와류 유량계 VY

Features of the VY Series

Using Digital Technology to Help Improve Efficiency and Manpower-saving Maintenance Activities

Plants with many pieces of device in operation require “Condition-Based Maintenance (CBM),” which is efficient and systematic predictive maintenance based on the condition of the device. The VY series is equipped with a "self-diagnostic function (built-in verification)" for the entire device, including the vortex shedder bar with sensor elements, and a "process diagnostic function" that detects pulsation and fluctuation of the measured fluid and piping vibration based on the characteristics of the measured signals, through advanced digitization of the internal signals.　In combination with the FSA130 Magnetic Flowmeter and Vortex Flowmeter Verification Tool (sold separately) and FieldMate which is adjustment, configuration, and management software (sold separately), those provides "verification functions" and "remote maintenance functions". These functions can be easily used on a PC screen in an instrument room away from the site, dramatically improving the checking and management of device health and operating conditions. In this way, the VY series promotes efficiency and manpower savings in maintenance activities and supports efficient plant operation.

*For more details on the FSA130 Magnetic Flowmeter and Vortex Flowmeter Verification Tool, click here

Unique Structure and Technology to Reduce Downtime for Maintenance and Stabilize Flow Measurement

The VY series inherits the high reliability and proven original sensing structure of the previous YEWFLO series. The vortex shedder bar has a unique sensing structure that incorporates two flow sensors and one temperature sensor (optional) and can be detached from the body. This structure not only results in robustness, long-term stability, short face-to face length, and short upstream straight pipe length, but also allows cleaning and replacement of the vortex shedder bar without removing the entire flowmeter from the piping when maintenance is required due to fluid deposition and other factors. This helps minimize the downtime required for maintenance. In addition, our unique digital signal processing technology effectively eliminates piping vibration, resulting in stable measurement. Mechanically and functionally compatible with successive generations of the YEWFLO series, the VY series can be installed in the same locations without the need for any additional piping work.

The VY series facilitates efficiency and labor savings in maintenance operations, supporting efficient plant operations.

Product Lineup

VY Series Common Specifications

Vortex Flowmeter VY Series can measure the flow rates of liquids, gases, saturated steam, and superheated steam, and has self-diagnostic and remote maintenance functions. A choice of materials is available for the wetted parts, stainless steel including duplex stainless steel or nickel alloys. The series complies with a wide range of standards, including explosion-proof and SIL2. The current input function (HART7, when current input specification is selected) supports more accurate calculation capabilities* than ever before, including mass flow rate and energy flow rate of liquids, gases, and steam.
＊Saturated and superheated steam tables built in

[Common Specification]

Refer to the General Specification sheet located under the Downloads tab for detailed specifications.

General Type

The general type is the basic model of the VY series.
The lineup includes connection size from 15 to 400 mm, process temperatures from -40°C to 250°C, and process pressures up to ASME Class 900.

[Specific Specification of General Type]

Refer to the General Specification sheet located under the Downloads tab for detailed specifications.

Built-in Temperature Sensor Type

The built-in temperature sensor type has a temperature sensor (Pt1000) built into the shedder bar (vortex generator), allowing simultaneous measurement of the process fluid temperature.
These flowmeters are compatible with connection size from 25 to 300 mm, and can also be used in conjunction with high-temperature type and reduced bore type models, allowing them to handle a wide range of fluids. Compensation calculations are performed at temperatures close to that at the center of the pipe, enabling more accurate measurement of flow rates. Signals from an external pressure gauge can be captured and used in compensation calculations with the current input function (when HART7 communication and current input specifications are selected) to support even more accurate flow measurement.

[Specific Specification of Built-in Temperature Sensor Type]

Refer to the General Specification sheet located under the Downloads tab for detailed specifications.

High-Temperature / Cryogenic Type

The high-temperature and cryogenic models use the materials and sensors required for high-temperature and extremely low-temperature environments.
The high-temperature type handles connection size from 25 to 400 mm and fluid temperatures up to 450°C (up to 400°C with a built-in temperature sensor). The cryogenic type handles connection size from 15 to 100 mm and fluid temperatures of as low as -196°C. From this model, It is possible to select either type as an integral type or remote type.

