standard features a smooth, concentric inlet profile extending to the throat.
The length of the nozzle depends on the beta ratio (β).
As the beta ratio decreases, the nozzle length also decreases.

Nominal Size

50 ... 500 mm

Beta Ratio

0.3 ... 0.8

Reynolds Number

10⁴ ... 10⁷

Accuracy

≤ ±1% (of full-scale flow rate)

The accuracy can be improved to ±0.25% through calibration.

Pressure Tappings

Corner taps

291020252027

Venturi Nozzle

Description

The Venturi nozzle profile is axisymmetric and consists of three main sections:

  • Rounded converging inlet section

  • Cylindrical throat section

  • Diffuser (diverging outlet) section

The geometry of the inlet section is identical to that of the ISA 1932 standard flow nozzle.

Nominal Size

65 ... 500 mm

Beta Ratio

0.316 ... 0.775

Reynolds Number

1.5 × 10⁵ ... 2 × 10⁶

Accuracy

≤ ±2% (of full-scale flow rate)

291020252100

Note:

The design may vary depending on the nominal size and process conditions.



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