Inline Vortex Flow Meter

The RBVF series Vortex flow meter is based on Karman (Carmen) vortex principle research and production, mainly for industrial piping dielectric fluid flow measurement, such as gas flow rate of gases (air, oxygen, nitrogen, coal gas, natural gas, chemical gas, etc.), liquid, steam and other media. The product adopted advanced differential technique, together with measurement of isolating, shielding and filtering, it had possessed better anti-vibration performance and signal stability and are used in automatic control system as flow transmitter. 

Vortex Flow Meter has 2 types Installation methods:

  • Inline Vortex Flow Meter


          Clamp(wafer type)

  • Insertion Vortex Flow Meter 


  • Principle
  • Features
  • Specification
  • Model Selection
  • Applicants
  • Download


Classified as a vortex flow meter, this device utilizes a law that was theoretically proven by Theodore von Karman in 1912. When there is a column-shaped obstruction (vortex shedder) in flowing fluid, it will generate alternating vortices downstream. The flow velocity of the fluid and the vortex generation frequency are proportional to each other. Therefore, detecting the number or pulse of vortices makes it possible to measure flow. The main method of detection involves sensing the vortex vibration with a piezo element. However, a more robust method utilises ultrasonic waves to detect the vortex vibration.

Vortex flow meters are flow sensors that detect the frequency of vortices shed by a bluff body placed in a flow stream. The frequency of the vortices is proportional to the flow velocity. Vortex flow meters are used to measure the flow of liquids and/or gases and are best suited for turbulent flow with a Reynolds number greater than 10,000. Some devices can accommodate mixed-phase materials such as steam. Others can measure liquids with suspended solids (slurries). The advantages of this device are low initial set up costs, and low maintenance requirements when used in clean flow conditions. Vortex flow meters are also insensitive to temperature, pressure, and viscosity. The disadvantage of a vortex flow meter is that there is a low to medium pressure drop due to the obstruction in the flow path.


The basic principle for a vortex flow meter is that a barrier is placed in a moving stream. As the flow goes around the object it alternates creating vortices (swirls of media) from the top or bottom of the object. The swirls are created from the increase in pressure and decrease in velocity on one side of the object and a decrease in pressure and increase in velocity on the other side. This process creates a swirl on one side of the object and as the process alternates, a swirl is created on the other side.

The RBVF Series Vortex Flow Meter Features:
  • No moving mechanical parts
  • Low maintenance
  • Low pressure loss 
  • Large measuring range
  • High accuracy
  • High reliability
  • 24V or Battery powered
  • Temperature and pressure compensation 

The RBVF Series Vortex Flow MeterSpecification:


Main Technical data

Fluid Type

Steam, Gas, Liquid

Nominal diameter(mm)

25,40,50,65,80,100,125,150,200,250,300, (300~1000 Insert type)

Nominal pressure


DN25-DN200 4.0 (>4.0 clarify),

DN250-DN300 1.6 (>1.6 clarify)

Connection type



Body Material

SS304(1Cr18Ni9Ti) or customize


Inline type

±1%R, ±1.5%R,±1FS;

Insert type:


Range of


Power supply voltage

Sensor: +12V DC, +24V DC; Transmitter: +12V DC, +24V

Dual power: 24VDC + Battery

Battery: 3.6V

Output signal

Square wave pulse (not including the battery power supply type): high level or low level5V,1V; current: 4~ 20mA

Protection grade



Diving type


vibrating acceleration  

piezoelectric type:  





Medium temperature

Piezoelectric Type

(-50 ~ +260) ℃, (-50 ~ +320) ℃

Capacitive Type

-40~300, -40~400,-40~450

Power Supply

The three-wire system and the two-wire system

Three-wire System

When using external power supply: 12 ~ 24VDC/30mA (-20% ~ +15%), no output can be as low as 9V

Three-wire System

When battery-powered (optional): Lithium battery 3.6V (2-13Ah) / 0.3mA.

Output Signal

Three wire system and two wire system

Transmission distance

3-line pulse:


Output: system and two wire system



Pulse (except battery type)

High level≥6V

Low level: ≤1V



Road resistance




ExdⅡia CT2-CT5



Ambient temperature

         (-30 ~ +55) ℃



Atmospheric Pressure


Model Selection

The RBVF Vorex Flow Meter Model Selection: 

Vorex Flow Meter


The RBVT Series Vortex Flow Meter Applications:


  • Energy Measurement: Energy into primary energy (coal, crude oil,coal bed methane, LPG and natural gas), secondary energy (electricity, coke,artificial gas, refined oil, liquefied petroleum gas, steam) and energycarriers working fluid (air, oxygen, nitrogen, hydrogen, water);
  • Industrial Production: Widely are used in metallurgy, electricpower, coal, chemical, petroleum, transportation, construction, textile, food,medicine, agriculture, environmental protection and people's daily life, andother fields of national economy, the development of industrial andagricultural production, energy conservation, improve product quality animportant tool to improve economic efficiency and management level plays animportant role in the national economy.
  • Environmental Protection: Flue gas emissions, waste, sewage andother heavily polluted air and water, a serious threat to the humanenvironment. National sustainable development as a national policy,environmental protection will be the biggest problem of the 21st century.Pollution of air and water to be brought under control, we must strengthenmanagement, and infrastructure management is a quantitative amount of pollutioncontrol.
  •  Transportation: There are five ways: Railway road, air, water,and pipeline transport. Wherein the pipeline transport, although it has longbeen, but the application is not common. With the outstanding environmentalissues, pipeline transport characteristics attracted people's attention.Pipelines must be equipped with the meter, it is the control, allocation andscheduling eyes, is also not safe and economic accounting supervisor essentialtool.

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