[Specific Specification of High Temperature Type]

[Specific Specification of Cryogenic Type]

Refer to the General Specification sheet located under the Downloads tab for detailed specifications.

Reduced Bore Type (1 or 2 Size Reduction)

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). As such, it is ideal for lines where flow rates fluctuate widely depending on the season and operating load.
The reduced bore type are available in two types, one-size reduction and two-size reduction, and the flange model accommodates connection size of up to 200 mm. The reduced bore type can be combined with the built-in temperature sensor type and the high-temperature/cryogenic type, allowing measurement of a wide range of fluids.

[Specific Specification of Reduced Bore Type (1 or 2 Size Reduction)]

Refer to the General Specification sheet located under the Downloads tab for detailed specifications.

High-Pressure Type

This is a one-size reduction model with an ASME Class 1500 flange pressure rating. This allows it to provide stable measurement even under harsh high-pressure conditions.
In combination with a general-type sensor, it uses a flange-type connection size 25 to 150 mm.

[Specific Specification of High Pressure Type]

Refer to the General Specification sheet located under the Downloads tab for detailed specifications.

Dual-Sensor Type

This type is dual-sensor (welded) type that has a flange pressure rating of up to ASME Class 900. The structure of these two units connected in series is the best choice for applications requiring high reliability.
Size is from 15 mm to 200 mm in combination with several types of sensor.

[Specific Specification of Dual-Sensor Type]

* Type of shedder bar is same as upstream and downstream
* Refer to the General Specification sheet located under the Downloads tab for detailed specifications.

Examples of VY Series Applications

• Flow measurement in steam piping
• Flow measurement of utility gases such as air and nitrogen
• Flow measurement of hot and cold water, LNG and other cryogenic liquids and chemicals (including inorganic substances)

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

From Sensing to Sensemaking

• Simplified Selection : Reduced engineering work hours and procurement costs
• Smart Assist : Reduced start-up time
• Process Guard : Improved operational efficiency and reduced errors
• Expert Solution : Improved efficiency in maintenance operations

Reduced Engineering Work Hours and Procurement Costs / Total Insight - Simplified Selection -

A Comprehensive Lineup to Meet Various Flow Measurement Needs

• Easy Device Selection
  A wide range of flow sizes, up to 400 mm, can be accommodated. The reduced bore type allows reductions of up to two sizes. With the same face-to face dimensions as successive generations of the YEWFLO series, they can be used safely and reliably for long periods of time.

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Reduced Start-up Time / Total Insight - Smart Assist -

Provides Stable Flow Measurement Resistant to Vibration

• Ready to Use as Soon as Installed
  Device parameters are set at the factory before shipping. The automatic adjustment function provided by SSP basically eliminates the need for on-site adjustment. This means that the devices are ready for use as soon as they are installed. Verification tools, including waveform monitoring, make it easy to check status after installation.

Improved Operational Efficiency and Reduced Errors / Total Insight - Process Guard -

Advanced Self-Diagnostics and Remote Maintenance

• Self-Diagnosis of the Entire Device Can Be Performed
  All functional blocks are self-diagnosing, allowing easy identification of areas requiring equipment maintenance. Since it conforms to the functional safety SIL2 standard requirements, it can be used in loops that require high reliability, such as safety instrumentation.

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Improved Efficiency in Maintenance Operations / Total Insight - Expert Solution -

Various Functions to Support Efficient Maintenance Operations

Technical Information - Measurement principle -

Vortex flowmeters use the Von Karman Effect to measure the flow rate of liquids, gases, and steam. This section explains the principle.

The Operating Principle of Vortex Flowmeters

• What Is a Von Karman Vortex?
  In the early 20th century, the Hungarian-born mathematician and physicist Theodore von Karman discovered that when a liquid or gas flows perpendicular to an obstacle, it creates alternating vortices on either side of that obstacle. These rows of vortices are called “Von Karman vortex streets.”

