RS PRO Piston Inline Flow Switch for Liquid, 0.04 L/min Min, 0.13 L/min Max
RS Stock No. 510-0559
Brand RS Pro
- Connection Type: 1/4 BSP
- Current Rating: 1 A
- Maximum Media Temperature: +100°C
AED 1.605.24
in stock now
RS PRO Paddle Flow Switch for Gas, Liquid, 4 L/min Min, 5.5 L/min Max
RS Stock No. 613-4216
Brand RS Pro
- Current Rating: 5 A
- Maximum Media Temperature: +110°C
- Media Monitored: Gas, Liquid
AED 1.422.00
in stock now
RS PRO Paddle Flow Switch for Gas, Liquid, 5.5 L/min Min, 7 L/min Max
RS Stock No. 613-4238
Brand RS Pro
- Device Type: Paddle
- Material: Nickel Plated Brass
- Maximum Operating Temperature: +110°C
AED 1.493.45
in stock now
RS PRO Piston Inline Flow Switch for Liquid, 0.1 L/min Min, 0.6 L/min Max
RS Stock No. 510-0565
Brand RS Pro
- Maximum Flow Rate: 0.6 L/min
- Maximum Media Temperature: +100°C
- Media Monitored: Liquid
AED 1.629.22
in stock now
RS PRO Piston Inline Flow Switch for Liquid, 0.5 L/min Min, 3 L/min Max
RS Stock No. 510-0571
Brand RS Pro
- Maximum Flow Rate: 3 L/min
- Maximum Operating Temperature: +120°C
- Media Monitored: Liquid
AED 1.693.61
in stock now
RS PRO Paddle Flow Switch for Gas, Liquid, 7.5 L/min Min, 10 L/min Max
RS Stock No. 613-4222
Brand RS Pro
- Material: Nickel Plated Brass
- Maximum Media Temperature: +110°C
- Maximum Pressure: 25bar
AED 1.546.53
in stock now
RS PRO Paddle Flow Switch for Gas, Liquid, 14 L/min Min, 18 L/min Max
RS Stock No. 613-4244
Brand RS Pro
- Connection Type: 1 BSP Female
- Minimum Flow Rate: 14 L/min
- Supply Voltage: 250 V ac
AED 1.864.82
in stock now
RS PRO Handle Pneumatic Relay Micro Valve, R 1/8, 3.175mm, III B
RS Stock No. 176-2138
Brand RS Pro
- Category: Pneumatic Manual Control Valves
- Control Button/Switch Colour: Red
- Maximum Operating Temperature: +80°C
AED 557.86
in stock now
RS PRO Handle Pneumatic Relay Micro Valve, R 3/8, 9.525mm, III B
RS Stock No. 176-2140
Brand RS Pro
- Maximum Flow Rate: 3.1m³/h
- Minimum Operating Temperature: -20°C
- Thread Size: 9.525mm
AED 610.23
in stock now
RS PRO Handle Pneumatic Relay Micro Valve, R 1/8, 3.175mm, III B
RS Stock No. 176-2141
Brand RS Pro
- Control Button/Switch Colour: Red
- Thread Size: 3.175mm
- Thread Standard: ISO 7
AED 557.86
in stock now
RS PRO Push Pull 4/2 Pneumatic Manual Control Valve BHP Series, Push In 4 mm, 4mm, III B
RS Stock No. 784-0072
Brand RS Pro
- Control Button/Switch Colour: Red
- Control Mechanism: Push Pull
- Maximum Operating Pressure: 16 bar
AED 302.80
in stock now
RS PRO Handle Pneumatic Relay Micro Valve, R 1/4, 6.35mm, III B
RS Stock No. 176-2139
Brand RS Pro
- Control Button/Switch Colour: Red
- Maximum Operating Pressure: 20 bar
- Thread Standard: ISO 7
AED 583.22
in stock now
RS PRO Handle Pneumatic Relay Micro Valve, R 1/4, 6.35mm, III B
RS Stock No. 176-2142
Brand RS Pro
- Category: Pneumatic Manual Control Valves
- Number of Ports: 2
- Thread Size: 6.35mm
AED 583.22
in stock now
RS PRO Handle Pneumatic Relay Micro Valve, R 3/8, 9.525mm, III B
RS Stock No. 176-2143
Brand RS Pro
- Connection Port Thread: R 3/8
- Maximum Operating Pressure: 20 bar
- Minimum Operating Temperature: -20°C
AED 603.84
in stock now
RS PRO Push Pull 4/2 Pneumatic Manual Control Valve ACV Series, Push In 6 mm, 6mm, III B
