Differential pressure measurement is a universal flow measurement for liquids, gases, and vapors. Differential pressure flowmeter always provides accurate results even with large bores, high temperature, and extreme pressure.

Primary differential pressure devices, like SITRANS F O orifice, are standardized mechanical flow sensors according to DIN EN ISO 5167 which are used for volume and mass flow measurement. The SITRANS F O orifice is suitable for non-corrosive and corrosive gases, vapors and liquids; permissible operating temperature -60 to +570 °C. The created differential pressure will be converted with the help of a differential pressure transmitter SITRANS P delta P into a proportional flow signal. For calculation of the SITRANS F O orifice to DIN EN ISO 5167 is a completed filled out questionnaire necessary.

Differntial pressure flow meter application examples: Power stations, Petrochemical industry, Chemical industry


Primaries / Differential pressure devices

-Mounting between flanges with welded connections Orifice with annular chamber or single tappings
Metering pipe with orifice plate, annular chamber or single tappings

Flanged orifice plate with flange tappings
Venturi nozzle
Classical venturi



 Nominal Sizes From DN 10 to DN 1000
From ½ inch to 40 inches
 Temperature Range From -60 to 570 °C
From -76 to 1058 °F
 Operating Pressure Max. 315 bar
Max. 4570 psi
 Process Connections Thread G½ and ½-14 NPT
cutting ring
 Orifice Material 1.7335, 1.4404. 1.4571, 1.4576 and further materials on request


  • Orifice flowmeters are very robust and can be used in a wide range of nominal diameters
  • Suitable for wide ranges of temperature and pressure
  • No calibration required as the process is standardized
  • The electronics required in addition can be used over a long distance from the measuring location
  • The differential pressure measurement is well known and has a large installed base