Why are Vortex Flowmeter VY Series Ideal Steam Flowmeters? -The Consistently Optimal Flowmeter from Selection to Replacement-

Contents

 

1. Introduction

Steam is a high‑temperature, high‑pressure heat medium used across a wide range of industries. Steam is supplied throughout chemical plants and factories through steam lines and is used for numerous applications such as temperature control in reactors and equipment, sterilization, cleaning, and air conditioning. Steam energy consumption continues to grow, and with increasing expectations for energy savings and environmental awareness, the demand for steam flow measurement is also increasing.

To meet these demands, we propose Vortex Flowmeter VY Series as the ideal steam flowmeter. This article explains why and provides background on steam measurement.

 

2. Why Is the Demand for Steam Flow Measurement Increasing?

In recent years, further energy savings, operational efficiency, and realization of smart factories (DX) have become major themes in manufacturing. Furthermore, achieving the SDGs and realizing a carbon‑neutral society have become global challenges. As examples of DX and GX initiatives, visualization of equipment and process data is first carried out through the realization of DX to improve productivity and efficiency and to detect abnormalities.
By using these data to visualize carbon emissions—such as accurately measuring carbon footprints—the process then leads to the achievement of GX.

Within these initiatives, the first step in visualizing steam is measuring steam flow rate. This enables monitoring of energy consumption and fuel costs, leading to reduced energy losses and improved fuel efficiency. As a result, the demand for steam flowmeters is increasing.

 

 

3. What Are the Requirements for Steam Flowmeters?

Fig. 1 shows that steam flowmeters must meet diverse requirements. Steam line operation is long‑term and has seasonal and operational variability; thus long‑term stability and adaptability are required for steam flowmeters. Vortex Flowmeter VY Series has the features to meet these diverse requirements.

Fig. 1: Relationship between Steam Flowmeter Requirements and VY Series Features

 

4. Why Are the Vortex Flowmeter VY Series Ideal Steam Flowmeters?

This section introduces an example steam line system to show why the VY Series is optimal throughout its lifecycle, from selection to replacement. For the basics of vortex flow measurement, see the tutorial “Basics of Vortex Flowmeters: Measurement Principle and Measured Fluids.”

Figure 2 shows an example saturated steam line. The steam line consists of saturated steam package boilers with the following characteristics: maximum steam flow rate of 2,500 kg/h; saturated steam temperature of 170 ℃; and saturated steam pressure of 0.69 MPaG / 0.79 MPaA. These package boilers supply steam to all the production facilities with a maximum operating steam flow rate of 8,000 kg/h.
Steam is delivered from the boilers to the main steam header. Pressure reducing valves change steam pressure before reaching each facility. To efficiently monitor the entire steam line, seven the VY Series (A–G) are installed at the supply side of the steam header and at the demand side of steam-using facilities, the large heating unit, the heating unit, and the heat exchanger.
Table 1 shows the pipe diameters, steam flow rates, temperatures, and pressures at the installation points of the VY Series.

Fig. 2: Example of Steam Line

 

Table 1: Conditions at Each Installation Point

The Vortex Flowmeter VY Series No.	Pipe Conditions	Normal Temp. (℃)	Max Temp. (℃)	Normal Press. (MPaA)	Minimum Press. (MPaA)	Normal Flow Rate (kg/h)	Minimum Flow Rate (kg/h)	Max Flow Rate (kg/h)
A : Outlet of Boiler	DN100 Sch80 JIS 10K	170	190	0.792	0.5	2500	1000	8000
B : Inlet of Large Heating Unit 1	DN80 Sch80 JIS 10K	170	190	0.792	0.5	500	350	4000
C : Inlet of Heating Unit 2	DN80 Sch80 JIS 10K	150	170	0.476	0.3	500	180	1000
D : Inlet of Heating Unit 3	DN80 Sch80 JIS 10K	150	170	0.476	0.3	500	160	1000
E : Inlet of Heating Unit 4	DN80 Sch80 JIS 10K	150	170	0.476	0.3	500	150	1000
F : Inlet of Heating Exchanger 1	DN50 Sch40 JIS 10K	130	150	0.270	0.2	350	100	700
G : Inlet of Heating Exchanger 2	DN50 Sch40 JIS 10K	130	150	0.270	0.2	150	60	300

 

4.1. Selection

Table 1 shows the conditions that determine sizing, such as flow rate, temperature, pressure, and pipe conditions. For more details, see “General Specifications.” The VY Series offers a wide range of explosion‑proof certifications, pipe connection standards, reducer types, and optional specifications, enabling optimal specification selection for various customer environments and requirements.

