Vortex Flowmeters

History of Vortex Flowmeters

In 1878, while investigating the phenomenon in which a wire stretched in an airflow produces sound, Czech physicist Vincenc Strouhal discovered that the vortex shedding frequency is proportional to flow velocity. In 1911, Hungarian mathematician and physicist Theodore von Kármán theoretically demonstrated that when an object is placed in a fluid, vortices are spontaneously generated alternately on either side in its wake, a phenomenon known as the Kármán vortex street. Based on these research findings, the principle was established of calculating flow velocity and flow rate by measuring the number of vortices generated. In the late 1960s, research progressed on applying this principle to industrial measurement, leading to the practical realization of the vortex flowmeters we know today.

History of Yokogawa’s Vortex Flowmeters

Having established technology for measuring vortex generation, Yokogawa Electric Works, Ltd. launched the world’s first insertion-type vortex flowmeter for flare stacks in 1969. In 1979, we launched the general-purpose vortex flowmeter YEWFLO Style A. In 1981, we followed up with YEWFLO Style C, which formed the basis of the present sensing structure. In 1992, we introduced YEWFLO Style E, which excelled in noise resistance. In 2000, we launched the digitalYEWFLO series, which have our proprietary digital signal processing technology (SSP) and improved resistance to vibration. This digitalYEWFLO series was a pioneering new stage for vortex flowmeters due to its automatic noise removal functions and diagnostic functions.
Furthermore, to meet various needs and support applications of our customers, the YEWFLO series has continuously evolved. In 2002, we released the Built-in Temperature Sensor type that can measure saturated steam flow with a single unit. In 2006, we introduced the Reduced Bore type for smart piping. Moreover, in 2012, we launched large-diameter models (up to 400 mm), further expanding the product lineup, and in 2022, we launched the latest VY series, continuing the history of YOKOGAWA's vortex flowmeters.
Sales of over 500,000 units are a testament to Yokogawa’s measurement technology accumulated over many years and its high product quality.

Measurement Principle of Vortex Flowmeters

We have now covered the history of vortex flow meters. The following page provides a detailed explanation of the measurement principle.

> Basics of Vortex Flowmeters: Measurement Principle and Measured Fluids 
* Available in Resources (Tutorials).

Fluid Simulation of Karman Vortices Generation

What Applications Are Vortex Flowmeters Suitable For?

Vortex flowmeters are highly versatile flowmeters capable of measuring liquids, gases, and steam over a wide range of temperatures and pressures. As a result, they are widely used for both process fluids used as final products or raw materials in manufacturing processes, and utility fluids that support plant operations.

• Liquids: Industrial water, Cooling water, Fuel oil, Chemical liquids, Pure water, Liquid nitrogen
• Gases: Compressed air, Fuel gas, Nitrogen gas, Air/Oxygen
• Steam: Saturated steam, Superheated steam

In recent years, the application of vortex flowmeters has been expanding for the visualization of energy usage of utility fluids such as water, fuel, air, and steam, from the perspectives of improved energy efficiency, cost reduction, and CO₂ emissions management. In addition, even in applications where steam flow rates fluctuate widely depending on batch processes or line operating conditions, the wide rangeability (measurable flow range) of vortex flowmeters enables them to cover a wide range of flow measurement with just a single unit.

Differences between Vortex Flowmeters and Other Flowmeters

We briefly introduce the key differences between vortex flowmeters and three other representative types of flowmeters.

Advantages of Vortex Flowmeters over Differential Pressure Flowmeters

• Throttling structure such as orifice plate are not required, resulting in relatively low pressure loss.
• Additional equipment such as impulse lines and three-valve manifolds are not required, resulting in reduced maintenance requirements.
• With wide rangeability and a vortex frequency proportional to the flow rate, measurement data is easy to handle.

 Advantages of Vortex Flowmeters over Magnetic Flowmeters

• Measure gases and steam in addition to liquids.
• Measure liquids with low electrical conductivity such as pure water and oils.
• Measure high-temperature, cryogenic, and high-pressure fluids such as superheated steam, liquefied natural gas (LNG), and liquid nitrogen.

 Advantages of Vortex Flowmeters over Coriolis Mass Flow Meters

• A broad range of measurement conditions such as steam and compressed air, combined with a wide selection of connection sizes, enables the measurement of various utility fluids
• A simple structure reduces weight, installation space, and low pressure loss, and provides high durability
• A relatively low initial cost per instrument enables multi-point installation for energy management applications, which in turn contributes to improved visualization of overall plant conditions

What Is the Required Straight Pipe Length for a Vortex Flowmeter?

To stabilize flow turbulence, certain lengths are required on the upstream and downstream sides of a vortex flowmeters. These are referred to as the straight pipe lengths, and the required distance is called the required straight pipe length. Details of straight pipe lengths are explained on the following pages.

> Required Straight Pipe Lengths for Vortex Flowmeters
* Available in Resources (Tutorials). 

Animated Flow Turbulence simulation in a Double Bend-Pipe

A Wide Product Lineup for Various Applications

Our vortex flowmeters support customers in various situations based on the Total Insight concept. In addition, we offer optimal solutions with a wide product lineup that supports flow measurement of liquids, gases, and steam. It's simple and rugged structure with no moving parts offers high reliability and durability.
For more detail information, please check the page of Vortex flowmeter VY Series.

