Products
View some of our proven products from leading manufacturers, selected to deliver reliable solutions and supported across the UK.
ST51 Mass Flow Meter
A versatile insertion thermal mass flow meter for biogas, natural gas and compressed air applications in pipes above 2″.
Well suited to industrial gas duties, including dirty, wet and low-pressure gas measurement.
The FCI ST51 Thermal Mass Flow Meter is a cost-effective, ATEX-certified insertion thermal mass flow meter designed for reliable gas flow measurement in industrial and renewable energy applications.
Widely used throughout the biogas, compressed air and natural gas industries, the ST51 provides accurate direct gas mass flow measurement with simple installation, low maintenance requirements and excellent low-flow sensitivity.
Its insertion-style design allows the meter to be installed or removed under process pressure using a standard full-bore ball valve, minimising downtime and simplifying maintenance and commissioning activities.
The ST51 is particularly well suited to:
- Biogas flow measurement
- CHP gas monitoring
- Waste gas burner monitoring
- Flare gas monitoring
- Compressed air systems
- Natural gas applications
- Utility gas measurement
The meter is commonly specified for anaerobic digestion plants and renewable gas systems due to its reliability in wet and variable gas conditions.
The ST51 also supports compliance with OFGEM RHI requirements for gas flow measurement to waste gas burners, flare systems and CHP units.
Designed for Industrial & Biogas Applications
Using proven thermal dispersion technology, the ST51 measures gas mass flow directly without requiring separate pressure or temperature compensation.
This provides several advantages:
- Reliable low-flow sensitivity
- Stable measurement across varying gas conditions
- No moving parts
- Minimal pressure drop
- Reduced maintenance requirements
The ST51 is especially effective in applications involving:
- Wet or saturated biogas
- Variable methane concentrations
- Low-pressure gas systems
- Utility and process gases
Simple Installation & Operation
The ST51 is designed for fast and straightforward installation across a wide range of pipe sizes.
Its live insertion and removal capability allows maintenance or replacement without full process shutdown, making it ideal for operational industrial environments.
Optional local LCD indication provides clear display of:
- Instantaneous flow rate
- Totalised flow
Key Features
- Insertion thermal mass flow meter for gases
- Direct gas mass flow measurement
- ATEX certified
- Live insertion and removal capability
- No pressure or temperature compensation required
- No moving parts for reduced maintenance
- Optional LCD display for flow rate and total flow
- Fully programmable electronics
Process & Performance Features
- ATEX certified
- 316 stainless steel wetted parts
- Process temperatures up to +121°C
- Pipe sizes from 1½” to 36”
- 2 x 4-20mA outputs and pulse output
Typical Applications
- Biogas flow measurement
- CHP monitoring
- Flare gas monitoring
- Waste gas burners
- Compressed air systems
- Natural gas monitoring
- Utility gas applications
Key Benefits
- Cost-effective industrial gas flow measurement
- Reliable operation in wet and variable biogas conditions
- Excellent low-flow sensitivity
- Simple installation and maintenance
- Suitable for hazardous area applications
- Supports OFGEM RHI compliant gas monitoring systems
Over 45 Years in Operation
1000's of UK Installations
Supporting 100's of UK Sites
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