Table 2 shows sizing and specification selection results for this example. The built‑in temperature sensor type uses an internal saturated steam table to calculate steam density and output steam mass flow. The communication type is HART, and model code and optional specifications are assigned based on installation conditions.

The VY Series also measures superheated steam up to 450℃ and 40 MPa. The external input specification (analog input function) can calculate accurate superheated steam density and mass flowrate by built-in temperature sensor and external pressure sensor value. The built-in temperature type has standard connection sizes from 25 mm to 300 mm (400 mm available as custom).
For more detail, see “Vortex Flowmeter VY Series.”

 

Table 2: Selection Results Example for the VY Series

The Vortex Flowmeter VY Series No.	Reason of Specification Selection	Selection MS Code of the VY Series
A : Outlet of Boiler	Line Size DN100, Bulit-in Temp. Sensor Type, Long Neck Type, JIS 10K Flange Type, HART Communication Type, With Arrester, With Stainless Tag Plate Selected Long Neck Type for easier insulation work Added arrester for outdoor install: /A Add stainless steel tag Plate for maintenance: /SCT	VY100-000-0HBLBBJ1-10JA100/A/SCT
B : Inlet of Large Heating Unit 1	Line Size DN80, Bulit-in Temp. Sensor Type, JIS 10K Flange Type, Remote Type, HART Communication Type, With Stainless Tag Plate Piping is located near the roof: Remote Type Add stainless steel tag Plate for maintenance: /SCT	VY080-000-0BBLBBJ1-10NNN00/SCT VY4A-000-10JA100/PJ/SCT VY1C-1-10M
C : Inlet of Heating Unit 2	Line Size DN80, Bulit-in Temp. Sensor Type, JIS 10K Flange Type, HART Communication Type, With Stainless Tag Plate Add stainless steel tag Plate for maintenance: /SCT Note: Reducer type may also be selected because sizing requirements can be satisfied.	VY080-000-0BBLBBJ1-10JA100/SCT
D : Inlet of Heating Unit 3		VY080-000-0BBLBBJ1-10JA100/SCT
E : Inlet of Heating Unit 4		VY080-000-0BBLBBJ1-10JA100/SCT
F : Inlet of Heating Exchanger 1	Line Size DN50, Bulit-in Temp. Sensor Type, JIS 10K Flange Type, HART Communication Type, With Stainless Tag Plate, Cable Entry Direction Change Add stainless steel tag Plate for maintenance: /SCT Change display direction not to face the wall: /RH	VY050-000-0BBLBBJ1-10JA100/SCT/RH
G : Inlet of Heating Exchanger 2	Line Size DN50, Reducer Type, Bulit-in Temp. Sensor Type, JIS 10K Flange Type, HART Communication Type, With Stainless Tag Plate Selected Reducer Type because normal and minimum flow rates are low; Connection Size: (000)-1(BBL) Add stainless steel tag Plate for maintenance: /SCT	VY050-000-1BBLBBJ1-10JA100/SCT

 

4.2. Installation and Wiring

The VY Series supports various flange and wafer types of connection standards and can be installed horizontally, vertically, or on inclined pipes. In addition, it has short face‑to‑face dimensions and a short required straight pipe run compared with other vortex flowmeters. There are also fewer installation restrictions related to thermal conditions.
For more detail on straight pipe lengths, see the tutorial page “Required Straight Pipe Lengths for Vortex Flowmeters.”

Because vortex flowmeters are two‑wire flowmeters, wiring is simpler than four‑wire types. Additionally, zero‑adjustment is unnecessary; measurement begins immediately when powered on.

When installing a steam flowmeter, insulation work is important to prevent thermal energy loss from piping. The VY Series long‑neck type improves insulation work on steam lines.

Fig. 3: Excellent Ease of Installation of the VY Series

 

4.3. Startup

The built‑in temperature sensor type can also measure steam temperature during boiler preheating, reducing instrumentation costs. Additionally, a built‑in temperature sensor measures fluid temperature near the pipe center, reducing heat loss from piping and the drain effect.

When you check whether steam flow measurement is stable and accurate in the startup process, Vortex Waveform Monitor (available through FieldMate and FSA130 Magnetic Flowmeter/Vortex Flowmeter Verification Tool, sold separately) enable monitoring of vortex waveforms and pulse signals. Stable vortex generation is essential for vortex flowmeters (see the tutorial “Basics of Vortex Flowmeters: Measurement Principle and Measured Fluids”).
Vortex Waveform Monitor collects the vortex waveforms detected by the sensor and the pulse waveforms to calculate the vortex frequency and displays them on the screen. If the vortex waveform becomes a regular sine wave and the pulse waveform becomes regular, steam flow measurement is stable and accurate. Using Vortex Waveform Monitor, you can visually confirm whether steam flow measurement is stable during startup. You can also adjust the VY Series parameters as needed while viewing the vortex waveform and pulse (Fig. 5). These methods allow confirmation of accurate measurements without an oscilloscope.

