CST-VXW Vortex Flow Meter for Steam, Gas and Liquid

CST-VXW vortex flow meter for steam and gas

The CST-VXW vortex flow meter accurately measures saturated steam, superheated steam, compressed air, gases and liquids on a single instrument platform. Based on the Kármán vortex-shedding principle with no moving parts, it offers ±1.0 % accuracy, process temperatures up to 350 °C, pressures up to 4.0 MPa, 4–20 mA + pulse output and HART or RS485 Modbus communication. Versions with integrated temperature and pressure compensation give direct mass flow (kg/h, t/h) – the leading solution for boiler steam flow measurement.

Equipment Industrial Solution Co., Ltd (ISE) supplies the CST-VXW from DN15 to DN2000, sizes the meter to your actual flow, and supports configuration and PLC/SCADA integration.

How does a vortex flow meter work?

A triangular bluff body (vortex generator) is placed across the flow inside the meter body. As the fluid passes, vortices are shed alternately from each side – the Kármán vortex street. The shedding frequency is linearly proportional to flow velocity. The sensor detects this frequency and the electronics convert it to a standard flow signal. With no rotating or wearing parts, vortex meters are stable over the long term, need little maintenance and withstand high-temperature steam lines and pipe vibration.

Advantages of the CST-VXW vortex flowmeter

  • Measures steam, gas and liquids: saturated and superheated steam, compressed air, natural gas, water, light oils…
  • No moving parts – no jamming or wear, virtually maintenance-free.
  • Accuracy ±1.0 % (flanged / wafer), ±1.5 % (insertion).
  • Integrated temperature and pressure compensation: direct steam mass flow (kg/h) or normalised gas flow (Nm³/h) without an external flow computer.
  • Wide velocity range: liquids 0.4–7 m/s, gases 4–60 m/s, steam 5–70 m/s.
  • High temperature: −40 °C to +250 °C standard, up to +350 °C high-temperature version; pressure 0.6 – 4.0 MPa.
  • Flexible outputs: 4–20 mA + pulse, HART or RS485 Modbus for PLC, DCS and SCADA.
  • 12–30 VDC supply or 3.6 V lithium battery for locations without power.
  • ATEX Ex ia IIC T5 Ga approval; SS304 wetted parts, SS316 optional.

Connection types and configurations

  • Flanged (DN15–DN300): fixed pipeline installation, DIN PN16 flanges (other standards on request).
  • Wafer (DN15–DN300): clamped between existing flanges – compact and cost-effective.
  • Insertion (DN80–DN2000): for large pipes, installed without cutting the pipe.
  • Threaded / sanitary (DN15–DN100): threaded or tri-clamp connections for food and pharmaceutical lines.
  • Compact or remote display with temperature/pressure compensation for saturated and superheated steam.

Applications: steam, compressed air and liquid flow

  • Boiler steam flow (saturated and superheated): boiler efficiency monitoring, steam distribution and energy allocation per department.
  • Compressed air, fuel gas and process gas flow in factories and gas stations.
  • Oil & gas, petrochemical and chemical process gases and liquids (SS316 option for corrosion resistance).
  • Energy management: steam, compressed air, hot/chilled water for HVAC and utilities.
  • Food, beverage and pharmaceutical lines with sanitary connections.
  • Water supply and wastewater; metallurgy and cement high-temperature gases and steam.

CST-VXW vortex flow meter specifications

Parameter Value
Media Liquid, gas, steam
Process temperature −40 °C to +250 °C (standard); −40 °C to +350 °C (high-temperature)
Nominal pressure 0.6 / 1.0 / 1.6 / 2.5 / 4.0 MPa
Accuracy ±1.0 % (flanged / wafer); ±1.5 % (insertion)
Velocity range Liquid 0.4–7.0 m/s; gas 4.0–60.0 m/s; steam 5.0–70.0 m/s
Sizes DN15–DN300 (flanged / wafer); DN80–DN2000 (insertion); DN15–DN100 (threaded / sanitary)
Wetted material SS304 (standard); SS316 (optional)
Reynolds number 2×10⁴ – 7×10⁶
Pressure loss coefficient (Cd) ≤ 2.6
Allowable vibration ≤ 0.2 g
Explosion protection ATEX Ex ia IIC T5 Ga
Ambient temperature −40 °C to +65 °C (safe area); −20 °C to +55 °C (hazardous area)
Relative humidity ≤ 85 %
Atmospheric pressure 86–106 kPa
Power supply 12–30 VDC or 3.6 V lithium battery
Output 4–20 mA, pulse
Communication RS485 (Modbus) or HART

Liquid and gas flow ranges by pipe size

Reference flow ranges for flanged and wafer types (DN15–DN300). Insertion types DN80–DN2000 are calculated for actual installation conditions.

