Flow: Venturi Flow Meter

How do I measure flow? > Flow: Venturi Flow Meter

A Venturi Meter is a device in which pressure energy is converted into kinetic energy and it is used for measuring the rate of flow of fluids through pipes.

How it Works

A Venturi flow meter contains a throat (d) which is smaller in diameter to the pipe (D), into which it fits.

When the fluid flows through it, the resultant pressure at ‘d’ is lower than the upstream pressure of ‘D’.  These pressures at ‘d’ and ‘D’ can be measured using pressure tappings and the difference in pressure can be used to calculate the flowrate of fluid in the pipe.



  • Well proven, simple, and robust metering principle
  • No moving parts


  • Presents some restriction to flow in the flare system
  • Venturi flow meter could be an option with stable high flow, but due to cost and limited turndown, it's not a likely to be chosen as backup or primary measurement for a flare system
  • High cost
  • Not suited for low flow velocities
  • Limited turndown ratio, typically 4:1

Case study

No case study available at this time.

Differential pressure meter

Differential pressure meters work on the principle of calculating a flow rate based on the change in pressure between two measured points.

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