RS Stock No. 784-0076
Brand RS Pro
- Control Mechanism: Push Pull
- Number of Ports: 4/2
- Thread Size: 6mm
AED 430.58
in stock now
SMC Flow Switch Series Digital Flow Switch Flow Switch for Dry Air, N2, 30 L/min Min, 3000 L/min Max
RS Stock No. 281-0919
Brand SMC
- Maximum Flow Rate: 3000 L/min
- Media Monitored: Dry Air, N2
- Minimum Flow Rate: 30 L/min
AED 4.688.05
in stock now
SMC PF2A Series Digital Flow Switch Flow Switch for Air, 25 l/min Min, 525 L/min Max
RS Stock No. 270-4283
Brand SMC
- Category: Flow Sensors
- Maximum Flow Rate: 525 L/min
- Series: PF2A
AED 3.135.84
in stock now
SMC PFM7 Series Digital Flow Switch Flow Switch, 0.2 l/min Min, 10 L/min Max
RS Stock No. 270-4301
Brand SMC
- Category: Flow Sensors
- Maximum Flow Rate: 10 L/min
- Series: PFM7
AED 1.465.66
in stock now
SMC PF2M7 Series Digital Flow Switch Flow Switch, 1 L/min Min, 100 L/min Max
RS Stock No. 281-0917
Brand SMC
- Maximum Flow Rate: 100 L/min
- Series: PF2M7
- Supply Voltage: 12 → 24 V dc
AED 1.255.36
in stock now
SMC PF2W Series Digital Flow Switch Flow Switch for Water, 2 L/min Min, 16 L/min Max
RS Stock No. 281-0918
Brand SMC
- Device Type: Digital Flow Switch
- Minimum Flow Rate: 2 L/min
- Series: PF2W
AED 3.229.33
in stock now
SMC PF3W Series Digital Flow Switch Flow Switch for Water, 2 L/min Min, 16 L/min Max
RS Stock No. 281-0921
Brand SMC
- Maximum Flow Rate: 16 L/min
- Media Monitored: Water
- Minimum Flow Rate: 2 L/min
AED 2.938.77
in stock now
Endress+Hauser DTT31 Series Thermal Flow Switch Flow Switch for Liquid, 0.03 m/s Min, 3 m/s Max
RS Stock No. 069-0253
Brand Endress+Hauser
- Category Link: https://ae.rsdelivers.com/browse/electrical-automation-cables/automation-control-gear/sensors/flow-sensors
- Series: DTT31
- Supply Voltage: 18 → 30 V dc
AED 1.778.77
in stock now
Endress+Hauser DTT31 Series Thermal Flow Switch Flow Switch for Liquid, 0.03 m/s Min, 3 m/s Max
RS Stock No. 069-0254
Brand Endress+Hauser
- Category Link: https://ae.rsdelivers.com/browse/electrical-automation-cables/automation-control-gear/sensors/flow-sensors
- Series: DTT31
- Supply Voltage: 18 → 30 V dc
AED 1.778.77
in stock now
ifm electronic SI5000 Series Flow Switch Flow Switch for Gas, Liquid, 3cm/s (liquid), 200cm/s (gas) Min, 300cm/s
RS Stock No. 230-9410
Brand ifm electronic
- Device Type: Flow Switch
- Section: Automation & Control Gear
- Super Section: Sensors
AED 1.870.89
in stock now
...
What is a flow switch?
How does a flow switch work?
What are the main types of flow switches?
- Paddle (or vane) flow switch: A flat paddle or vane is pushed by the flowing fluid to actuate a switch. Ideal for clean liquids and straightforward installation.
- Turbine (or impeller) flow switch: An inline turbine spins with the flow; rotation triggers the switch. Suitable for higher flow rates and precise control.
- Differential-pressure flow switch: A restriction creates a pressure difference that is monitored by a sensor; changes in flow alter the differential pressure and switch state.
- Magnetic or reed switch flow switch: A magnetically actuated sensor detects flow without direct contact, useful in sanitary or low-leakage applications.