Von Karman further found that the number of vortices generated is proportional to the velocity of the fluid that generates them. This number of vortices generated is called the “Von Karman vortex frequency.” The relationship between the frequency and the flow velocity can be mathematically expressed with the following formula (1). Formula (2) further expresses the relationship with the internal structure of a vortex flowmeter. Putting these two formulas together and expressing them in terms of volumetric flow rate yields formula (3).

f: Von Karman vortex frequency, St: Strouhal number, v: flow velocity, d: width of vortex generator, Q: volumetric flow rate, D: inner diameter of vortex flow meter

The Strouhal number (St) is a dimensionless number determined by the shape and dimensions of the vortex shedder bar, and by properly choosing the shedder bar’s shape, it becomes constant over a wide range of Reynolds number values. Figure 1 shows the relationship between the Reynolds number and the Strouhal number.

Relationship between Reynolds number and Strouhal number (St)

Therefore, if the Strouhal number is known in advance, the flow rate can be determined by measuring the vortex frequency. It has also been found that the volumetric flow rate can be measured irrespective of the pressure, temperature, density, viscosity, etc. of the fluid. However, when measuring volumetric flow or mass flow under standard (reference) conditions, temperature and pressure corrections are required.

• How Is Vortex Frequency Measured?
  When vortices form and pass through a vortex shedder bar (obstacle), the pressure in that area is lower than that in the rest of the fluid. This low pressure creates a pressure differential (dp) on each side of the vortex shedder bar, and stress is applied to the vortex shedder bar from the high-pressure side toward the low-pressure side. The position where the vortices are generated switches regularly, causing the position of the low-pressure area to change and the direction of the stress to shift, causing the vortex shedder bar to oscillate. The frequency of this oscillation is the Von Karman vortex frequency.

The vortices generated create low-pressure and high-pressure areas on both sides of the vortex shedder bar, and force is exerted toward the low-pressure area. As the position of the vortices change from one side to the other, the direction of this force is switched, causing the vortex shedder bar to oscillate.

Several methods are available as means of measuring this oscillation. The most suitable for this application is the piezoelectric crystal sensor. When compressed, the piezoelectric crystal sensor produces an electrical signal that is processed by the flowmeter’s electronics. By measuring the Von Karman vortex frequency (the Strouhal number and the diameter of the cylinder are known), a simple calculation by the flowmeter’s electronics can determine the rate of volumetric flow through the pipe.

Technical Information - Our Proprietary Signal Processing Technology -

Vortex flowmeters using Von Karman vortices are vibration sensors that count vortex frequencies, and as such, they are susceptible to external vibration noise. However, the VY series uses Yokogawa’s proprietary signal processing technology to ensure stable measurements at all times. Here is how it works.

Noise Reduction

As with previous models, the VY series of vortex flowmeters incorporates Yokogawa’s proprietary signal processing technology, SSP. SSP performs frequency analysis of the signal detected from the vortex shedder bar, divides it into separate bands, and automatically selects the optimal bandpass filter to transmit only the correct vortex signal with the noise removed. Even if the vortex signal contains vibration noise, only the vortex signal is output, thus ensuring stable measurement.

Noise from strong piping vibration can affect the accuracy of vortex frequency detection, but the two piezoelectric elements in the VY series have reversed polarity, and therefore do not detect vibrations in the flow direction or the perpendicular direction. Noise in the direction of lift is reduced, allowing only the vortex signal to be detected. With superior vibration resistance and diagnostic functions based on our proprietary technology, the VY series provides stable measurements at all times.

Technical Information - Required Straight Pipe Lengths for Different Installation Conditions -

In general, unbalanced velocity distribution in a pipe affects the accuracy of flow measurement in vortex flowmeters. Shown below are the required straight pipe lengths and key points to consider, along with typical installation examples.

Technical Information - Mounting Orientation -

The mounting can be horizontal, vertical, or inclined, as long as the pipe is always filled with fluid. However, when installing on horizontal or inclined piping, be sure to mount above the pipe to avoid flooding of the terminal box of separated detectors or the transmitter of integrated models. This is illustrated in the diagrams below.

Horizontal Piping

Vertical Piping

Inclined Piping