Paddle flow switches, reed switch contact, 1/2” male thread

Main uses: The most simple and price effective flow switch of the range. Used for water flow detection on small size water pipes.


Flow sensing

Main housing material

Paddle material

Mounting position

Mounting type



Electrical rating

Ingress protection

Wire lengths (mm)

, ,

Maximum flow detection (L/min)

Minimum flow detection (L/min)

Nominal pressure at 20°C

Max operating temperature (°C)

Liquids temperature range (°C)

This product is currently out of stock and unavailable.

SKU: N/A Category:


Size and pressure Flow sensing:

Gravity pull back paddle


1/2” BSPP thread


Reed switch, Open on
flow rise

Electrical rating Mounting position Type





R1L (1/2”BSPP)

1: Paddle

2: Body

3: Cable


R1G (1/2”NPT)

1: Paddle

2: Body

3: Cable

Main uses: The most simple and price effective flow switch of the range. Used for water flow detection on small size water pipes. CONTACT OPENS BY FLOW RISE.

Functional principle:

Balanced magnetic paddle mounted perpendicular to the flow and activating a reed switch through the wall. The return of the paddle is by gravity, 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. Not to be used for water containing magnetic particles or high viscosity liquids, which block the movement of the paddle.

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

Paddle: Polypropylene, 18mm 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 close, open by flow rise

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

Nominal pressure at 20°C: 1MPa (PN10)

Assembly on pipes:

R1G minimum pipe diameter

R1L minimum pipe diameter



Average Flow detection values vs pipe I.D. and paddle length (Liters/min)


Paddle length

Pipe ID (mm)***

25 32 40 50 63
*Close **Open *Close **Open *Close **Open *Close **Open *Close **Open
1 12.7 10.8 17 13.5 28 23 46 42 93 83
** Open by flow rise (L/min) of contact close at no flow position * Close by flow decrease (L/min) of contact close at no flow position. Average values for indication only. Standard tolerances ±30%

Nominal diameter: Usually used on 25 to 32 mm internal diameter pipes. The paddle is not cleavable.

Mandatory mounting position: On vertical pipes, with horizontal flow switch axis, and paddle upside.  Upstream flow only.

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
  • 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

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
Thread 500mm 1m 2m
½” BSPP R1L611536F45P050 R1L611536F45P100 R1L611536F45P200
 ½” NPT  R1G611536F45P050  R1G611536F45P100  R1G611536F45P200


Technical specifications sheet