Series FS-2 Vane Flow Switch

Low Cost, Field Adjustable Set Point and Paddle

The SERIES FS-2 Vane Flow Switches offers an economical flow proving solution. The FS-2 paddles are adjustable to fit 1 to 8" size pipe.

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Product Applications

  • Boiler flow proving
  • Hot water heaters
  • Chillers
  • Cooling lines
  • Machinery
  • Liquid transfer systems

Models & Ordering

Model Description Usually Ships Price Order
Ships: Next Day
Price: $48.50
Paddle flow switch, 1" male NPT. Next Day $48.50 Order
Ships: Next Day
Price: $48.50
Paddle flow switch, 1" male BSPT. Next Day $48.50 Order
Ships: Next Day
Price: $48.50
Paddle flow switch, NPT process connection, conduit electrical connection Next Day $48.50 Order
Ships: Consult Factory
Price: $48.50
Paddle flow switch, 1" male NPT connection with 8 ft leads Consult Factory $48.50 Order


Compatible liquids.
Wetted Materials:
Bellow: Tin-bronze; Vane: SS; Body: Forged brass.
Temperature Limits:
230°F (110°C).
Pressure Limits:
145 psig (10 bar).
Enclosure Rating:
NEMA 4 (IP64).
Switch Type:
SPDT snap switch.
Electrical Rating:
10 A res, 3 A ind @ 250 VAC.
Electrical Connection:
Cable gland with attached wire leads or optional conduit connection.
Process Connection:
1" male NPT or BSPT.
Mounting Orientation:
Switch must be installed vertically on horizontal pipe runs.
Set Point Adjustment:
Four vane combinations and an adjustment screw.
Die-cast aluminum alloy.
28.22 oz (0.8 kg).
Agency Approvals:


  • Field adjustable set point adjustment screw allows for easy flow switch modification
  • Custom application set points enabled by field adjustable vane layers
  • Aluminum weatherproof housing permits outdoor installation


Model Number Description Usually Ships Price Order
Replacement vane assembly FS-2-VANE Replacement vane assembly Next Day $6.10 Order

Product Literature


Catalog Pages




What does actuation and de-actuation mean?
Actuation means that the flow rate has reached a point where the microswitch trips or the contacts of the microswitch change state. De-actuation means that the flow rate has decreased to a point where the microswitch returns to its normal state.
On your Flow Switches, which model has a Form C type contact
Form C contact is a SPDT snap switch. Many of Dwyer’s flow switches have SPDT snap switches. The V4, V6, V7, FS-2, and V8 are some of them.

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