Control of liquids

Pneumatic controllers


Intended use:

The pneumatic level controller is used to control 1 level in liquids at atmospheric pressure. Model with electrical microswitch output, DIN 43650 Connector and IP65.
Besides liquids can control fluid mixtures that allow the tube to be cleaned after the level of mixture downs.

The liquid or mixture that is controlled must not emit vapours that rarify the entrapped air inside the tube. This could be provoke a misfunction of the device. 


The controllers bases their function on the pneumatic outline. The controllers have an electric microswitch activated due to a membrane sensitive to pressure.

The action on the microswitch is carried out by the pressure of the air column entrapped inside the tube and the pressure chamber. Depending on the model, a water height of 40 mm.w.c. is sufficient to trigger the switch.

There are models with a micro pneumatic valve and there are other models that activate the switch due to a depression.
The models with sensitivity adjustment “SR”, the models with double signal “DS”and the models with “A99” switch have a regulation system with a spring that allows the adjusment of the sensitivity. Tightening the regulation nut to reduce the sensitivity and increase the strain of the liquid to activate the microswitch. 

Mechanical connection:

Make a hole wide enough to introduce the tube or fix it with the mounting accesory usuable.

Ensure of the water-tightness of the unions. Do not use tow or Teflon tapes, only screw the tube to the housing up to the base gasket.

In lateral mounting, ensure of a minimum height of the tube of 200 mm minimum after the elbow. 


Aproximate measures are given in mm. 




Technical data:

Name Pneumatic controller  
Type L-30 ref: 2401-0-030
  L-30 Viton-Parylene ref: 2402-1-301
Type of signal Single signal  
Actuating pressure Above the tube inlet; ±20 mm WG  
  L-30 +60 mm WG
  L-30 Viton-Parylene +100 mm WG
Tank pressure Atmospherical  
Maximum pressure +0.5 bar  
Cable entry DIN 43650 Connector  
Electric microswitch:    
Switching voltage 250 V AC  
Switching function 1 NO + 1 NC  
Capacity of the contact 6 A / 250 V AC
(for resistive loads)
For inductive or capacitive loads reduce at 50%
Ambient temperature -5 °C ... +60 °C  
Type of protection IP53 According DIN EN60529  
Weight 1.50 kg  
Housing and cap Polyamide and Polycarbonate  
Pressure chamber (base) PVC  
Membrane NBR
(Under request Viton-Parylene)
Base gasket EPDM  
Xicle antiturbulence (under request) Brass  
Tube connection screw G 1 " female
(Under request mounting accesory in PVC or S.S. G 1/2 " female)