Posted on: February 17, 2021 Posted by: hexaone Comments: 0
flow measurement instruments

A flow meter is a tool that estimates the flow rate of a liquid. Flow meters are flow measuring tools used to calculate the direct, nonlinear, size, or volumetric flow rate of a gas or a liquid. Flow meters are also called Flow Gauges.

Kinds of Flowmeters

Volumetric Flowmeters

Volumetric Flowmeters

It is a meter that measures the fluid mass passing through a precise location in a given time. Volumetric flow meters provide an instant analog, digital, or throb output of the liquid or gas. Various kinds of Volumetric Flowmeters are available, as listed below

  • Differential Head type
    • Orifice plates
    • Venturi meters
    • Annubar
  • Differential Area type (Rotameters)
  • Electromagnetic flowmeters
  • Ultrasonic flowmeters
  • Turbine flowmeters
  • Vortex flowmeters
  • Positive Displacement Meters

Mass Flowmeters

Mass Flowmeters

  • Mass flow meters calculate the fluid mass flow rate that travels by a tube per unit of time. There are two kinds of mass flowmeters as stated belowCoriolis Mass flowmeter and
  • Thermal Mass flowmeters

Differential Head Type Flowmeters

Differential Head Type Flowmeters

  • The pressure difference endures between the upwards & downwards sides of a little fluid stream restraint linked to the square of fluid speed.

Where Q = Amount of flow rate and ▲P = Differential pressure within taps.

Orifice plates

Orifice plates

  • Concentric orifice plate: Most often used
  • Segmental & Eccentric orifice plate: Used for fluids holding dissolved solids.

Traits of Orifice Plates

  • Design Force: No restriction. Defined by DP transmitter
  • Design Temperature: No condition. Defined by DP transmitter
  • Sizes: Supreme size is the pipe size
  • Flow range: restricted only by pipe size.
  • Fluids Applications: Cryogenic / clean gases
  • MOC: No restriction

Venturi Meters

Venturi Meters

  • A venturi tube also scales flow rates by contracting fluids and holding a differential pressure drop.
  • In the upward cone of the Venturi meter, speed is raised, the pressure is lowered.
  • Pressure drop in the upstream cone is used to calculate the rate of flow through the instrument.

Traits of Venturimeters

  • Design Pressure: No restriction. Defined by DP transmitter/ pipe press.
  • Design Temperature: No restriction. Defined by DP transmitter/ pipe pressure ratings
  • Sizes: 25 mm to 3000 mm
  • Fluids/ Uses: Clean Liquids/ clean gases
  • Limited uses: Dirty /caustic/viscous Liquids & Dirty gases
  • Flow range: bound only by pipe size and beta ratio.

Benefits of Venturimeters

  • Lower head lacks than orifice plates are reducing the capital cost on save pump energy costs.
  • No check process for the change of DP transmitter.
  • It can be used for temperature limits.
  • Cryogenics or High Temperatures

Annubar Flowmeter

Annubar Flowmeter

  • The analysis is fitted in the media line as a pressure sensor.
  • With the flow, the probe reports both the static and the active pressure via the probe openings.
  • In the minus chamber of the annubar, resting on the reverse side, only the static pressure has any result.
  • The differential pressure replies to the dynamic force in the pipeline & the flow can be measure instantly.

Traits of Annubar Flowmeters

  • Design Pressure: Up to 97 bars 55 bars
  • Design Temperature: Upto 400 Deg C
  • Sizes: 50 mm to 3000 mm
  • Fluids: Clean Liquids, gases, and steam
  • MOC: Brass, steel, stainless steel

Benefits of Annubar flowmeters

  • The entire complex head permits the direct mounting of DP electronics.
  • Hot tapping: Insert/ installation without system shutdown
  • Very low-pressure drop

Variable Area Flowmeters or Rotameters

Variable Area Flowmeters or Rotameters

  • A free-moving float is evaluated inside a narrow vertical tube.
  • As the fluid flows upward, the float stays uniform when the active forces working on it are zero.
  • The flow rate is shown by the state of the float related to a measuring scale.

Design Traits of Rotameters

  • Design Force: Upto 350 PSIG / 720 PSIG.
  • Design Temperature: Upto 400 Deg.C / 538 Deg.C .
  • Sizes: upto 75 mm
  • Fluids/ uses: filtered liquids, gases
  • Flow velocity: upto 920 cub.m/hr for fluids & 2210 cub.m/hr
  • MOC: Borosilicate glass, brass , steel, stainless steel

Benefits of Rotameters

  • Easy, robust, and direct output
  • It does not need external pressure or lead lines.
  • The pressure reduction is minimal and somewhat even.

Magnetic Flowmeters

Magnetic Flowmeters

  • Work on Faraday’s Law of magnetic induction.
  • When a conductive fluid flows in a magnetic field, a voltage is formed between two electrodes at right angles to the fluid speed and field bearings.
  • The flow tube has a firm area & field strength, so the increased voltage is directly equal to the volumetric flow rate.

Design traits of Magnetic Flowmeters

  • Design Force: 20 bars to 172 bars
  • Design Temperature: Upto 120 deg.Cs / 180 Deg.C
  • Sizes: 2.5 mm to 3000 mm
  • Fluids: Liquids can be clean, corrosive, and dirty
  • Velocity : upto 10 m/s
  • MOC: ceramic, teflon, rubber

Benefits of Magnetic Flowmeters

  • Flow rate unchanged by fluid mass, density, thickness, disorder, or piping configuration.
  • Highly reliable due to the lack of moving parts/ outer sensing lines
  • Rust free applying Teflon liner and platinum electrodes
  • Huge flow measuring scales & no pressure drop

Vortex Flowmeters

Vortex Flowmeters

  • An obstacle is placed over the pipe bore at a right angle to liquid flow.
  • As fluid flows, vortices are shed from rotating sides of the body & this dropping cycle is directly equal to fluid speed.
  • Exposure of the vortices using force changes in the vortex stream.
  • Rate of creation of vortices directly equal to the flow rate.

Design Traits of Vortex Flowmeters

  • Design Force: 138 bars
  • Design Temperature: -200 Deg. C to 400 Deg. C
  • Sizes: 15 mm to 300 mm
  • Fluids: Gases and clean fluids
  • Velocity: 0.3 to 10 m/s (liquids) and 6 to 80 m/s (gases)
  • MOC: majorly in stainless steel, few in plastic

Benefits of Vortex Flowmeters

  • Less maintenance, no shifting parts.
  • Rotation using fluid flow is not needed & unchanged by thickness, mass, pressure, and temperature within working term.
  • Digital or analog production.


Therefore, these are the best flow meter that can be used in various applications. We serve you the best possible rates and quality products. Our flow meters provides you the precise flow measurement and are easy to install. These flow gauges ideal for use in all kinds of industries. I hope the information guided you. If you are planning to buy flow meters. You can explore our site, where you will find the best flow meters of your choice.

Author Bio:

Naman Modi is a Professional Blogger, SEO Expert & Guest blogger at, He is an Award-Winning Freelancer & Web Entrepreneur helping new entrepreneur’s launches their first successful online business.

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