Fig. 5: Use of Vortex Waveform Monitor During Startup

 

4.4. Operation

The sensing structure of the VY Series has outstanding reliability and long-term stability, proven by sales records over many decades. Yokogawa launched the world's first vortex flowmeter in 1969 and launched the general-purpose vortex flowmeter YEWFLO series in 1979. For over 50 years, to meet various requirements and support applications of our customers, the YEWFLO series has continuously evolved. Vortex Flowmeter VY Series is the latest model of the YEWFLO series (Fig .6).

Fig. 6: History of Yokogawa Vortex Flowmeters

The VY Series can accurately measure the steam flow rate despite seasonal variations, load fluctuations, and steam flow rate changes because it has wide rangeability of flow rate and temperature. Even when a rapid temperature drop causes a drain effect and a decrease in steam quality, Yokogawa’s unique sensing structure accurately captures the Kármán vortices and accurately measures the flow rate with minimal interference.

Because vortex flowmeters cause pressure loss, this factor should be considered to decrease energy loss during operation. The temperature decrease due to the pressure loss of the VY Series is below 0.5℃ at the normal operating flow rate in this example (Table 3). Note that pressure loss varies depending on the beta ratio and other conditions, but the VY Series has approximately 50% to 80% lower pressure loss compared with orifice flowmeters, thereby decreasing energy loss during operation.

 

Table 3: Example of Pressure Loss by the VY Series

The Vortex Flowmeter VY Series No.​	VY​Specification​	Normal​Temp.​(℃)​	Normal​Press.​(MPaG)​	Press. Loss in Normal Flow Rate ​(kPa)​	Temp. Reductions by Press. Loss​(℃)​	Normal Flow Rate​(kg/h)​	Press. Loss in Max​Flow​Rate ​(kPa)​	Temp. Reductions by Press. Loss​(℃)​	Max​Flow​Rate​(kg/h)​
A : Outlet of Boiler	VY100​	170​	0.691​	8.45​	0.4​	2500​	27.0​	1.4​	8000​
B : Inlet of Large Heating Unit 1	VY080​	170​	0.691​	2.57​	0.1​	500​	20.6​	1.1​	4000​
C : Inlet of Heating Unit 2	VY080​	150​	0.374​	1.04​	0.1​	500​	2.1​	0.2​	1000​
D : Inlet of Heating Unit 3	VY080​	150​	0.374​	1.04​	0.1​	500​	2.1​	0.2​	1000​
E : Inlet of Heating Unit 4	VY080​	150​	0.374​	1.04​	0.1​	500​	2.1​	0.2​	1000​
F : Inlet of Heating Exchanger 1	VY050​	130​	0.169​	3.24​	0.4​	350​	6.5​	0.8​	700​
G : Inlet of Heating Exchanger 2	VY050 -1​Reducer Type​	130​	0.169​	1.87​	0.2​	150​	3.7​	0.5​	300​

 

4.5. Maintenance

The VY Series requires minimal maintenance under suitable conditions. Moreover, it also provides advanced digital diagnostic capabilities to realize Condition-Based Maintenance (CBM). 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.
When combined with FieldMate, FSA130 Magnetic Flowmeter, and Vortex Flowmeter Verification Tool (sold separately), it provides verification functions for checking and reporting the status of sensors, signal processing, alarms, and other parameters. It also provides remote maintenance functions for Vortex Waveform Monitor, Vortex Frequency Analyzer, and Vortex Sensor Prediction Health Check (Fig. 7).
For more details, see “FSA130 Magnetic Flowmeter and Vortex Flowmeter Verification Tool.”

Fig. 7: Diagnostic Functions of the VY Series

 

 

4.6. Replacement

The VY Series has the same face‑to‑face dimensions as all YEWFLO models since Style D launched in 1987. Thus, you can replace existing YEWFLO Series with the VY Series without piping modification even when you need to change specifications (Fig. 9). For more about replacement, see “Upgrading Existing Steam Facilities: Introducing Vortex Flowmeter VY Series.”

Fig. 9: Advantages of Replacing Previous Models

 

 

5. Conclusion

This article explained why the Vortex Flowmeter VY Series are ideal steam flowmeters. Their ability meets many requirements consistently from selection to replacement. The VY Series offers a wide range of specifications and features. Please refer to the product page for more details.

We hope this article helps you understand steam flowmeters, steam measurements, and how the VY Series contribute not only to improving productivity but also to realizing DX and GX.