Ameritrol FX Series Flow Switch

Features:

• Designed for line sizes 1/2” and larger
• Suitable for hazardous areas with explosion-proof and NEMA 4X rated enclosures
• 316L stainless steel sensor standard; exotic alloys available for enhanced corrosion resistance
• Operating temperatures up to 900°F
• Pressure ratings up to 10,000 PSIG
• Capable of detecting extremely low flow rates
• Field-programmable relay outputs
• No moving parts for maximum reliability and minimal maintenance

Operation

The FX Series flow switch utilizes proven thermal dispersion technology to deliver highly reliable and repeatable flow detection in demanding industrial environments. With no moving parts, the design eliminates mechanical wear and significantly reduces maintenance requirements.

The sensing element incorporates two temperature sensors: one is heated with a constant low-power source, while the second measures the process temperature. As flow velocity changes, the temperature differential between the sensors shifts accordingly, providing a precise indication of flow conditions.

This differential allows the instrument to function as a flow/no-flow switch or to actuate at a specific velocity based on application requirements. Optional dual setpoints enable independent adjustment of two switching thresholds within a single device.

With turndown capabilities up to 300:1, the FX Series can detect extremely low flow rates across a wide range of liquids, gases, and slurries—including viscous and corrosive media. The robust sensor design withstands process conditions up to 900°F and 10,000 PSIG.

A variety of process connections are available, including threaded, flanged, and retractable probe configurations. Electronics can be supplied with single or dual relay outputs, and optional temperature monitoring is available via switch output or 4–20 mA signal. Remote-mounted electronics are recommended for high-temperature or difficult-to-access installations.

Applications:

The FX Series is engineered for versatility across a broad range of industrial processes, including:

• Pump Protection: Automatic shutdown on low or no-flow conditions
• Lubrication Systems: Verification of bearing lubrication flow
• Seal Monitoring: Detection of seal leakage or confirmation of seal flow
• Chemical Injection: Monitoring low flow rates in metering and dosing systems
• Safety Systems: Flow detection in safety showers and eyewash stations with alarm integration
• Analytical Equipment: Ensures continuous sample flow to analyzers and gas chromatographs
• Process Monitoring: Status indication for pumps, valves, and fans in control systems
• Purge Air Systems: Verification of airflow for safety compliance
• Spray Systems: Detection of blocked or fouled spray nozzles
• Relief Systems: Monitoring flow through relief valves and rupture disks
• Thermal Systems: Protection of heaters and chillers from low-flow conditions
• Loading Operations: Detection of phase changes during tank car loading
• Drain Lines: Reliable sensing in partially filled or low-flow conditions
• Agitation Monitoring: Confirms mixing activity in tanks and vessels
• Flare Systems: Ideal for monitoring dirty or particulate-laden gases in flare stacks