Size DN (mm) Liquid (m³/h) Air / Gas (m³/h)
Standard range Extended range Standard range Extended range
15 0.8–6 0.5–8 6–40 5–50
20 1–8 0.5–12 8–50 6–60
25 1.5–12 0.8–16 10–80 8–120
32 2–20 1.5–25 15–150 10–200
40 2.5–30 2–40 25–200 20–300
50 3–50 2.5–60 30–300 25–500
65 5–80 4–100 50–500 40–800
80 8–120 6–160 80–800 60–1200
100 12–200 8–250 120–1200 100–2000
125 20–300 12–400 160–1600 150–3000
150 30–400 18–600 250–2500 200–4000
200 50–800 30–1200 400–4000 350–8000
250 80–1200 40–1600 600–6000 500–12000
300 100–1600 60–2500 1000–10000 600–16000

Saturated steam flow table (kg/h)

Minimum (Qmin) and maximum (Qmax) mass flow by pipe size and absolute pressure of saturated steam – use this table to size a steam flow meter for your boiler.

Absolute pressure 0.2 – 0.8 MPa

Absolute pressure (MPa) 0.2 0.3 0.4 0.5 0.6 0.7 0.8
Temperature (°C) 120.2 133.5 143.62 151.84 158.94 164.96 170.41
Density (kg/m³) 1.129 1.651 2.163 2.669 3.17 3.667 4.162
15 Qmin 5.645 8.255 10.815 13.345 15.85 18.335 20.81
Qmax 56.45 82.55 108.15 133.45 158.5 183.35 208.1
20 Qmin 6.774 9.906 12.978 16.014 19.02 22.002 24.972
Qmax 67.74 99.06 129.78 160.14 190.2 220.02 249.72
25 Qmin 9.032 13.208 17.304 21.352 25.36 29.336 33.296
Qmax 135.48 198.12 259.56 320.28 380.4 440.04 499.44
32 Qmin 20.322 29.718 38.934 48.042 57.06 66.006 74.916
Qmax 203.22 297.18 389.34 480.42 570.6 660.06 749.16
40 Qmin 22.58 33.02 43.26 53.38 63.4 73.34 83.24
Qmax 338.7 495.3 648.9 800.7 951 1100.1 1248.6
50 Qmin 28.225 41.275 54.075 66.725 79.25 91.675 104.05
Qmax 564.5 825.5 1081.5 1334.5 1585 1833.5 2081
65 Qmin 45.16 66.04 86.52 106.76 126.8 146.68 166.48
Qmax 903.2 1320.8 1730.4 2135.2 2536 2933.6 3329.6
80 Qmin 67.74 99.06 129.78 160.14 190.2 220.02 249.72
Qmax 1354.8 1981.2 2595.6 3202.8 3804 4400.4 4994.4
100 Qmin 112.9 165.1 216.3 266.9 317 366.7 416.2
Qmax 2258 3302 4326 5338 6340 7334 8324
125 Qmin 169.35 247.65 324.45 400.35 475.5 550.05 624.3
Qmax 3387 4953 6489 8007 9510 11001 12486
150 Qmin 225.8 330.2 432.6 533.8 634 733.4 832.4
Qmax 4516 6604 8652 10676 12680 14668 16648
200 Qmin 395.15 577.85 757.05 934.15 1109.5 1283.45 1456.7
Qmax 9032 13208 17304 21352 25360 29336 33296
250 Qmin 564.5 825.5 1081.5 1334.5 1585 1833.5 2081
Qmax 13548 19812 25956 32028 38040 44004 49944
300 Qmin 677.4 990.6 1297.8 1601.4 1902 2200.2 2497.2
Qmax 18064 26416 34608 42704 50720 58672 66592

