Primary element flowmeter for gas, steam and liquid

Primary element for flow measurement with gas, steam and liquid

In fluid mechanics, a flow primary element is a device used to restrict the flow of a fluid while measuring the pressure difference. The main application is flow measurement using a differential pressure transducer. This measures the pressure on both sides of the orifice to calculate the flow rate. Orifice plates, nozzles, venturis, and V-cones are flow primary element. The conditions for their installation are described in ISO 5167 norms.


Differential pressure flow measurement is one
of the most widely used measurement principles in the industry. 

Primary element for flow measurement with gas and liquids products fuji electric

The main field of application is the measurement of water in heating and cooling circuits and the measurement of steam and condensates at very high temperatures in secondary circuits.



  • Suitable for liquids, gas et steam measurement
  • Robust : only mechanical without moving parts
  • Economical
  • Easy maintenance : Associated electronics are out of the installation. No need to stop flow for equipment maintenance.
  • Devices complying with International Standards
  • Suitable for continuous flow monitoring
  • Suitable for flow regulation


Measurement principle

The aim is to create a localized restriction of the section (or constriction), within the pipeline, which will generate a differential static pressure.
Its measurement will allow the flow deduction.


Primary element for flow measurement with gas and liquids Fuji Electric helps you to choose


Fuji Electric France helps you to choose
the most suitable technology for your application


Primary elements
 Orifice plate and corner tapsIntegrated orifice plateVenturis and NozzlesAverage Pitot tubesV-ConeTM flow meter

Primary element integrated orifice platePrimary element orifices plate

Primary element  integrated orifice palte

Primary element nozzles

Primary element venturis

Primary element pitot tubesPrimary element V-cone flowmeter
Diameter mini.DN501/2 NPTDN50DN50DN15
Diameter max.DN10001/2 NPTDN800DN1500DN3000
Static pressure max.500 bar160 barToute50 bar689 bar
Temperature max.200°C120°CToute350°C450°C
Reynolds numbers>2 500>2 500>20 000>12 000>4 000
Straight length
Accuracy± 1,5 %± 2 %± 1%± 1%± 0,5%
Load lossAverageAverageAverageLowLow
ApplicationsGas, steam, corrosive and non corrosive fluids


Fuji Electric flow meters range