Vortex Flow Meters — Steam, Gas & Utility Flow Measurement for Modern Plants
Powered by NPK Industries & Co. – India’s Complete Process Instrumentation Partner
Accurate measurement of steam, compressed air, natural gas, nitrogen, hot water, and process liquids is essential for plant efficiency, energy management and production consistency. Vortex Flow Meters have become the industry standard for utility flow measurement, thanks to their ruggedness, low maintenance and outstanding performance in harsh environments.
NPK Industries supplies and integrates global technologies like:
Krohne Marshall Optiswirl 4200
Schneider Electric Foxboro 84CF Series
What is a Vortex Flow Meter?
A Vortex flow meter measures flow by placing a bluff body (a shedder bar) in the path of the fluid. As the fluid passes this obstruction, it creates alternating vortices — known as the Von Kármán vortex street.
Each vortex generates a pressure fluctuation, which is sensed by a piezo or capacitive sensor.
Frequency of vortex shedding ∝ Flow velocity
Thus:
Higher flow → more vortices → higher frequency → higher reading
Mathematically:
f = St × V / d
Where:
- f = vortex frequency
- St = Strouhal Number (constant)
- V = fluid velocity
- d = bluff body width
Working Principle
How It Works
- Fluid hits the bluff body
- Alternating vortices form
- Sensor detects oscillation frequency
- Microprocessor converts it to:
- Volumetric flow
- Mass flow (with T/P compensation)
- Energy (steam calculator models)
- Shedder bar (bluff body)
- Piezoelectric sensor
- RTD (optional)
- Pressure module (optional – Optiswirl 4200)
- Electronics + HART communication
When to Use Vortex Meters vs When Not To
Use Vortex When:
Do NOT Use Vortex When:
- Medium is steam, gas or clean liquid
- You need low-maintenance measurement
- Accuracy 1–2% is acceptable
- High temperature (up to 400°C)
- High pressure lines
- Energy monitoring is required
- Very low flow rates
- Very viscous fluids
- Slurry or fluids with suspended solids
- Two-phase flow (steam + water mix)
Industries & Plant Use-Cases
Dairy
Food & Beverage
Chemical & Petrochemical
Power Plant & Utilities
Water Treatment & General Industry