General Type: The Standard Model of Our Vortex Flowmeters

The General Type is the standard model of our vortex flowmeters, and is suitable for a wide range of applications. The Long Neck Type suitable for thermal insulation workability is also available.

Built-in Temperature Sensor Type: Simultaneous Measurement of Flow Rate and Fluid Temperature

The Built-In Temperature Sensor Type has a temperature sensor (Pt1000) built into the vortex shedder bar, enabling simultaneous measurement of flow rate and fluid temperature. This makes it the most suitable model for steam applications. Based on the measured temperature, it can calculate mass flow rate and the energy content of saturated steam, enabling visualization of steam consumption, which in turn contributes to energy cost reduction and CO2 emissions reduction. The Long Neck Type suitable for thermal insulation workability is also available.

High-Temperature/Cryogenic Type: Measurement in High-Temperature and Cryogenic Fluid

The High-Temperature/Cryogenic Type is a model capable of measurement in high-temperature and cryogenic fluid. It is suitable for measuring high-temperature superheated steam used in applications such as food processing (including drying, heating, and sterilization), automotive and machinery components (rapid and uniform heating, oxidation prevention, and heating and cleaning processes), and measurement of cryogenic fluids such as liquefied natural gas (LNG).

Reduced Bore Type: Flow Tube Integrated with Reduction/Expansion Pipes

The Reduced Bore Type is a model in which both upstream and downstream sides of the sensor unit are integrated with a reducer (reduction/expansion pipe). It is ideal for saturated steam applications with large seasonal flow variations and for batch processes where flow measurement is required only when needed, and it also supports low flow rate measurement.
Because the reducer and the vortex flowmeter are integrated, reduction pipes, expansion pipes, and short pipes for securing straight pipe lengths are not required, which helps simplify installation work and reduce costs. Safety is improved because there are fewer connection points.

High-Pressure Type: Stable Measurement in Harsh High-Pressure Process Fluid

The High-Pressure Type is a model capable of stable measurement even under harsh high-pressure conditions. It is suitable for use in applications involving high-pressure gases and high-pressure steam that cannot be handled by standard models, such as natural gas transportation lines, high-pressure gas pipelines, high-pressure steam lines in oil refining and chemical plants, and high-pressure boilers.

Dual-Sensor Type: Provides redundancy for even higher reliability

The Dual-Sensor Type is a model in which two vortex flowmeter units are arranged in series and integrated into a single welded design. Since each unit measures the flow rate independently, the dual configuration provides redundancy for even higher reliability. In addition, the Dual-Sensor Type model can flexibly support operation in separate control and safety systems, as well as with different communication protocols. Its integrated welded design offers excellent installability and reduces the risk of fluid leakage by minimizing connection points. As a result, it improves the reliability of the system. The Long Neck Type suitable for thermal insulation workability is also available.

Long Neck Type: Suitable for Thermal Insulation Workability

The Long Neck Type is a model designed with a longer neck than standard vortex flowmeters. This type improves insulation such as in steam lines to prevent thermal energy loss from piping. It supports the General Type and Built-in Temperature Sensor Type.

Remote Type: Flexible Installation With a Separate Sensor and Transmitter

The Remote Type features a separate sensor and transmitter that can be installed by connecting them with a cable. It is suitable for applications where the transmitter needs to be installed in a safe location, such as in high-temperature or high-vibration lines, or in hazardous areas. The Remote Type is available for all types.

Total Insight － A Product Concept for Supporting Customers Throughout the Entire Product Lifecycle

Total Insight is a shared concept for Yokogawa’s field products that supports customers throughout the entire product lifecycle. By providing new value through superior technology and insight, it is aimed at optimizing costs over the entire lifecycle.

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Reduced Engineering Work Hours and Procurement Costs

Our vortex flowmeters support a wide flow range and conform to a variety of international standards. They also incorporate various built-in calculation functions and support various flow measurement needs.

Reduced Start-up Time

Yokogawa’s proprietary technology accurately captures flow signals, providing stable flow measurement with strong resistance to vibration.
In addition, device parameters are set at the factory before shipping, so the device is ready for use as soon as it is installed.

Improved Operational Efficiency and Reduced Errors

Total Insight features a self-diagnostic function for the entire device. With remote maintenance, the health of the device can be checked from a remote location, such as an instrument room. Furthermore, planned predictive maintenance (Condition-Based Maintenance: CBM) can be performed.^＊1  

*1: Requires the FSA130 Magnetic Flowmeter/Vortex Flowmeter Verification Tool (for HART Communication Only).

Improved Efficiency in Maintenance Operations

Anomalies can be easily identified using diagnostic functions. In addition, when removal of the vortex shedder bar is required, it can be easily detached from its uniquely structured body.

Recommended for the Following Users

• Those who want to purchase a flowmeter from a reliable manufacturer with a proven track record.
• Those who want to introduce flowmeters that offer excellent robustness and long-term stability and are easy to maintain.
• Those who are looking for flowmeters suitable for steam-related applications such as saturated steam, superheated steam, and batch processes.
• Those who want to improve energy efficiency, reduce costs, and manage CO2 emissions toward future smart factory development, and who are also looking to visualize the energy of utility fluids such as water, fuel, air, and steam.