FS-105E – Series Adjustable Flow Switch

The FS-105E model flow switch operates in any mounting position. It is equipped with a calibrated piston which is displaced by flow to magnetically actuate a sealed hermetic reed switch. When flow decreases a positive spring returns the piston to its prior position and de-actuates the reed switch. The reed switch assembly is movable to allow for customer setting of flow rate within the limits of the switch selected. The adjustment does not effect the flow path, therefore pressure drop is not influenced when changing set-points. Versions are available for Liquid and Gas flow. Robust components allow a pressure of 250 bar, ideally suited for high pressure cleaning and lubrication systems.


When the magnetic field of permanent magnet inside the shuttle or piston is moved into the proximity of the reed switch inside the stationary stem, the reed switch contacts “snap” together and closes the electrical circuit. When the magnetic field is moved away from the reed switch, the reed switch contacts move apart and the circuit is opened.

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Max flow
100% above max. set-point range
Max operating pressure
250 bar
Operating temperature
20° to 120°C
Adjustable ranges
0.005-150 l/min
Mounting orientation
Any position
G1/4, G1/2, G1
Electrical connection
Din 43650,
Electrical contact rating
NO - 250V, 1A, 100VA - G1 port, SPDT - 250V, 1.5A, SPDT - 200V, 1A 20VA