Stationary Clamp-on Steam Measurement

The World‘s Only Clamp-On Steam Meter: FLUXUS ST

With FLUXUS ST, clamp-on steam measurement is now available for the very first time – as FLEXIM continues to push the boundaries and to set the standards.

Non-invasive and efficient

FLUXUS ST measures steam flow non-invasively from the outside of the pipe. Non-invasive steam flow measurement means measuring without any interruption of operation and supply. Since clamp-on ultra-sonic transducers are simply mounted on the outside of the pipe, it requires just minimal installation effort and no opening of the pipeline.

The acoustic measuring method proves to be impressive with its exceptionally high measuring dynamics, is highly sensitive even at very low flow velocities and functions independently of the flow direction. Due to this large flow range (flow velocities from 0.01 m/s up to 60 m/s), there is no need to reduce pipe diameter to fit an inline meter’s requirement of minimum flow velocity. Moreover, the non-invasive measurement does not cause any pressure loss. The transducer mountings can be completely insulated to reduce any heat loss to the environment.

With FLUXUS ST, for the first time ever, it is possible to capture all steam usage from very low to very high flow rates with one meter size.

Completely maintenance-free

Non-invasive steam flow measurement also means measuring without direct contact with the medium flowing in the pipe. FLUXUS ST has no moving parts. Therefore, FLUXUS ST is not subjected to wear and tear and does not require any maintenance.

FLUXUS ST measures volume and mass flow of saturated and super­heated steam at temperatures up to 180 °C. The clamp-on ultrasound system is available as both a stationary and a portable meter.

Fixed and versatile

FLUXUS G721 ST is the stationary flow meter for steam and offers a variety of digital communication interfaces such as Profibus, Modbus RTU, TCP and others.

100% process availability is guaranteed when using a FLEXIM solution – the installation of a FLUXUS G721 ST can be done within 2 hours onto the hot pipe.



  • Reliable and non-invasive steam measurement
  • High dynamic flow range
  • Easy and cost-efficient retrofit 
  • No risk of leakage, no pressure loss
  • Integrated mass flow measurement

Technical Facts

Flow channels
1 or 2
saturated steam, superheated steam
Process temperature
max. 180°C
Process pressure
min. 3 bar abs.
Pipe diameter range
45 mm…400 mm
Flow velocity range
0,01m/s…60m/s (depending an pipe size and transducer)
Measurement range
±1% ... 3% of reading, ±0,01 m/s, depending on application
±0,15% of reading, ±0,01 m/s
Communication Protocol
Modbus RTU, Modbus TCP, Profibus PA, FF H1, BACnet MS/TP, BACnet TCP
Digital communication
USB Interface
Additional Information
please have your specific application always tested for feasibility





Technical specification
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