Types R1S and R1F: Paddle flow switches, reed switch contact, 1/2" male thread, long paddle

Main uses: The most simple flow switch with magnetic pull-back. Recommended mounting position is on horizontal pipes, but can be mounted in any position.  For water flow detection on dia. 25 to 63mm water pipes

Functional principle:

Balanced magnetic pallet mounted perpendicular to the flow and activating a reed switch through the wall. The return of the pallet is by made by magnetic action, without spring. No seal or liquid can pass between the piping system and the electrical contact. Suitable for corrosive water pools and spas and salination chlorination and bromination systems. Must not be used for water containing magnetic particles or high viscosity liquids, which block the movement of the pallet.


– By cleaving the paddle

Main housing material: Polypropylene, resistant to ozone and water disinfection products, usable with potable water.

Paddle: Polypropylene, 13 mm width

Paddle shaft: Titanium, providing an outstanding corrosion resistance, and improved mechanical live

Electrical rating: Max 1A, Max 70W, Max 250V, resistive load. Use on inductive circuits reduces electrical rating. We recommend to protect the reed switch with contact protection device when used in inductive loads

Electric contact type: Normally open, closes by flow rise

Liquids compatibility: For use with clean water and liquids without magnetic particles and without chemical incompatibility with  polypropylene and titanium

Nominal pressure at 20°C: 1MPa (PN10)

*Close by flow rise (L/min) of contact open at no flow position  **Open by flow decrease (L/min) of contact open at no flow position. Average values for indication only. Standard tolerances ±30%


Nominal diameter: Can be used on 25 to 63 mm internal diameter pipes

The paddle is cleavable and can be cut at various lengths upon pipe diameter. There are cutting lines numbered 1 to 6 every 5mm.

Recommended mounting position: On horizontal pipes. Mounting in other positions slightly modify the calibration

Water pipe connection:  On female ½” fitting.  On the type with BSPP thread, a NBR gasket is supplied with the product. On the type with NPT thread, thread sealant must be used Recommended torque: 7Nm

Liquids temperature range: 5 to 80°C

Ambient temperature range: 5 to 50°C

Ingress protection: IP65

Electrical connection: 2 x AWG24 (0.2mm²) cable, PVC insulation, T80°, style UL2464.

Installation instructions:

– Check carefully the paddle orientation: The arrow on housing must be exactly parallel to the pipe

– A 5 mm minimum gap must be respected between end of the paddle and tube wall opposite to the fitting.

– We recommend the use of nozzles of length less than or equal to 18mm between the gasket seat and the inside of the tube and with  an inner diameter greater than or equal to 20 mm, to avoid blocking of the pallet

Accessories: 1/2″ PVC saddles for DN40 to DN100 (OD) PVC pipes, and other fittings: see last section of this catalogue

Options: cable with connector or terminals, other cable length


Main references


Cable length





R1S6D4771F45P050 R1S6D4771F45P100 R1S6D4771F45P200
½NPT R1F6D4766F25P050 R1F6D4766F25P100



2D&3D Drawing