- Ultrasonic or thermal flow switches (less common as discrete options): Use flow-induced changes in transit time, density, or heat transfer for switching in special environments.
Where are flow switches used?
- HVAC systems to start/stop circulation pumps based on differential flow in heating or cooling loops
- Water treatment and filtration plants for pump protection and backflow prevention
- Industrial automation lines where process sequences depend on fluid movement
- Plumbing systems to guard against dry-running of pumps
- Chemical processing and pharmaceutical manufacture where sanitary, compliant sensing is required
- Food and beverage processing where clean-in-place (CIP) compatibility is important
- Oil and gas, petrochemical, and power generation applications with robust environmental ratings
How do I choose the right flow switch?
Ensure the switch activates at the operational flow rate required by the control system. Materials (stainless steel, PVC, brass), seals, and coatings must resist the process fluid (water, oil, chemicals, slurry). Choose ratings that exceed process conditions to avoid failure. Output type (NO/NC, changeover), contact rating, and supply voltage must match the controller or PLC. Straight-run length, presence of elbows, and accessibility for maintenance. For outdoor or hazardous environments, select appropriate enclosure protection (IP ratings) and certifications (CE, RoHS, ATEX/IECEx if applicable). Some switches require periodic calibration or cleaning, especially paddle and turbine types in dirty systems.
How do I install and wire a flow switch?
- Turn off power to the control circuit and depressurize the line before installation.
- Install in a straight section of pipe with adequate straight-run distance before and after the sensor to avoid turbulence.
- Choose the correct orientation and connection type (threaded, flanged, or compression) for your piping system.
- Use appropriate gaskets, seals, and torque specifications to prevent leaks or motion-induced wear.
- Connect the output to the correct input on the control system or PLC, observing NO/NC configuration and any required pull-up or pull-down resistors.
- Verify electrical ratings, supply voltage, and safety certifications; if the switch is explosion-proof or weather-proof, ensure proper enclosure is used.
- Once mounted, test with a known flow condition and confirm that the controller responds as intended, adjusting setpoints if available.
How do I troubleshoot a flow switch that isn’t responding?
- Check power and wiring: confirm supply, correct grounding, and that the control inputs match the switch output (NO/NC).
- Inspect the sensing element: paddle or turbine can jam with debris, scale, or sediment; clean or replace if necessary.
- Verify setpoint and hysteresis: ensure the adjustable range aligns with the actual flow in the system.
- Look for leaks or incorrect installation: misalignment or air ingress can affect readings, especially in differential-pressure switches.
- Test with a simulated flow source: bypass or temporarily increase flow to confirm switch activation.
- Check for electrical interference or wiring damage that could mask signals or trigger spurious outputs.
- Ensure the media temperature and chemical compatibility have not degraded seals or sensor components.
What maintenance and replacement considerations apply to flow switches?
- Periodic cleaning of the sensing element to prevent buildup that reduces sensitivity.
- Inspection of seals, gaskets, and enclosure integrity to maintain IP/ATEX ratings where required.
- Calibration checks and, if available, recalibration according to the manufacturer’s schedule or process requirements.
- Replacement of worn or damaged parts, such as paddle blades, impellers, or reed contacts, to preserve accurate switching.
- Verification of electrical connections and corrosion-resistant fittings in aggressive environments.
- Documentation of changes for process history and quality standards in regulated industries.
What related components should I consider with a flow switch?
- Flow meters and flow sensors for precise measurement alongside switching actions
- Differential-pressure transmitters and pressure switches for multi-point control
- Valves, actuators, and pumps with compatible electrical interfaces
- Filters, strainers, and strainers upstream to protect the sensing element
- Tubing, fittings, and seals designed for the process fluid and temperature
- Control relays, PLCs, and safety interlocks with appropriate input ratings
- Sanitary and hygienic versions for food, beverage, or pharmaceutical lines
Are flow switches suitable for hazardous environments or special certifications?
- Explosion-proof or intrinsically safe variants for hazardous areas
- ATEX and IECEx certifications where required by local regulations
- IP65/IP66 or higher ingress protection for washdown and outdoor installations
- Materials compatible with aggressive chemicals or high-temperature media
- Compliance with industry standards such as CE, UL, CSA, RoHS, and REACH