The float level switch B-4 are used to keep between 2 points the level of liquid like water, oil, chemical products, etc., conductive or not, in tanks or recipients at atmospheric pressure.

The B-4 bases their work due to the movement of a float. When the level of liquid rises up, the float reaches the mechanical stop and pull up the rod. This enables the action of the lever and reverses the position of the switch.

The adjustment of the commutation of the switch is obtained adjusting the mechanical stops at the desired rod point. If the float is blocked with the mechanical stops, it can be obtained only one punctual signal.

It is simple: the float must be vertically installed on the top of the tank with an appropiate support to fix it or through a M12 hole. The tank can have a cap to preserve the liquid against dust. Just a M12 hole in the cap allows the free movement of the rod.


Approximate measures given in mm.

Technical data

NameFloat switch
TypeB-4 – ref: 2505-6
Rod length500 mm
Product density0,76 Kg/l
Tank pressureAtmospherical
Maximum pressure+0.5 bar
Cable entry3 of M20X1.5
Switching voltage250 V AC
Switching function1 NO + 1 NC Double-Pole Double-Throw (DPDT)
Capacity of the contact3 A / 230 V AC (for resistive loads)
For inductive or capacitive loads, reduce at 50%
Ambient temperature-20° C – +70° C
ProtectionIP40 according to DIN EN60529
Weight0,56 Kg
Float weight0,12 Kg
FloatStainless Steel 1.4401
RodStainless Steel 1.4401

Explore all our level controls

Need more information?