Absolute pressure 0.9 – 2.0 MPa

Absolute pressure (MPa) 0.9 1.0 1.2 1.4 1.6 1.8 2.0
Temperature (°C) 175.36 179.68 187.96 195.04 201.37 207.11 212.37
Density (kg/m³) 4.665 5.147 6.127 7.106 8.085 9.065 10.05
15 Qmin 23.325 25.735 30.635 35.53 40.425 45.325 50.25
Qmax 233.25 257.35 306.35 355.3 404.25 453.25 502.5
20 Qmin 27.99 30.882 36.762 42.636 48.51 54.39 60.3
Qmax 279.9 308.82 367.62 426.36 485.1 543.9 603
25 Qmin 37.32 41.176 49.016 56.848 64.68 72.52 80.4
Qmax 559.8 617.64 735.24 852.72 970.2 1087.8 1206
32 Qmin 83.97 92.646 110.286 127.908 145.53 163.17 180.9
Qmax 839.7 926.46 1102.86 1279.08 1455.3 1631.7 1809
40 Qmin 93.3 102.94 122.54 142.12 161.7 181.3 201
Qmax 1399.5 1544.1 1838.1 2131.8 2425.5 2719.5 3015
50 Qmin 116.625 128.675 153.175 177.65 202.125 226.625 251.25
Qmax 2332.5 2573.5 3063.5 3553 4042.5 4532.5 5025
65 Qmin 186.6 205.88 245.08 284.24 323.4 362.6 402
Qmax 3732 4117.6 4901.6 5684.8 6468 7252 8040
80 Qmin 279.9 308.82 367.62 426.36 485.1 543.9 603
Qmax 5598 6176.4 7352.4 8527.2 9702 10878 12060
100 Qmin 466.5 514.7 612.7 710.6 808.5 906.5 1005
Qmax 9330 10294 12254 14212 16170 18130 20100
125 Qmin 699.75 772.05 919.05 1065.9 1212.75 1359.75 1507.5
Qmax 13995 15441 18381 21318 24255 27195 30150
150 Qmin 933 1029.4 1225.4 1421.2 1617 1813 2010
Qmax 18660 20588 24508 28424 32340 36260 40200
200 Qmin 1632.75 1801.45 2144.45 2487.1 2829.75 3172.75 3517.5
Qmax 37320 41176 49016 56848 64680 72520 80400
250 Qmin 2332.5 2573.5 3063.5 3553 4042.5 4532.5 5025
Qmax 55980 61764 73524 85272 97020 108780 120600
300 Qmin 2799 3088.2 3676.2 4263.6 4851 5439 6030
Qmax 74640 82352 98032 113696 129360 145040 160800

Note: pressures are absolute (gauge pressure + approx. 0.1 MPa).

Installation dimensions – DIN PN16 flanged type

Size (DN) L (mm) H (mm) d (mm) D1 (mm) D2 (mm) n-D3
15 170 440 15 65 95 4-φ14
20 170 445 20 75 105 4-φ14
25 170 450 26 85 115 4-φ14
32 170 462 32 100 140 4-φ18
40 190 465 38 110 150 4-φ18
50 190 473 48 125 165 4-φ18
65 220 487 62 145 185 4-φ18
80 220 500 73 160 200 8-φ18
100 240 533 95 180 220 8-φ18
125 260 560 118 210 250 8-φ18
150 280 608 140 240 285 8-φ22
200 300 640 200 295 340 12-φ22
250 360 705 250 355 405 12-φ26
300 400 752 300 410 460 12-φ26

Dimensions in mm for DIN PN16 flanged type; wafer, insertion and other flange standards on request.

FAQ

Can a vortex meter measure boiler steam flow?

Yes – this is the most common vortex application. Choose a version with temperature and pressure compensation to read steam flow directly in kg/h or t/h.

How do I size a vortex flow meter?

Size it by actual flow and operating pressure, not necessarily by pipe size. For example, saturated steam at 0.8 MPa absolute (about 7 barg) and 1–2 t/h usually suits DN50 or DN65 (see the steam table above). Send us your data and ISE will size it for you.

How does a vortex meter differ from an electromagnetic flow meter?

Magnetic flow meters measure only conductive liquids. Vortex meters measure steam, gas and liquids (including non-conductive) at higher temperatures – but need sufficient velocity and straight pipe runs upstream and downstream.

What information is needed for a quotation?

Medium, min–max flow, operating pressure and temperature, pipe size, connection type, power supply and required output.

Related products

Where to buy the CST-VXW vortex flow meter?

EQUIPMENT INDUSTRIAL SOLUTION CO., LTD (ISE) – Ho Chi Minh City, Vietnam – supplies genuine the CST-VXW vortex flow meter with technical consulting, fast quotation and on-site commissioning support across Vietnam and Southeast Asia.

Contact us: Sales +84 909 617 185 – Technical +84 979 117 185 – Email: [email protected]

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