The Sensata FS series flow switches are reed switch-based devices designed for reliable flow/no-flow detection in liquid systems. The design incorporates a moving magnet and a fixed reed switch, providing a normally open (N/O) contact closure when flow is present. The advanced design ensures minimal fluid flow restriction and low pressure drop, making these switches suitable for a wide range of industrial fluid monitoring applications.

Key Features

• Reliable Reed Switch Technology: The magnetic actuation mechanism ensures long-term reliability without mechanical wear. The hermetically sealed reed switch provides protection against environmental contaminants.
• Low Flow Restriction: The internal flow path is optimized to minimize pressure drop, reducing pumping energy requirements and maintaining system efficiency.
• Compact Design: Available in 15mm and 22mm tube connection versions, these flow switches fit easily into space-constrained installations.
• WRAS Approval: Select models (FS15A, FS22A, FS15LF, FS22LF) are WRAS approved for use in cold and hot water systems up to 60°C, making them suitable for potable water applications.
• Low Flow Versions: FS15LF and FS22LF models provide detection ranges as low as 0.75-1.75 L/min for applications requiring low flow sensitivity.
• Wide Media Compatibility: Compatible with water, weak acidic liquids, and other non-aggressive fluids. The acetal resin body provides good chemical resistance.

Technical Specifications

• Available Models: FS15A (15mm, 0.53 GPM trip), FS22A (22mm, 0.99 GPM trip), FS15LF (low flow, 0.24 GPM trip), FS22LF (low flow, 0.99 GPM trip), FS22LF-01 (low flow, 0.75 L/min)
• Port Size: 15mm (19/32", 0.59") or 22mm (7/8", 0.87")
• Switch Function: Normally Open (N/O) – closes on flow
• Maximum Switching Voltage: 240 VAC, 120 VDC
• Maximum Switching Current: 1A (resistive load)
• Maximum Switching Power: 15 VA
• Lead Wire Length: 25 cm (9.8") PVC insulated cable
• Mounting Orientation: Horizontal or vertical (flow direction indicated on body)
• WRAS Certification: FS15A, FS22A, FS15LF, FS22LF (up to 60°C)
• Low Flow Range (FS15LF): 0.24 GPM trip, 0.07 GPM release (approx. 0.9-1.7 L/min)
• Low Flow Range (FS22LF): 0.75-1.75 L/min (0.20-0.46 GPM)

Applications

The FS series flow switches are ideal for liquid flow monitoring in industrial automation, water treatment, cooling systems, HVAC, pump protection, leak detection, and process control systems. WRAS-approved models are suitable for potable water applications.